EXAMINING A VISUOSPATIAL/VISUOMOTOR TRAINING PROGRAM AS AN INTERVENTION TO INDUCE COGNITIVE IMPROVEMENT DURING ACUTE POST-STROKE RECOVERY by Mireille Rizkalla BSc., University of Toronto, 2008 THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN PSYCHOLOGY UNIVERSITY OF NORTHERN BRITISH COLUMBIA May 2011 © Mireille Rizkalla, 2011 1+1 Library and Archives Canada Bibliotheque et Archives Canada Published Heritage Branch Direction du Patrimoine de I'edition 395 Wellington Street Ottawa ON K1A0N4 Canada 395, rue Wellington Ottawa ON K1A 0N4 Canada Your file Votre reference ISBN: 978-0-494-87564-3 Our file Notre reference ISBN: 978-0-494-87564-3 NOTICE: AVIS: The author has granted a non­ exclusive license allowing Library and Archives Canada to reproduce, publish, archive, preserve, conserve, communicate to the public by telecommunication or on the Internet, loan, distrbute and sell theses worldwide, for commercial or non­ commercial purposes, in microform, paper, electronic and/or any other formats. L'auteur a accorde une licence non exclusive permettant a la Bibliotheque et Archives Canada de reproduire, publier, archiver, sauvegarder, conserver, transmettre au public par telecommunication ou par I'lnternet, preter, distribuer et vendre des theses partout dans le monde, a des fins commerciales ou autres, sur support microforme, papier, electronique et/ou autres formats. The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. L'auteur conserve la propriete du droit d'auteur et des droits moraux qui protege cette these. Ni la these ni des extraits substantiels de celle-ci ne doivent etre imprimes ou autrement reproduits sans son autorisation. In compliance with the Canadian Privacy Act some supporting forms may have been removed from this thesis. Conformement a la loi canadienne sur la protection de la vie privee, quelques formulaires secondaires ont ete enleves de cette these. While these forms may be included in the document page count, their removal does not represent any loss of content from the thesis. Bien que ces formulaires aient inclus dans la pagination, il n'y aura aucun contenu manquant. Canada Abstract Purpose: A novel visuospatial (VS) /visuomotor (VM) cognitive training program was examined as an intervention tool to improve acute post-stroke recovery. Method: A randomized controlled trial was conducted with 9 experimental participants (age 65 ± 9.31) and 9 controls (age 67 ± 7.81). Intervention training included 1 hour/ 5-days a week for 4 weeks. Pre-and post-training neuropsychological measures were utilized as determinants of program success. Results: Compared to controls, the intervention group displayed significant gains on all outcome measures including: global (MMSE, p = .002), language (BN, p - .001), VS (Rey-O, p = .011), memory (HVLT, p = .005), executive function (Animal, p = .001), mood (GDS, p = .020) and functional ability (DAD, p = .008). Conclusion: VS/VM cognitive training results in improved cognition, function and mood beyond the outcomes of traditional intervention alone. Thus, this innovative type of intervention shows promise for revolutionizing current stroke rehabilitation. ii TABLE OF CONTENTS Abstract Table of Contents List of Tables List of Figures List of Appendices Acknowledgement ii iii v vi vii viii Introduction Societal Burden Associated with Stroke Secondary Stroke Overview 1 2 3 Best Practice for Stroke Care Units Best Practice for Timing of Stroke Rehabilitation Best Practice for Intensity of Therapy British Columbia's Stroke Strategy 4 4 6 7 8 Stroke Best Care Practice Literature Review on V isuospatial/Visuomotor Cognitive Training 9 Defining the Evaluation Process of Cognitive Intervention Remediation of Neglect and V isuospatial/Visuomotor Deficits Training Effectiveness of Visual Scanning Training Effectiveness of Complex Visuospatial Skills Video-Gaming Training Effectiveness Visual Imagery Training Effectiveness Visuospatial/Visuomotor Cognitive Intervention 10 11 12 14 17 19 23 Cognitive Training Project Rationale Summary of Project Elements Objectives Hypothesis 23 24 26 26 Participants Study Recruitment Strategy Procedure Components of Cognitive Training Intervention Neuropsychological Primary Outcome Measures 26 26 26 27 28 30 Method iii Results Pre-Intervention Assessment Between Groups Post-Intervention Differences Between Groups Within Group Improvements Magnitude of Improvement Between Groups Training Outcome Measures Discussion Participant Improvements Within Group Intervention Improvements on Trained Tasks Unsuccessful Intervention Outcomes Possible Mechanisms for Post-Intervention Success Clinical Relevance Limitations Conclusions Reference List 35 36 36 37 37 38 40 41 42 43 44 50 51 52 69 iv List of Tables Table 1. Inclusion Criteria 54 Table 2. Exclusion Criteria 55 Table 3. Frequency Distribution for Intervention and Control Group on Stroke 56 Characteristics Table 4. Pre-treatment Comparability of the Intervention and Control Group 57 Table 5. Post-treatment Outcome Measure Between Groups 58 Table 6. Post-Treatment Cognitive Changes Within the Intervention Group 59 Table 7. Post-Treatment Cognitive Changes Within the Control Group 60 Table 8. Improvement Scores for Test in which Both Groups Showed Improvements 61 v List of Figures Figure 1. Study Participant Flow Chart of Enrollment and Randomization 62 Figure 2. Comparing Neuropsychological Changes Between the Groups from 63 Pre-intervention to Post-intervention Figure 3. Post-intervention Differences Between the Groups in Neuropsychological 64 Domains Figure 4. Comparing Magnitude of Neuropsychological Change Between Groups 65 from Pre-intervention to Post-intervention Figure 5. Improvements in Pac-Man High Score from Initial Weeks to Final Weeks 66 of Training Figure 6. Improvements in Pac-Man Duration of Play from Initial Weeks to Final 67 Weeks of Training Figure 7. Improvement in Block Design Duration of time from Initial Weeks to Final 68 Weeks vi List of Appendices Appendix Study Homework Booklet Acknowledgements I would like to express my appreciation to a number of people who enriched this experience in several ways. First and foremost, I am sincerely grateful to Dr. William Tippett whose active supervision made this research possible. Greatest thanks to my family and partner, whose love and support I drew from on a daily basis. I would also like to give warm regards to my committee members for their time and insightful comments on this thesis. Special thanks to the staff at UHNBC and to the patients and caregivers who participated in this project. Lastly, I offer gratitude to the research assistants who lent a hand throughout the duration of this project. viii Introduction Strokes lead to negative effects on brain structure and cognitive function (Gorelick, 2003). The window of opportunity for intervening in some of these effects is time sensitive, meaning that the longer a stroke goes untreated, the greater the chance of permanent neurologic and cognitive damage (Cifu & Stewart, 1999; Feigenson, McDowell, Meese, McCarthy, & Greenberg, 1977; Hayes & Carroll, 1986; Ottenbacher & Jannell, 1993; Schallert, Fleming, & Woodlee, 2003). One of the major risk factors for stroke is experiencing a previous one. An ischemic stroke occurs when there is low blood flow to a core region which eventually infarcts, and this core is surrounded by an area of moderate blood flow, called the ischemic penumbra (Astrup, Siesjo, & Symon, 1981). The ischemic penumbra is at very high risk of infarction and thus secondary stroke is common (Lyden et al., 2005). Generally, individuals who have experienced a stroke, and those with cardiovascular risk factors (such as hypertension), are in the highest risk category for recurrent stroke episodes, and are most likely to benefit from effective therapy (Gorelick, 2003). Furthermore, secondary strokes often have a higher rate of death and disability because the areas of the brain already compromised by the first stroke are no longer as resilient (Gorelick, 2003; Teasell, Bayona, Salter, Hellings, & Bitensky, 2006). Medical and lifestyle strategies to combat the ravaging effects of stroke have been thoroughly investigated. Research recommends avoidance of risk factors such as smoking (Nilsson et al., 2009), heavy alcohol use (Daniel & Bereczki, 2004), and proper management of medical risk factors such as hypertension (Barnett, 2002), diabetes (Najarian et al., 2006) and hypercholesterolemia (Uchiyama et al., 2009). It is also well established that physical exercise (Pang, Eng, Dawson, & Gylfadottir, 2006), stress reduction (Stead et al., 2008), and 1 proper nutrition are additional factors known to reduce damage caused by stroke or to contribute to the prevention of a primary stroke (Gorelick, 2003). The concept that stroke related repercussions are time sensitive does not apply to physical recovery only, but also applies to cognitive recovery (Sachdev, Brodaty, Valenzuela, Lorentz, & Koschera, 2004). Cognitive intervention, however, has not been a primary focus of attention. There is growing interest in the potential for behavioural interventions, such as mental activity, to improve cognitive function in vulnerable populations. One such area that is yet to be investigated is the use of cognitive training as an intervention tool to improve cognition post-stroke. Cognition is defined as the capacity for and expression of knowledge. It is demonstrated when an individual can acquire and retain relevant information in such a way that it can be applied in appropriate situations. Given both the relevance and prevalence of cognitive impairment post-stroke, a need exists to investigate the prospect of a cognitive training program designed for improving cognitive performance post-stroke. Currently no standard cognitive treatment is recognized or available for post-stroke individuals to engage in during their recovery phase. Societal Burden Associated with Stroke Stroke is the third leading cause of death in Canada. More than 50,000 strokes occur annually and many victims are left with significant cognitive impairments and physical disability (Teasell et al., 2006). Vascular cognitive impairment (VCI) affects up to two thirds of stroke survivors (Madureira, Canhao, Guerreiro, & Ferro, 2000; Ballard, Rowan, Stephens, Kalaria, & Kenny, 2003) and represents a substantial public health burden, with the direct per-patient lifetime costs estimated to be approximately $10,000 for persons with mild disease and $27,500 for persons with severe disease (Claesson, Linden, Skoog, & 2 Blomstrand, 2005; Heart and Stroke Foundation of BC and Yukon, 2000). Stroke related deficits are also associated with indirect healthcare costs, impaired daily functional abilities (Di et al., 2000; MacNeill & Lichtenberg, 1998), hospitalization and cognitive impairment (Arfken, Lichtenberg, & Tancer, 1999; Lin et al., 2003; Tatemichi et al., 1994) and reduced life expectancy (Cederfeldt, Gosman-Hedstrom, Perez, Savborg, & Tarkowski, 2010; Claesson et al., 2005; Desmond et al., 2000; Hinkle, 2006; Prencipe et al., 1997; Ruchinskas & Curyto, 2003; Wolfson et al., 2001; Zinn et al., 2004). Furthermore, an estimated one quarter to one third of stroke patients will meet dementia criteria within 3 months of experiencing stroke (Leys, Henon, Mackowiak-Cordoliani, & Pasquier, 2005; Tatemichi et al., 1990). Evidence indicates that a stroke survivor has a 20% chance of having another stroke within 2 years and this rate doubles every 10 years after the age of 65 (Heart Disease and Stroke in Canada, 2006). Stroke numbers are expected to rise in 2011 when the first baby-boomers will be age 65 (Heart Disease and Stroke in Canada, 2006; Teasell et al., 2006). The implication of an expected rise in stroke is significant in light of the burden that is associated with stroke related disability. Secondary Stroke Overview There are more than 300,000 stroke survivors in Canada and a major goal of therapy for patients who have experienced stroke is to prevent recurrent stroke. Canadian secondary stroke prevention focuses on improving access to stroke specialists in order to manage vascular risk factors, improve physical mobility and promote public awareness on the importance of healthy living (Tatemichi et al., 1990). Indeed, evidence indicates that patients receiving professional advice on healthy living have a greater chance of preventing further complications (Greenlund, Giles, Keenan, Croft, & Mensah, 2002). One of the most 3 widespread practices by physicians for secondary stroke prevention is the use of agents that act to prevent blood occlusion [e.g., aspirin and angiotensin converting enzyme (ACE) inhibitors]. Research on the effectiveness of blood pressure medication on the improvement of cognition among stroke survivors has shown that this treatment is not effective in preventing or improving cognitive decline in this population (Feigin, Ratnasabapathy, & Anderson, 2005). Furthermore, there is evidence that pharmaceutical methods can sometimes impede cognitive functioning. For example, using antihypertensives can affect attention and executive functions and can be linked with ongoing neuropathological changes (Di et al., 2000; Hadjiev & Mineva, 2008). This cognitive damage following pharmaceutical prevention methods is problematic because stroke is already a major risk factor for dementia and can expedite the conversion of existing cognitive impairment to dementia (Gamaldo et al., 2006; Pendlebury & Rothwell, 2009). It has been noted that shortly after a first-ever stroke, 10% of people may develop dementia (Teasell et al., 2006) and recurrent stroke can result in dementia in one-third of patients (Pendlebury & Rothwell, 2009). As researchers, the challenge is to target this at-risk population in the safest way possible. Stroke Best Care Practice Best Model of Stroke Care Units Rehabilitation provides a means to alleviate the burden of disability associated with stroke. However, given that rehabilitation is so resource-demanding, it is important that it be executed in the most efficient and cost effective manner, in accordance with best scientific and research based evidence (Teasell et al., 2006). Specialized stroke rehabilitation units (which include both rehabilitative and acute services) produce markedly better outcomes when compared with less organized stroke units, 4 such as mixed rehabilitation or general medicine wards (Govan et al., 2007; Stroke Unit Trialists' Collaboration, 2001). Evaluations looking at differences between dedicated stroke units and less organized stroke teams have elucidated some of the factors that contribute to the advantages of specialized units. Within seven days of admission, patients on specialized stroke units are assessed by social and occupational therapists and their medical needs are more closely monitored compared to patients on general units (Evans et al., 2001). Other studies have noted that this level of attentive care does not cease at 7 days, but persists throughout the first four weeks of stroke, which is considered the most critical rehabilitation period by physicians and researchers (Evans et al., 2001; Teasell et al., 2006). For example, unlike general stroke units, specialized stroke units provide patients with an evaluation of rehabilitation goals and long term discharge plans within 4 weeks of admission (Evans et al., 2001; Indredavik, Bakke, Slordahl, Rokseth, & Haheim, 1999). Early monitoring is imperative because complications are known to be common following stroke. Approximately 82% of stroke patients experience complications, the most common complications being falls and urinary tract infections (Sorbello et al., 2009). One of the elements of stoke unit care that has been associated with improved outcomes is the prevention of these complications. Indredavik and colleagues (2008) followed 489 acute stroke patients in a specialized stroke unit and found a significant reduction in the number and severity of complications compared to patients in loose stroke settings. After the critical rehabilitation period, there are also benefits to specialized stroke units in terms of rehabilitative services. In a retrospective study Ang and collegues (2003) reported that acute patients of a specialized stroke unit benefited by having shorter lengths of hospitalization and better overall functional abilities. The authors speculated that the main reason for the improved outcome was due to the seamless 5 nature of specialized stroke care. For example, patients did not have to wait for a bed to become available or be physically transferred before they could begin intensive therapy (Ang, Chan, Heng, & Shen, 2003). Finally, in the long run, patients from specialized stroke units are more likely to be adequately referred to follow-up clinics and more likely be put on anticoagulation therapy at discharge (Barber, Langhorne, Rumley, Lowe, & Stott, 2004). This is in accordance with best practice evidence showing that optimal prognosis is achieved when there is an on-going process in place in which patients are referred to secondary stroke prevention clinics at discharge (Sulch & Kalra, 2000). Best Model for Timing of Stroke Rehabilitation The results of several studies have suggested that soon after stroke, rehabilitation should be initiated in order to maximize results (Feigenson et al., 1977; Gagnon, Nadeau, & Tam, 2006; Hayes & Carroll, 1986; Paolucci et al., 2000). Early admission to stroke rehabilitation is strongly correlated with improved functional outcomes, which is demonstrated in both individual studies and meta-analysis. In a meta-analysis examining the potential benefits of early intervention, Cifu and Stewart (1999) concluded that the literature supports an intervention timeframe between 3 to 30 days post stroke for optimal functional outcomes (Cifu & Stewart, 1999). Recently, Maulden et al. (2005) has confirmed the necessity of early intervention, reporting that delaying the onset of rehabilitation was associated with lower functional independence measure (FIM) scores and increased hospitalization for patients with both moderate and severe strokes (Maulden, Gassaway, Horn, Smout, & DeJong, 2005). The interval between stroke onset and admission to rehabilitation is so time sensitive that delaying rehabilitation even for a few days is a significant predictor of lower discharge FIM scores and longer hospitalization. In another 6 meta-analysis including 258 stroke patients, Salter et al (2006) found that time between a stroke episode and admission to rehabilitation predicted the achievement of rehabilitation potential (Salter et al., 2006). Most recently, Langhorne et al. (2010) examined the effects of early mobilization on medical outcomes. They found that medical complications were lower among subjects in the early mobilization group compared to the longer onset rehabilitation group (Langhorne et al., 2010). Best Model for Intensity of Therapy When outlining the elements that contribute to optimal functional outcomes seen in specialized stroke rehabilitation, the intensity of rehabilitation therapies is often mentioned. Intensity is generally taken to mean the number of minutes per day of therapy or the number of hours of consecutive therapy (Teasell et al., 2006). Generally, an intense rehabilitation program is defined as 21 or more hours of therapy per week (Teasell & Foley, 2008), whereas 4-8 hours per week would be considered a non-intensive program (Page, 2003). Neuroimaging evidence suggests that increased intensity of rehabilitation results in greater activation in various cortical areas, specifically the parietal region (Kalra & Langhorne, 2007). The results of 19 randomized controlled studies show that increasing the intensity of physiotherapy results in both significant reduction of impairments and improvement in activities of daily living (Askim et al., 2010; Di et al., 2003; Feys et al., 1998; Kwakkel, Wagenaar, Twisk, Lankhorst, & Koetsier, 1999; Kwakkel, Kollen, & Wagenaar, 2002; Langhammer, Lindmark, & Stanghelle, 2007; Langhammer, Stanghelle, & Lindmark, 2008; Langhammer, Stanghelle, & Lindmark, 2009; Lincoln, Parry, & Vass, 1999; Logan, Ahern, Gladman, & Lincoln, 1997; Parry, Lincoln, & Vass, 1999; Partridge et al., 2000; Pohl, Mehrholz, Ritschel, & Ruckriem, 2002; Pohl et al., 2007; Richards et al., 1993; Slade, 7 Tennant, & Chamberlain, 2002; Sunderland et al., 1992; Sunderland et al., 1994; Werner & Kessler, 1996). The benefit of augmenting therapy intensity has also been evaluated by Kwakkel et al. (2004) in a 20 study meta-analysis that included many interventions: occupational, physiotherapy, leisure therapy, home care and sensorimotor training (Kwakkel et al., 2004). Regardless of therapy type, they found that intensity had a significant effect on activities of daily living and functional outcome measures. Intensity of therapy has also been linked to length of hospitalization. In a large cohort of stroke survivors (n = 23,824), Wodchis et al. (2005) found that intensity of rehabilitation was positively associated with expedited discharge in patients with an uncertain prognosis on admission (Wodchis et al., 2005). This association was confirmed in a recent study by Jette et al. (2005) who found higher intensity of therapy was associated with shorter hospitalization and higher likelihood of functional independence and mobility (Jette, Warren, & Wirtalla, 2005). Importantly, the benefit of increasing the intensity of therapy is maintained beyond the treatment phase. The results of a meta-analysis which included 10 studies demonstrated that increased therapy intensity had a positive effect on activities of daily living as measured by functional measures (i.e., Barthel Index) and improvements were maintained over a 6-month period (Galvin, Murphy, Cusack, & Stokes, 2008). British Columbia's Stroke Strategy The blueprint for British Columbia's Stroke Rehabilitation Service is composed of several elements. Rehabilitation assessment is one of these elements (Stroke Report British Columbia, 2000). It is suggested that within 48 hours of stroke, professionals should use standardized assessment tools to evaluate the patient's impairment and determine if/when the patient will be ready to begin post-acute rehabilitation. The cornerstone of post-acute 8 rehabilitation is typically restricted to physiotherapy, occupational and speech therapy. Once the stroke survivor is ready to begin rehabilitation, the patient and their family work with the unit to determine personal rehabilitation needs and develop a care plan. Recently, the Stroke Strategy's Rehabilitation Report confirmed that stroke patients in British Columbia are unable to access consistent healthcare, as constrained by resource availability. BC's limited access to rehabilitation services has meant that some stroke survivors (including those in northern regions such as Prince George) may not have the opportunity to participate in a comprehensive stroke rehabilitation program and consequently may never reach their full functional potential (Stroke Report British Columbia, 2000). It is becoming increasingly clear that rural populations have a great need for specialty physician services. Studies have found that physicians may be reluctant to work in rural areas due to the nature of practice characteristics such as long hours, lengthy on-call schedules (Kazanjian & Pagliccia N, 1996) and educational isolation (Rourke et al., 2005). It is particularly challenging for small centres to identify and create stroke units and to provide ongoing acute care. For example, University Hospital of Northern British Columbia (UHNBC) currently offers no specialized stroke care unit or specialized secondary stroke prevention clinics in which to discharge patients for follow-up care. Literature Review on Visuospatial/Visuomotor Cognitive Training Despite the prevailing incidence of cognitive deficits post stroke, rehabilitation of stroke is heavily focused on assisting physical function. In exceptional cases in which cognitive training is incorporated into rehabilitation, it is limited to very specific cognitive tasks. Here we review the strides that have been made with regards to research on visuospatial cognitive training. Visuospatial/visuomotor (VS/VM) abilities are those related 9 to understanding and conceptualizing visual representations and spatial relationships and the ability to use this information to manually perform a task. First, a definition of how the efficacy of a given training program is determined will be provided. This will be followed by an overview of specific research studies that comprehensively demonstrate what is currently known about visuospatial cognitive training from basic to more complex remediation. Defining the Evaluation Process of Cognitive Intervention An ideal way to evaluate cognitive training intervention is by a randomized controlled trial. A randomized control trial is an experimental design where participants are randomly assigned to a treatment group (experimental therapy) or a control group (placebo or standard therapy) and then a comparison is made. In clinical practice, "pure" no-treatment control conditions are impossible and unethical to establish. Therefore all patients regardless of group assignment continue to receive standard care. The key of interventional studies, then, is to look at pre/post interventional differences to determine whether the intervention offers specific benefits above and beyond standard treatment. Therefore, the success of a treatment is verified by comparing its benefits with those of the "best available" treatment (Cicerone, 2005). The best available treatment for post-stroke recovery is the combined application of physiotherapy, occupational and speech therapy, along with any individualized recommendations dictated by clinical experience and determined by the patient's clinical care team (Lincoln, Whiting, Cockburn, & Bhavnani, 1985). With the use of exercise equipment and aqua-fitness to train the affected limb, these conventional therapies are primarily concerned with reducing impairments through compensatory mechanisms, and can be classified as a "bottom-up" approach. This approach can be contrasted to the underlying philosophy behind cognitive training in which the aim is to reverse disability by promoting 10 neural activity in a "top down" manner, thereby directly treating the effected organ: the brain. Finally, most studies of cognitive rehabilitation have relied on neuropsychological outcome measures to evaluate the success of treatment. Thus, comparison to baseline scores measured before treatment is an effective way to evaluate improvement. Remediation of Neglect and Visuospatial/Visuomotor Deficits VS/VM impairments are a significant cause of disability after stroke. For example, there is well-documented evidence that VS/VM impairments are a common consequence of right hemisphere stroke (Byrd, Touradji, Tang, & Manly, 2004; Feldman et al., 2001; Halligan, Burn, Marshall, & Wade, 1992; Huang & Wang, 2008; Lowery, Ragland, Gur, Gur, & , 2004; Weintraub & Mesulam, 1988; Wilson, Cockburn, & Halligan, 1987; Lowery et al., 2004; Tippett & Black, 2008; Lowery et al., 2004). VS/VM impairments typically cooccur with neglect (decreased awareness) for one side of the visual field, causing a patient to act as if that side of sensory space does not exist. Even if patients have moderate or good neurological recovery, neglect and VS/VM cognitive impairments account for the most persistent and prominent consequence of right hemisphere brain injury (Cicerone, 2005). Furthermore, the presence of unilateral neglect in subjects with right hemisphere stroke is associated with greater functional disability and prolonged hospitalization (Katz, HartmanMaeir, Ring, & Soroker, 1999). For the remediation of neglect, the following review will emphasize research studies that have focused on the improvement of basic abilities and behaviours such as visual scanning (exercises that promote awareness of the neglected hemisphere). In terms of VS/VM remediation, the following review will focus on studies that have addressed the training of complex and high-level skills such as reading and writing that depend on intact spatial relationships (Cicerone et al., 2000; Cicerone, 2005). 11 12 Training Effectiveness of Visual Scanning Substantial efforts have gone into devising techniques for the rehabilitation of neglect. Scanning training is classically the most popular rehabilitative approach (Gordon et al., 1985; Weinberg et al., 1977). This technique relies on the observation that the majority of problems encountered by neglect patients arise from a defective visual exploration strategy (Smania, Bazoli, Piva, & Guidetti, 1997). Indeed, these patients demonstrate a reluctance to explore the left hemispace and rather begin their scan from the right hemispace (Cheti, Leblanc, & Lhermitte, 1973), moving the gaze vertically rather than horizontally (Chatterjee, Mennemeier, & Heilman, 1992). Scanning training generally is composed of exercises that aim at gradually amplifying the horizontal extension of the patient's visual scanning habits, repairing their visual exploration tendencies. The following describes studies that have focused on the efficacy of visual scanning training for the remediation of unilateral neglect caused by right hemisphere damage. Weinberg and colleagues (1977) compared standard rehabilitation with an intervention that trained stroke patients to compensate for impaired scanning habits. People in the standard rehabilitation sample (n =32) and the experimental group (n = 25) were at least 4 weeks post insult. The experimental treatment group received 20 hours of training in which visual material was incrementally used to enhance left-sided scanning. This training required patients to acknowledge the neglected field by searching for stimuli presented to the left visual field. The treatment group significantly improved on both specific scanning measures and academic reading tests that were taken to rely on intact visual scanning (Weinberg et al., 1977). Variations of this procedure and extensions of the design were explored by Young and colleagues (1983). This research also compared a standard 13 rehabilitation control group (n = 14) with an experimental training group (n = 13) with the objective of confirming the usefulness of scanning training to remediate neglect caused by right hemisphere damage. The trained patients were required to complete a number of visual cancellation tasks for 20 hours over a 4 week period. The experimental group significantly improved on academic measures of reading and writing compared to controls (Young, Collins, & Hren, 1983). In an effort to uncover new benefits of scanning training, Wiart and colleagues (1997) used functional outcome measures (i.e., Functional Independence Measure) to demonstrate that stroke patients who received visual scanning training (n = 11) not only significantly reduced neglect but also improved on activities of daily living compared with those who received traditional rehabilitation (n = 11) (Wiart et al., 1997). Improvement in functional abilities also has significant implications as it relates to the potential for reducing health care costs. Indeed, Kalra and colleagues (1997) compared standard stroke rehabilitation to an intervention group that involved scanning training to demonstrate that neglect patients who received the intervention produced significant improvements on spatial exploration and had significantly shorter hospitalization compared to controls (Kalra, Perez, Gupta, & Wittink, 1997). The results of these studies indicate that training in visual scanning is required to reduce functional impairments in activities such as reading and driving (Klavora et al., 1995). Furthermore, many other comparable studies (Butter & Kirsch, 1992; Carter, Howard, & O'Neil, 1983; Gordon et al., 1985; Gouvier, Cottam, Webster, Beissel, & Wofford, 1984; Kalra et al., 1997; Kerkhoff, Munssinger, Haaf, Eberlestrauss, & Stogerer, 1992; Kerkhoff, Munbinger, Eberle-Strauss, & Stogerer, 1992; Lincoln et al., 1985; Neistadt, 1992; Pantano et al., 1992; Pizzamiglio et al., 1992; Pommeranke & Markowitsch, 1989; Robertson, Tegner, Tham, Lo, & Nimmo-Smith, 1995; Soderback, Bengtsson, Ginsburg, & 14 Ekholm, 1992; Taylor, Schaeffer, Blumenthal, & Grisell, 1971; Weinberg et al., 1979; Weinberg, Piasetsky, Diller, & Gordon, 1982; Wiart et al., 1997; Young et al., 1983), reaffirm the superiority of visual scanning training to conventional physical therapies alone. Moreover, the superiority of scanning training to conventional rehabilitation is evident even in persons without neglect and extends to those with a left hemispheric stroke. For example, five studies (Carter et al., 1983; Lincoln et al., 1985; Neistadt, 1992; Taylor et al., 1971; Weinberg et al., 1982) compared the effectiveness of visual scanning training with conventional rehabilitation therapies for patients without evidence of unilateral neglect and included a mix of right and left hemisphere stroke. The subjects who received visual scanning training had significantly greater improvement after 3 to 4 weeks of treatment than did subjects who received conventional stroke rehabilitation. Furthermore, scanning training appears to be beneficial even in chronic (i.e., several years post-stroke) patients with neglect, and this improvement applies to daily life conditions. For example, research conducted by Dam et al (1993) and Paolucci (1996) has demonstrated that chronic neglect stroke patients (including both left and right hemisphere stroke) who were given scanning treatment achieved better motor and functional recovery than patients who underwent only motor rehabilitation (Dam et al., 1993; Paolucci et al., 2000). Training in visual scanning is so fundamental that the National Institutes of Health considers it a standard for remediation of neglect (Cicerone, 2005) and the aformentioned studies suggest that it should be implemented after right or left hemisphere stroke and for both acute or chronic cases. Training Effectiveness of Complex Visuospatial Skills For persons with visuospatial deficits associated with right hemisphere stroke, additional training on more complex visuospatial tasks appears to enhance the benefits of 15 treatment and facilitate generalization to other visuospatial, academic, and functional activities (e.g., reading, writing, walking). Studies focused exclusively on training complex visuospatial skills are sparse and relatively dated. The following is a review of studies that have addressed the remediation of visuospatial deficits. Weinberg and colleagues (1979) assessed the training effects of complex visuospatial skills for 50 subjects with right hemisphere stroke. The 30 subjects in the experimental condition received 20 hours of training in reading, writing and calculation that depend on intact visuospatial organization in addition to visual scanning training. The 20 subjects in the control condition received an equivalent amount of standard rehabilitation. The subjects in the intervention group significantly improved on visuospatial functional and academic tasks relative to the control group. The benefits were most apparent among subjects with more severe visuospatial impairments. The authors proposed that incorporating multiple treatment levels into training (scanning plus visuospatial activities) produced more benefits and greater generalized improvements than a single treatment program (i.e., scanning) (Weinberg et al., 1979). Weinberg and colleagues (1982) continued to explore the usefulness of visuospatial training by providing training designed to establish a systematic strategy for organizing visual material (e.g., tips for picture copying). The study was for right hemisphere stroke patients with visuospatial deficits without visual neglect, most of whom were more than 3 months post-stroke. Compared with conventional rehabilitation, the experimental treatment produced benefits on measures of visual analysis (e.g., matching faces) and organization (e.g., picture completion) (Weinberg et al., 1982). The claim of the effectiveness of systematic treatment directed at multiple levels of visuospatial impairment was further examined by Gordon et al. (1985). A comprehensive program of treatment for visuospatial 16 disturbances associated with right hemisphere stroke was developed by combining 3 types of visuospatial techniques: (1) basic visual scanning, (2) somatosensory awareness and size estimation, and (3) complex visuoperceptual organization (e.g., picture assembly). Among 77 acute right hemisphere stroke subjects receiving rehabilitation, 48 received the experimental treatment and 29 received conventional rehabilitation. At rehabilitation discharge, the experimental group showed greater improvement than the control group in all 3 areas of visuospatial functioning. In addition, functional gains were shown by increased leisure reading and increased performance in activities of daily living (Gordon et al., 1985). These studies lend support that stroke patients on the whole may benefit from systematic training of visuospatial skills as part of their acute rehabilitation. Comparisons across the aforementioned studies producing positive effects in visuospatial remediation and a few studies finding no effect (Edmans et al., 2009; Robertson, Gray, Pentland, & Waite, 1990; Lincoln et al., 1985) suggest that effective training needs to be relatively intense (i.e., daily) (Kwakkel, Wagenaar, Koelman, Lankhorst, & Koetsier, 1997; Kwakkel et al., 1999; Langhorne, Wagenaar, & Partridge, 1996; Tangeman, Banaitis, & Williams, 1990; Taub et al., 1993; Teasell et al., 2006; Wolf, LeCraw, Barton, & Jann, 1989). Furthermore, the amount of improvement is associated with the intensity of rehabilitation (Gladstone, Black, & Hakim, 2002; Langhorne et al., 1996; Nugent, Schurr, & Adams, 1994; Smith et al., 1981; Teasell et al., 2006). A summation of all this research indicates that effective treatment should involve 20 individual 1-hour sessions delivered on separate days over a period of 4 weeks. Furthermore, the effects of short and intensive treatment appear to be maintained in the long term (i.e., up to 1 year) (Wiart et al., 1997; Diller & Gordon, 1981; Pizzamiglio et al., 1992). 17 Video-gaming Training Effectiveness The use of video-gaming technology is emerging as a novel technique in rehabilitation for stroke patients. Video games maintain the spirit of training (i.e., progressive level of difficulty as performance improves) while offering enriched environments that may maximize brain plasticity after stroke (Adamovich et al., 2004; Levin, 2011; Saposnik & Levin, 2011). Among the existing studies that have utilized gaming systems with stroke populations, the purpose has been to improve motor deficits with no focus on cognitive outcome measures. However, the overriding consensus from these studies has been that gaming systems keep patients motivated and engaged for long periods of time to allow the brain to make full use of its ability to recuperate (Adamovich et al., 2004; Levin, Knaut, Magdalon, & Subramanian, 2009; Saposnik et al., 2010; Saposnik & Levin, 2011). In a recent randomized controlled trial, Saposnik and colleagues (2010) demonstrated that the use of Wii training resulted in significantly better upper-body movement and improvement of activities of daily living in 20 acute stroke patients compared to patients who received only standard rehabilitation (Saposnik et al., 2010). Levin and colleagues (2010) have confirmed these findings in a more elaborate study that delineated the specific benefits of 2-dimensional (2D) and 3-dimensional (3D) virtual systems compared to conventional rehabilitation protocols. Both 2D and 3D treatment was shown to be superior to conventional rehabilitation. Arm mobility was most remarkable in patients treated with the 3D virtual reality system, followed by those in the more modest 2D game system. Furthermore, improvement in upper extremity function using videogames has also been demonstrated in patients who had spatial neglect (Katz et al., 1999; Weiss, Bialik, & Kizony, 2003). Analogous studies examining the benefits of gaming systems have supported their efficacy even in chronic stroke patients. 18 Adamovich and collegues (2010) trained 24 chronic stroke patients on a video game for 22 hours over a two-week period. The trained group significantly improved on reaction and movement time compared to controls (Adamovich et al., 2004). Mapping of the brain using functional magnetic resonance imaging (fMRI) suggested that this recovery may be due to increased functional connections between motor and sensory regions (Adamovich, 2010). Although there is limited evidence available on the effectiveness of video gaming in the context of cognitive rehabilitation of stroke, research in normal aging has already demonstrated that gaming has positive outcomes on visuospatial skills (Green & Bavelier, 2003), reaction time (Dustman, Emmerson, Steinhaus, Shearer, & Dustman, 1992; Gopher, Weil, & Bareket, 1994), increased hand-eye coordination (Drew & Waters, 1986), mental rotation and visual attention (Dye, Green, & Bavelier, 2009; Green & Bavelier, 2003). To examine the influence of video game playing on regional cerebral blood volume, Hoshi and Tamura (1997) measured cerebral hemoglobin concentrations using near-infrared spectroscopy in six older adults. After only 14 seconds of game playing, they found a significant increase in fronto-parietal haemoglobin levels (Hoshi & Tamura, 1997). In a study using positron emission tomography (PET), Haier et al. (1992) observed regional glucose metabolic changes in adults who engaged in a VS/VM task. In approximately 4 weeks of daily practice, cortical glucose metabolism significantly decreased despite a 7-fold increase in performance (Haier et al., 1992). These authors suggested that the use of video game training worked to strengthen cortical circuits, resulting in decreased use of extraneous or inefficient brain resources, thus liberating the brain to function more efficiently. Video­ games may also have an influence on increasing levels of cerebral oxygenation by regulating physiologic parameters such as systemic arterial pressure. For example, Segal et al. (1991) 19 reported that playing video games significantly increased systolic and diastolic blood pressure, heart rate, and oxygen consumption, which also facilitated an increase in simultaneous cerebral hemoglobin changes in adults in the frontoparietal regions (Segal & Dietz, 1991). Finally, using PET Koepp et al. (2008) has shown that engaging in videogames produces a significant increase in brain dopamine levels compared to controls (Koepp et al., 1998; Kopp, Rosser, & Wessel, 2008). This surge in dopamine is thought to play an important role in learning following visuospatial training. On the forefront of this research are Bao and colleagues (2001) who argue that the presence of dopamine is not only apparent, but is necessary for fast and widespread visuospatial learning (Bao, Chan, & Merzenich, 2001). For many brain injuries the rehabilitation process is very taxing and there is a challenge in finding appealing and motivating intervention tools that will facilitate this process. Videogame training may answer this challenge by providing the opportunity for active learning while still permitting strict experimental control over stimulus delivery, as well as the opportunity to individualize treatment needs while incrementally increasing the task complexity (Rizzo, 2003; Schultheis & Rizzo, 2001). Visual Imagery Training Effectiveness Action observation can engage motor cortical activity in the absence of overt movement. Such cortical activity is regulated by neurons, often noted as mirror neurons, which fire when individuals watch others performing actions (Kandel, Schwartz, & Jessell, 2000). Recent studies have also shown that mirror neuron training performs an important role in accelerating recovery of arm and leg function post-stroke by facilitating learning of complex actions and through internal rehearsal of actions (Altschuler et al., 1999; Buccino, 20 Solodkin, & Small, 2006). Training stroke patients to imagine moving their affected arm (e.g., motor imagery) has the potential to promote recovery of extremity function by promoting neuroplasticity. For example, several fMRI studies of observation learning have shown that watching someone else's action is associated with activation in the same parietal and premotor regions that are used when actually producing the action (Decety et al., 1997; Grezes & Costes, 1998; Grezes, Costes, & Decety, 1999). Two important findings from neurophysiological studies provide evidence for neuroplasticity. First, recovery of hand function after stroke is accompanied by a particular compensatory pattern of activity in the motor cortex (Dijkerman, Ietswaart, Johnston, & MacWalter, 2004). Second, imagining making hand movements simulates the same compensatory pattern of brain activity that is seen accompanying actual recovery of hand function (Decety & Ingvar, 1990; Weiller, 1995). Direct evidence for the efficacy of imagery training comes from a pilot study by Page and colleagues (2000). The researchers gave chronic stroke patients (n = 16) a series of scripts that described a variety of motor movements and required them to mentally rehearse the scripts 3 hours/week for six weeks. At study completion, they found a significant improvement in arm function in the trained stroke patients compared to controls who received only conventional rehabilitation. Improvements also generalized to functional measurements that were not directly trained but relied on similar brain regions (Page, 2000). In a later study, Page et al. (2001) replicated these results on a sample of sub-acute (1 year post-insult) stroke cases (n = 13) (Page, Levine, Sisto, & Johnston, 2001). More support for the efficacy of imagery training has also been provided by Dijkerman (2004) who compared each of two different types of imagery groups to a control group. Chronic stroke patients in the experimental group (n = 10) who mentally rehearsed a 21 motor task were compared to a non-motor imagery group (n = 5), and a control group that was not engaged in mental rehearsal (n = 5) (Dijkerman et al., 2004). On a daily basis, the motor imagery group was required to practice imagining moving tokens with their affected arm. The non-motor imagery group rehearsed visual imagery of previously seen pictures. All three patient groups improved on the motor tasks. However, improvement was greater for the motor imagery group, followed by non-motor imagery and then the control group. Beyond physical remediation, there is also some precedent for the use of visual imagery to alleviate neglect in stroke patients. Niemeier (1998) compared standard rehabilitation with a novel technique to train acute stroke patients to imagine their eyes as beams of a lighthouse, sweeping the horizon from left to right. After presenting a picture of a lighthouse, the patients were required to use this imagery while performing functional activities that require integrative VS/VM abilities such as dressing and eating. The experimental (n = 16) and control groups (n = 15) were approximately 2 months post-insult and were both composed of left and right hemisphere stroke patients. Post-treatment results showed that the experimental group participants were significantly better than the controls in performing tasks related to neglect (i.e., Mesulam Cancellation) and visual attention (i.e., Facility Rating Scale) (Niemeier, 1998). In a more elaborate study by Niemeier and colleagues (2000), stroke patients were trained to use a variety of visual and motor imagery techniques to remediate neglect. Visual imagery training required participants to explain a familiar path by reporting the location of the buildings, roads, and other reference points (e.g., signs, advertising posters). At post-treatment, the treatment group performed significantly better on functional tasks (e.g., walking and wheelchair route-finding) (Niemeier, 2000). Additional research conducted by Smania and colleagues (1997) utilized 22 motor imagery to train participants to imagine the affected arm positioned in one of several given postures and then to describe the relative position of the contralateral arm. The study delivered forty sessions, each lasting 50 minutes. Improvements in performance, which persisted at 6 month follow-up, were reported on a range of neuropsychological (e.g., Letter H Cancellation) and functional (e.g., reading) measures (Smania et al., 1997). Using a slightly different research methodology, McCarthy and colleagues (2002) designed a study to investigate whether imagined limb activation reduced the extent of neglect in two single case studies. The study implemented an ABBABBA (counterbalancing) design where patients were required to imagine making movements of the left arm during the intervention conditions. Neglect was measured using neuropsychological measures. Performance during intervention conditions were compared to baseline conditions. The results showed that imagined activation of the left arm significantly reduced the symptoms of left-sided neglect (McCarthy, Beaumont, Thompson, & Pringle, 2002). Because inputs to the mirror neuron system are visual and auditory, this bypassing strategy may offer an alternate access to motor networks independent of the affected primary motor cortex. Accordingly, motor imagery-based intervention may prove particularly beneficial in hemiplegic patients because it offers opportunities to directly activate cortical areas representing a paralyzed limb which would not be activated otherwise (Sharma, Pomeroy, & Baron, 2006). Finally, because the imitation network is engrained at a young age and hardwired from past-life experiences, this form of training is presumed to come naturally to patients. 23 Visuospatial/Visuomotor Cognitive Intervention Program Cognitive Training Project Rationale Nation-wide evidence suggests that within a few months of discharge, stroke survivors often return to clinics or primary care physicians with complaints of cognitive impairment (Cicerone, 2005). It has been reported that compared to healthy adults, stroke survivors have up to a 10-fold relative risk of developing dementia, and this risk persists for at least 3 to 5 years (Kokmen, Whisnant, O'Fallon, Chu, & Beard, 1996; Savva & Stephan, 2010; Ukraintseva, Sloan, Arbeev, & Yashin, 2006). Results from the Framingham study showed that over a 10-year span, individuals with a stroke episode had twice the risk for developing dementia compared to healthy age and gender matched controls (Elias et al., 2004; Savva & Stephan, 2010; Ukraintseva et al., 2006). Stroke in relation to cognitive dysfunction poses high risk, particularly in rural regions with limited access to speciality services, and therefore cognitive intervention is a viable target that may help preserve cognitive vitality. To my knowledge, there are currently no published studies examining the efficacy of a comprehensive VS/VM training program to improve post-stroke cognitive recovery, but given the evidence presented I have postulated that it could be a fruitful approach. This idea is based on two well-supported findings. First, decaying brain volumes caused by stroke weaken the brain's line of defence against ischemic attacks, resulting in a cascade of pathological events and cognitive ramifications (Kase et al., 1998). However, the use of cognitive intervention may promote neuroplasticity and may provide additional facilitation of blood flow to the brain, thereby maximizing the brain's defence mechanisms. For example, reperfusion to high risk areas, particularly the ischemic penumbra, may cause the affected neurons to resume functioning thereby improving functional outcomes. The 24 previously mentioned studies in which Hoshi et al. (1997) and Haier et al (1992) observed regional glucose metabolic changes in adults who engaged in VS/VM tasks and videogaming is prime evidence of the potential of increased neuroplasticity and blood flow to the brain. Second, it is possible that parietal lobe stimulation, through the use of a VS/VM training program, may improve global cognitive and day-to-day functioning. Support for this idea comes from Loewnstein et al. (2004) who included a visuomotor speed of processing task and proposed that improved performance on functional tests (e.g., making change for a purchase) was actually a result of the VM training (Loewenstein, Acevedo, Czaja, & Duara, 2004). Furthermore, the previously mentioned studies by Levin (2010) and Saposnik et al. (2010) have demonstrated that videogames improve both mobility and cognitive ability in post-stroke recovery. Collectively, these studies and others have suggested that a network of connections between the parietal and other brain regions are important for VS tasks (Tippett & Black, 2008; Tippett et al., 2009), and that a cognitive training program designed to stimulate VS processes can act to strengthen the network, priming them for other cognitive and functional tasks. It can be postulated that cognitive exercise acts like a buffer to increase the capacity of the brain to endure neuropathological changes. This ability of the 'fitter brain' to adapt to neurological stressors may result from the brain being "flexed" in the learning process (Stern, 2009). Whether a post-stroke program focusing on VS and VM training can flex the brain enough to improve compromised cognitive ability is not yet known. Summary of Project Elements The following is a summary of best practice principles for post stroke cognitive recovery, and was utilized as the structure for this research. New interventional research should strive to address these principles. 25 1. Randomized control trials looking at pre/post interventional differences are the most widespread methodological design to determine whether an intervention offers specific benefits above and beyond standard treatment (Cicerone, 2005). 2. To maximize the efficacy of treatment, training needs to be relatively intense (i.e., daily) (Gladstone et al., 2002; Teasell et al., 2006). 3. Visual scanning training is necessary for the remediation of neglect caused by right hemisphere stroke and its incorporation into conventional therapy is more effective for improving cognition and functional abilities than conventional therapy alone (Wiart et al., 1997). 4. The superiority of scanning training to conventional rehabilitation is evident even in stroke patients without neglect and extends to those with a left hemispheric stroke (Neistadt, 1992). 5. For persons with stroke involving visuospatial deficits, additional training on more complex visuospatial tasks (i.e., treatment designed to establish a systematic strategy for organizing visual material) appears to enhance the benefits of treatment (Gordon et al., 1985). 6. Video gaming has the ability to promote brain plasticity (e.g., cortical reorganization, blood reperfusion) after stroke and has been linked to improvement in physical mobility. Research is absent with regards to its effectiveness in post stroke cognitive recovery (Levin, 2011; Saposnik et al., 2010). 7. Visual imagery of hand movement simulates the same brain region that accompanies actual hand movement and has also been linked to remediation of neglect symptoms (Dijkerman et al., 2004). 26 Objectives The goal of this study was to investigate whether the incorporation of visuospatial/visuomotor (VS/VM) cognitive training to standard stroke therapy is an effective tool for improving acute post-stroke recovery. Hypotheses Brain training that focuses on VS/VM activities effectively improves acute poststroke recovery in that it provides widespread benefits to cognition (e.g., memory, language), function (e.g., activities of daily living) and mood (e.g., depression) that supersedes what is offered by standard therapy alone. Method Participants The performance of nine right-handed primary stroke participants in the experimental group (5 male, 4 female, mean age at stroke 65 ± 9.31) was compared to that of nine righthanded stroke participants in the control group (6 male, 3 female, mean age at stroke 67 ± 7.81). Mean number of years of public education was 9 ± 2.07 for the experimental group and 10 ± 1.45 for the control group. Mean days since stroke was 14.78 ± 2.94 for the experimental group and 16.66 ±4.18 for the control group. Participants were recruited from UHNBC and met the inclusion and exclusion criteria outlined in Tables 1 and 2 respectively. Table 3 presents the frequency distribution for the groups on stroke characteristics as per physician identified. Study Recruitment Strategy Initial screening for participants was obtained and agreed upon by physician referral. When these potential participants entered a safe post-stroke window (i.e., were medically 27 stable), they were approached and provided with background information on the study. After the patient provided informed consent, thorough chart examination was completed to verify that the patient met the inclusion/exclusion criteria. It was taken into consideration that some stroke participants may have had significant cognitive impairment at recruitment. For this reason, a conservative method to ensure proper consent/assent of persons who possibly lacked the capacity to provide full consent was followed. In addition to the patient's consent, the consent of a close family member was obtained for participants who scored less than 20 on the MMSE (a level that raises the possibility that the patient may be unable to provide consent). A copy of the signed consent was given to participants and family member/proxy for their information and their records. Procedure Participants underwent neuropsychological testing at baseline and at follow-up (at completion of the cognitive intervention program). The neuropsychological examinations were used to determine the levels of cognitive ability in the areas of attention, language, visuospatial skills, executive function and memory. A self-reported measure of depression was also completed by each participant. Measures to determine pre-training and post-training functional status were completed by the patient's caregiver. All participants (n = 18) continued to receive standard stroke treatment already in place. This was a randomized control trial involving a 1:1 random allocation of each participant into either the experimental or control condition. The experimental group (n = 9) additionally received specialized VS/VM training and the other half (n = 9) served as controls receiving only standard treatment. The flow of participants for the study is shown in Figure 1. The randomized control design of the project addressed best practice principle #1. Training for the 28 experimental group occurred in hospital for 1 hour, 5 days/week for 4 weeks. The intensity of this project addressed best practice principle #2. The groups were matched as closely as possible (e.g., age, gender, education, clinical factors) by making frequent demographic comparisons as participants joined the study. Patient recruitment was conducted for 7 months. Implementing training during the patient's hospitalization rendered close to 100% compliance with only 3 missed sessions overall across all participants (due to conflicting medical appointments), which were subsequently made-up. Only one patient who was approached to participate in the study declined the invitation, and participants that were enrolled all reached their target completion date. Components of Cognitive Training Intervention A comprehensive stroke intervention program was developed by integrating 4 types of previously evaluated perceptual remediation techniques: visual scanning, video-gaming, visual imagery training, and complex VS/VM construction. The complete intervention program collectively addressed best practice principles #3-7. Visuospatial scanning. Five-to-ten minutes of each training session was devoted to the Mesulam Cancellation Test (Mesulam, 1985). Cancellation tests are one of the most popular tools for evaluating visuospatial attention, visual scanning patterns, and neglect problems (Byrd et al., 2004; Halligan et al., 1992; Lowery et al., 2004; Weintraub & Mesulam, 1988). For this task, the patient was required to circle a certain "target symbol" amongst a host of distracters. This task required active scanning and trunk movement to the left and right sides of the visual field. The targets were varied with respect to stimulus shape, set sizes, and array layouts, thus making this task appropriate for training purposes 29 (Friedman, 1992; Halligan et al., 1992; Wilson et al., 1987). This component of training addressed best practice principles # 3-4. Complex vtsuospatial construction. Fifteen-to-twenty minutes of each training session was devoted to Block Design [Wechsler Adult Intelligence Scale (WAIS)-IV] which is a task that required patients to assemble blocks to match a model drawing. This activity was used to train complex, high-level visuospatial skills (Wechsler, 2008). This component of training addressed best practice principle # 5. Complex VS/VM activity. Fifteen-to-twenty minutes of each training session was devoted to playing the commercially available game "Pac-Man". This video-game encapsulates visually guided ability and requires a substantial degree of VM control to navigate its virtual environment. Furthermore, the VM demand automatically increases as one's performance improves. This component of training addressed best practice principle # 6. Mirror neuron training. Fifteen minutes of each training session required patients to observe others engaging in motor activities (e.g., watching a tennis match). Patients were encouraged to verbalize each action that they were imagining (e.g., serving) in order to verify their engagement in the absence of overt movement. This component of training addressed best practice principle # 7. Weekend maintenance homework booklet. Throughout the duration of training, maintenance stimulation was achieved by workbook activities comprised of visuospatial, visuoconstructive and visuomotor tasks (e.g., mazes, "correct rotation", "find the differences". See Appendix A). Participants were encouraged to engage in these tasks for 2 hours over the weekend. Each participant kept a log of their hours and at the beginning of 30 each week and completion of homework was monitored and checked for correctness. If a component was incorrectly completed, it was returned on the following weekend and the patient was asked to try again. Standard treatment. In addition to VS/VM cognitive training, standard rehabilitation was provided for all participants. Standard stroke therapy encompassed physiotherapy, occupational therapy and speech therapy. These treatments aim to address common consequences of stroke such as paralysis, functional disability, social handicap and aphasia (World Health Organziation, 1993). Physiotherapy is concentrated on improving controlled movement and muscle strength and alleviating spasticity and contractures (Langhorne et al., 1996). Occupational therapy assesses how sensory and motor deficits impact independent functioning and then aims to decrease disability due to these impairments (Donkervoort, Dekker, Stehmann-Saris, & Deellman, 2001). Speech therapy makes use of auditory stimuli (e.g., music), and visual stimuli (e.g., drawings) to improve language impairment (Roth F.P. & Worthington C.K., 2010). Neuropsychological Primary Outcome Measures The neuropsychological test battery was selected to index all major cognitive domains (executive, language, visuospatial and memory) and was composed of tests that have been recently suggested to be sensitive measures for stroke by the National Institute of Neurological Disorders and Stroke and the Canadian Stroke Network (Nyenhuis et al., 2009). The battery required a reasonably short time period to administer (approximately 60 minutes), and had a sufficient range of difficulty (floor & ceiling effects) for patients. All patients were administered this battery pre-intervention and post-intervention. 31 Executive domain: Animal Naming Test. Animal Naming is a common executive category fluency test (Barr & Brandt, 1996), chosen because of its large standardization samples (Crossley, D'Arcy, & Rawson, 1997; Kozora & Cullum, 1995; Seines et al., 1991), its high reliability (test re-test ICC = .90) (Abwender, Swan, Bowerman, & Connolly, 2001) and its prior use in stroke studies (Canning, Leach, Stuss, Ngo, & Black, 2004). Studies have reported that it is useful in differentiating Alzheimer's disease from vascular dementia patients (Canning et al., 2004). The patient is required to list as many animals as possible in one minute and the score is the number of correct responses. Attention domain. Trail Making Test. Trail making measures a variety of abilities including visuomotor, working memory and executive set shifting (Reitan & Wolfson, 1993). It has several standardization samples (Heaton, Miller, Taylor, & Grant, 2004; Ivnik, Malec, Smith, Tangalos, & Petersen, 1996; Seines et al., 1991) and has demonstrated sensitivity to VCI (O'Sullivan, Morris, & Markus, 2005; Padovani et al., 1995). It possesses high consistency (Cronbach alpha = .96) (Kopp et al., 2008) high reliability (test re-test r = .96) (Reynolds, 2006). Trails A presents numbers from 1 - 25, and the patient is required to connect the numbers in ascending order. Trails B, presents circles that include both numbers (1-13) and letters (A - L) and patient is required to connect the circles in an ascending order, alternating between the numbers and letters (i.e., 1-A-2-B-3-C). Both trails A and B are scored for time to completion. Processing speed domain. Digit Symbol (DS). Digit Symbol is part of the WAIS- III and measures executive and processing speed. This test has a large national standardization sample (Wechsler, 1997) and it possesses high reliability (test re-test ICC = .87; inter-rater ICC = .74) (Hinton-Bayre & Geffen, 2005). This test has been used in several studies 32 involving individuals with VCI(Mendez, Cherrier, & Perryman, 1997; Padovani et al., 1995; Tei et al., 1997; Wechsler, 1997) and is sensitive to vascular pathology (O'Sullivan et al., 2005). The patient is required to match symbol-number pairs and the score is the number of correct pairs produced in two minutes. Language domain. Boston Naming Test (BN). BN is the most frequently used confrontation language naming test (Goodglass, Kaplan, & Barresi, 2001). Many normative studies are available (Ivnik et al., 1996; Tombaugh & Hubley, 1997; Welch, Doineau, Johnson, & King, 1996) and it has been used in many studies containing subjects with potential VCI (Waite, Broe, Grayson, & Creasey, 2001). It possesses high internal consistency (Cronbach alpha = .90) (Graves, Bezeau, Fogarty, & Blair, 2004) and high reliability (test re-test r = .91) (Flanagan & Jackson, 1997). Patients are required to name the item in the picture and the score is the number of items correctly named. Visuospatial domain. Rey-Osterrieth Complex Figure Copy (REY-C). This frequently used visuoconstruction task is brief, inexpensive and relatively culture and language free (Rey, 1941). Several standardization samples are available (Chiulli, Haaland, Larue, & Garry, 1995; Stern et al., 1994). The test has been used with vascular patient groups (Diamond, DeLuca, & Kelley, 1997). It possesses high consistency (Cronbach alpha = .94) (Tupler, Welsh, Asare-Aboagye, & Dawson, 1995) and high reliability (test re-test r = .94) (Deckersbach et al., 2000). Patients are required to copy a complicated picture and a score is given based on location and accuracy of picture parts (Stern et al., 1994). Memory domain. Hopkins verbal learning test (HVLT). HVLT is a popular verbal memory task that includes three learning trials and a 20 minute delayed recall condition (Brandt & Benedict, 2001). The HVLT has been used in studies of vascular patients (De 33 Jager, Hogervorst, Combrinck, & Budge, 2003). It possesses reliability (r = .50) that is comparable to test-retest correlations reported for other tests of verbal memory (e.g., Logical Memory subtest of the Wechsler Memory Scale-Revised, California Verbal Learning Test) (Rasmusson, Bylsma, & Brandt, 1995). The sum of items recalled across the three learning trials provides the total acquisition score and represents short term verbal memory. The number of items recalled upon delay represents long term memory integrity. Rey-Osterrieth Complex Figure Delayed Recall (REY-D). This visual memory drawing condition of the Complex Figure (Rey, 1941) occurs 20 to 25 minutes after the initial copy condition. Patients are required to draw free-hand what they remember from the initial diagram presentation. Chiulli et al. (1995) scoring criteria were used. This test possesses high internal consistency (Cronbach alpha = .90) (Rapport, Charter, Dutra, Farchione, & Kingsley, 1997) and high reliability (test re-test r = .90) (Deckersbach et al., 2000). Attention domain. Digit span. Digit span is the most common test used for measuring attention and short term working memory (Lezak, 1995). It consists of seven pairs of random number sequences that the examiner reads aloud. The patient is required to repeat the numbers in the same order presented (digit forward) or to repeat the numbers in reverse order (digit backward). Both tests possess strong reliability (test-retest r = .89) and widespread validity (Kaufman, McLean, & Reynolds, 1991). The WAIS standard scoring system was used. Screening/Global domain. Mini-mental State Examination (MMSE). The 30-point MMSE is a popular general cognitive screening examination (Folstein, Folstein, & McHugh, 1975). It is known for quantitatively assessing the severity of cognitive impairment 34 (Tombaugh & Mclntyre, 1992). Internal consistency is strong (inter-rater IIC = .90) (Molloy & Standish, 1997). This quick-to-administer test examines a broad range of ability including: orientation, word recall, working memory, naming, repetition, comprehension and drawing. A score of greater than 17 was required to meet criteria for study entry Boston Diagnostic Aphasia Examination (BDAE). This auditory comprehension test was used to screen for significant receptive aphasia (Benton & Hamsher, 1987). In the test, patients are instructed to follow certain instructions and the total score is the number of correctly executed responses. A score of greater than 10 was required to meet criteria for study entry. Montreal cognitive assessment (MOCA). This quick-to-administer test is composed of a five word immediate recall, delayed recall and recognition task, a six item orientation (e.g., to time and place) and a one letter phonemic (letter f) fluency task. This test was chosen because of its widespread assessment of cognitive ability and because it demonstrates high test-retest reliability (r = 0.92) and internal consistency (Cronbach alpha = 0.83) (Nasreddine et al., 2005). Neuropsychiatric/Depressive domain. Geriatric depression scale (GDS). The GDS is a widely used self-report depression inventory. The score is the number of reported items that signify pathology. It was used as a detailed index for mood and represents a valid and reliable measure of depression (Yesavage et al., 1982). Functional/Activities of daily living (ADL). Informant questionnaire for cognitive decline in the elderly, short form (IQCODE). 35 The short form is a 16-item scale that is completed by a proxy and compares current cognitive function to pre-stroke cognitive abilities. Each item is a five-point Likert scale and the total score is the sum of the points across the 16 items. This form demonstrates high reliability (test-retest = .97) and validity (Jorm, 1994; Jorm, 2004). Disability assessment for dementia (DAD). The DAD (Gelinas, Gauthier, Mclntyre, & Gauthier, 1999) measures both basic and instrumental activities of daily living (IADL) in patients with cognitive impairment and dementia. It possesses high internal consistency (Cronbach's alpha = .96) and reliability (test re-test ICC = .96; inter-rater ICC = .95) and has been used in several clinical trials assessing dementia agents (Erkinjuntti et al., 2003; Feldman et al., 2001; Orgogozo, Small, Hammond, Van, & Schwalen, 2004; Suh et al., 2006). Barthel. The Barthel is a popular stroke instrument (Foulkes, Wolf, Price, Mohr, & Hier, 1988) that measures basic ADLs. It is both a valid (Graham, Emery, & Hodges, 2004; Loewen & Anderson, 1990) and reliable (Collin, Wade, Davies, & Home, 1988) measure of disability in the stroke population. Results The results of this study were evaluated using multivariate analysis of variance (MANOVA) for all measures at pre-intervention and post-intervention. Non-significant group differences at pre-intervention combined with significant group differences at postintervention would be indicative of intervention success. One-way analysis of variance (ANOVA) was used on demographic variables to confirm that the participant groups were equal at baseline. It was also important to evaluate the changes occurring within each patient 36 group, so a repeated measures analysis from pre-intervention to post-intervention was conducted for each group. Effect sizes were used to interpret all significant p-values. Pre-intervention Assessment Between Groups In order to confirm that the groups were comparable prior to the experimental intervention, a one-way ANOVA was conducted between patient groups (experimental versus control) on all demographic tests. There were no significant between-group differences on any of the demographic measures: age (F(l) = 0.40, p = .538), education (F(l) = 0.63, p = .440) or days since stroke (F(l) = 1.23, p = .285). MANOVA results for neuropsychological pre-treatment means, standard error, F- value and between the groups are presented in Table 4. There were no significant between-group differences observed on any of the neuropsychological measures. Therefore, the two groups were equal at baseline. Post-Intervention Differences Between Groups To evaluate cognitive differences between groups at post-intervention, MANOVA was conducted between patient groups on all neuropsychological measures. Neuropsychological post-treatment means, standard error, F-value, df and effect sizes between the groups are presented in Table 5. A main between-group effect was observed on all the measures except Line Orientation, Digit Forward, Digit Backward, Digit Symbol, Trails A and Trails B. However, Digit Backward, Digit Symbol and Trails B are significantly different when using ANOVA (Digit Backward, F(l, 16) = 4.30, p < .05; Digit Symbol, F(l,16) = 4.24, p < .05; Trails B F(l,16) = 4.17, p < .05). All significant between-group differences at post-intervention were accompanied by large effect sizes, ranging from 0.97 to 2.22. Figure 2 compares the means for the MMSE, Boston Naming, Rey Copy, HVLT Delay, Digit Backward, Digit Symbol and DAD to illustrate the extent of post-intervention 37 differences between the groups in functioning and in each neuropsychological domain (global, language, visuospatial, verbal memory, processing speed and activities of daily living, respectively). Within Group Improvements An analysis examining the treatment effects within each group was conducted to evaluate cognitive changes within the groups from pre-intervention to post-intervention. Repeated measures analysis was performed for both groups. This type of analysis benefits from the fact that each subject serves as their own control, providing a way to reduce variability so that the analysis can focus more precisely on treatment effects. Pre-treatment and post-treatments means, standard error, F-value, df and effect sizes for both groups are presented in Tables 6 and 7. Within group analysis showed that the intervention group significantly improved on every outcome measure from pre-intervention to post-intervention. Furthermore, all improvements were accompanied with large effect sizes, ranging from .40 to 2.35. The control group showed select improvement from pre-intervention to postintervention on: Animals, HVLT, Digit Symbol, Apathy and Barthel test scores. Improvements were accompanied with small effect sizes, ranging from 0.23 to 0.35. There were no significant improvements on the remaining tests. Figure 3 compares group changes from pre-intervention to post-intervention on the MMSE, Boston Naming, Rey Copy and Digit Symbol. These tests are the most telling in their illustration of how the experimental group showed improvement whereas the control remained the same. Magnitude of Improvement Between Groups Having found that there were significant improvements in both groups for Animals, HVLT, Digit Symbol, Apathy and Barthel test scores, the next step was to discover whether 38 the intervention group improved significantly more than the control. Change scores (i.e., improvement) were calculated by subtracting baseline scores from post-treatment. Next, the improvements between the two groups were compared using independent r-tests. The experimental group improved significantly more than the control group on each test: Animals (f(8) = 5.00, p = .001), HVLT (r(8) = 8.74, p < .001), Digit symbol (t(8) = 5.86, p < .001), Apathy (f(8) = 5.13, p = .001) and Barthel (f(8) = .95, p < .001). Table 8 compares the mean improvement for each test between the groups and their significance level. Figure 4 shows the mean change for each test to illustrate the difference in the magnitude of improvement between the groups. Training Outcome Measures To evaluate the performance of the experimental group on the specific training measures, an analysis was completed for Pac-Man, Block Design and the Mesulam Cancellation task. Enhanced performance on trained tasks from initial weeks (weeks 1-2) to final weeks (weeks 3-4) provides unique information about learning by the intervention group. Pac-man task. For participants engaging in training, high scores as well as duration of play (i.e., keeping Pac-man alive) was documented in each training session. Longer duration time suggests that the participant was improving at the task (e.g., due to improvement in following rules and avoidance maneuvering). The analysis utilized paired Mests to compare the group's overall high scores and duration played between weeks 1-2 and weeks 3-4. Significantly higher scores were observed on weeks 3-4 versus weeks 1-2 (t(8) = 2.73,/? = .026). Figure 5 displays high-scores for initial weeks (1-2) to final weeks (3-4) of training. Likewise, paired /-test for overall duration of time played showed significantly longer time from weeks 1-2 to weeks 3-4 (/(8) = 5.62, p = .001). Figure 6 shows that participants increased their duration of play from weeks 1-2 to weeks 3-4. Block Design task. For participants engaging in training, a record was taken of how long it took to assemble blocks to match a series of model images. The analysis utilized paired Mests to compare the group's overall duration on this task between weeks 1-2 and weeks 3-4. Shorter duration time signified that the participant was improving at the task. Significant differences were observed by faster assembly time from weeks 1-2 to weeks 3-4 (f(8) = 8.01, p = < .001; See Figure 7). Mesulam Cancellation task. For participants engaging in training, a record was taken of how many target items were found on the left (60 targets) and right (60 targets) visual field over a period of 7 minutes. Paired /-test analysis was used to compare the participant's mean scores from initial weeks versus final weeks for both left (M = 35.93, SD = 18.64 versus M = 52.36, SD = 10.98) and right (M = 41.68, SD = 12.88 versus M = 52.81, SD = 9.54) visual fields. Significant differences between weeks 1-2 and weeks 3-4 was found for the group for both the left (r(8) = 5.51, p < .01) and the right (t(8) = 3.34, p < .05) visual search fields. Of particular interest were the performance improvements of two neglect patients (participants #1 and #2) to determine if there were significant improvement in their ability to locate targets in their neglected visual field (i.e., left visual field). For participant #1 and #2, individual paired ttests were used to compare their overall number of targets on the left side between weeks 1-2 and weeks 3-4. Left side targets at weeks 1-2 versus weeks 3-4 for participant #1 (M = 11.70, 40 SD = 10.13 versus M = 40.80, SD = 6.44) was significant on Mest analysis (t(9) = 8.66, p < .001). Likewise, left side targets at weeks 1-2 versus weeks 3-4 for participant #2 (M = 7.50, SD = 9.59 versus M = 25.20, SD = 10.96) was significant on Mest analysis (t(9) = 7.42, p < .001). Homework booklet. Each participant followed the instructions to complete paper and pencil VS/VM activities for 2 hours over the weekend. Compliance to this component of the program was 100%. With the help of the caregivers, the participants were able to keep a log of their hours, thus making it possible to confirm completion and check for accuracy at the start of each week. On the rare occasion that a task was incorrectly completed (occurring only a few times collectively), the incorrect pages were added to the booklets on the following weekend and the patient was asked to try again. There was no instance in which pages were returned for a third time. Discussion The goal of this research was to determine if VS/VM training is an effective intervention tool for improving acute post-stroke cognitive recovery. The intervention for the experimental group was delivered as intended. Intervention occurred for 1 hour/day, 5 days/week for 4 weeks and involved a number of VS/VM training techniques such as visual scanning, video-gaming, visual imagery, complex block construction and weekend maintenance homework assignments. As hypothesized, the results of this randomized control trial showed that the incorporation of cognitive training into conventional rehabilitative treatment was more effective in improving cognition, function and mood than conventional treatment alone. Control patients, receiving only standard rehabilitative treatment, were 41 consistently outperformed by the intervention group who engaged in the VS/VM training procedure. Results showed that the experimental group performed better on all the following cognitive domains: global, visuoconstructive, language, visual memory, verbal memory, executive function, processing speed, depression, and activities of daily living. Although it was readily apparent that the participant groups were different at post-intervention, it is also important to evaluate and understand the process of change occurring within each group. Participant Improvements Within Groups Cognitive improvements occurred in both groups throughout the 4-week study period. The intervention group made significant improvements in all domains and the controls made selective improvements in short term memory and processing speed. Such changes are to be expected, given that approximately 16% of stroke patients with cognitive impairment spontaneously improve (Teasell et al., 2006). Spontaneous recovery is learning due to functional and structural reorganization in the brain that naturally occurs weeks to months following stroke (Saposnik et al., 2010; Teasell et al., 2006). Based on the values associated with spontaneous recovery (i.e., 16%) and the number of participants in this study (i.e., 18), one could expect this phenomenon to possibly affect only 2 or 3 of these individuals. Conversely, the results here demonstrate significant improvements, both within experimental group and between experimental and control group, that far exceeded 2 to 3 individuals, making spontaneous recovery an unlikely explanation. Even if spontaneous recovery is thought to be a significant factor involved in recovery, then it must be equally applied to both groups with comparable pre-treatment baseline. However, the fact that the magnitude of improvements made by the intervention group were significantly greater than the improvements made by the control group provides solid evidence to argue that there was 42 a specific intervention effect that could not be attributed to spontaneous recovery. Also, the significant difference in the magnitude of improvements seen between the intervention and control groups informs us that without cognitive training, patients are not reaching their full potential, even if progress is observed. For example, although control patients showed improvement on short term memory and processing speed, these improvements paled in comparison to the improvements seen in the intervention group. However, because these improvements were common in both groups, it seems reasonable to speculate that these domains are the most responsive to rehabilitation efforts. This speculation originates from clinical research showing that memory is relatively preserved in stroke patients (Kalaria & Ballard, 2001), thus possibly making standard care somewhat successful for patient improvements. However, the present study showed that these improvements were nowhere near the level of improvement observed in patients that engaged in the VS/VM cognitive training procedure. Intervention Improvements on Trained Tasks Increased training ability was observed on all tasks throughout the course of the intervention. Experimental participants demonstrated improvements in Pac-Man high score, duration of Pac-Man play and block design construction. Enhanced performance on training can be taken as proof of learning, which suggests that the generation of new neuronal connections was likely occurring (Belichenko, Mattsson, & Johansson, 2001; Greenwood & Parasuraman, 2010; Hadjiev & Mineva, 2008; Mazmanian, Kreutzer, Devany, & Martin, 1993). Furthermore, the program showed promise in alleviating symptoms of neglect, as two patients with severe left-sided neglect showed significant improvement on the Mesulam cancellation tasks at program conclusion. Additional anecdotal evidence for alleviating 43 symptoms of neglect was evident in the participants' ability to correctly complete the activities in their homework book as this involves tasks that heavily relied on intact scanning abilities. It is challenging to untangle the unique contribution that motor imagery added to the overall outcome of the study. Research examining the neurophysiological bases of motor imagery is what provided the theoretical justification to incorporate this form of training into the program. Evidence from a number of sources has been used to suggest that motor imagery involves the same neural mechanisms as are involved in the preparation and planning of actual movements (Decety & Ingvar, 1990; Decety, 1996; Feltz & Landers, 1983; McCarthy et al., 2002; Richards et al., 1993; Tatemichi et al., 1994; Tyszka, Grafton, Chew, Woods, & Colletti, 1994). On this basis, it can be deduced that mental practice of motor skills may have helped participants improve at transitioning between sensory preparation and motor action. This refinement in sensory-motor transition may have provided a beneficial effect on the actual performance of motor activity such as playing Pac-Man. A final argument for the use of motor imagery for stroke rehabilitation is the evident free time that patients spend in non-rehabilitative activities and the need to design rehabilitation tasks that they can perform safely alone (Bernhardt, Chan, Nicola, & Collier, 2007). Motor imagery could provide a means for allowing patients to spend more time in rehabilitationrelated activity. Unsuccessful Intervention Outcomes Using a MANOVA to evaluate post-intervention group differences, there were non­ significant differences for Line Orientation, Digit Forward, Digit Backward, Digit Symbol, Trails A and Trails B. However, an evaluation of these tests using ANOVA showed that 44 Digit Backward, Digit Symbol and Trails B were significantly different. Therefore, at postintervention only two domains, visuospatial (Line Orientation) and attention (Digit Forward and Trails A), were consistently not significantly different between the groups. One explanation for these non-significant group differences can be suggested by taking an indepth look at the properties of the tests used. That is, the visuospatial and attention tests that were used were either extremely sensitive to right hemisphere damage (i.e., Line Orientation) or not sensitive enough (i.e., Digit Forward and Trails A), making it difficult to detect between group differences. A test that is non-sensitive to right hemisphere functioning may require more than 4 weeks of training to show improvement whereas tests that are very sensitive may not be able to detect true changes between participant group. In any case, on the basis of the observed effect sizes for Line Orientation, Digit Forward, Digit Backward, Digit Symbol, Trails A and Trails B, significant MANOVA post-intervention differences would nonetheless be found with a sample size of 60, 32, 22, 20, 60,24 (respectively). Therefore, these few non-significant results, which would be better powered with the accrual of subjects into the program, are marginal in light of the vast improvements produced in a short period of 4 weeks. Possible Mechanisms for Post-Intervention Success It is important to explore the theoretical underpinnings that may explain why VS/VM training was so effective. Cognitive training is an example of a behaviour that promotes neuronal activity and results in improved cognitive function (Greenwood & Parasuraman, 2010). There are 3 mechanism that can be highlighted that may have played a role in the success of the intervention: (1) brain derived neurotrophic factors (BDNF), (2) cortical reorganization and (3) synaptogenesis. 45 Brain derived neurotrophic factors. The success of cognitive intervention may be attributable to neurotrophic enhancement of BDNF. BDNF is a protein produced in the subgranular zone of the hippocampus that promotes neuron growth and prevents neuronal apoptosis (Durany et al., 2000; Zhang et al., 2002). The hippocampus is essential for learning and memory and thus enhancement of the hippocampus is key for overall improved cognitive performance. On the basis of other studies, intervention activities most likely facilitated increased BDNF production, fostering greater post-stroke cognitive recovery by enhancing neuron survival and axon regeneration. Researchers have reported that when learning occurs, as was demonstrated by the intervention participants, the expression of BDNF is subsequently enhanced. For example, studies on rats have demonstrated that compared to controls, rats that are trained on VS radial mazes show significantly elevated BDNF protein levels in the hippocampus (Hall, Thomas, & Everitt, 2000; Kesslak, So, Choi, Cotman, & Gomez-Pinilla, 1998). Furthermore, increases in the expression of BDNF are reported to occur immediately after VS maze learning, and are thought to be responsible for superior VS retention seen in the trained rats compared to their control counterparts (Ma, Wang, Wu, Wei, & Lee, 1998). Upregulation of BDNF after VS training has been replicated in monkeys (Tokuyama, Okuno, Hashimoto, Xin, & Miyashita, 2000). Furthermore, the findings from monkeys have been expanded to show that VM training (i.e., learning how to use tools) also results in BDNF surges in several areas of the cortex, such as the temporal and parietal lobe (Ishibashi et al., 2002). VS learning is believed to directly increase the signalling between BDNF and it's receptor Tyrosine Kinase B (TrkB), resulting in receptor autophosphorylation and subsequent activation of downstream signal transduction pathways (Yamada, Mizuno, & Nabeshima, 2002). In fact, the connection between VS learning and TrkB phosphorylation is 46 so tight that they are reported to move in parallel without any changes in the phosphorylation of closely related receptors, TrkA or TrkC (Mizuno et al., 2003). Furthermore, the use of antisense oligonucleotide to block the expression of BDNF results in impaired spatial performance and the complete elimination of TrkB phosphorylation (Mizuno et al., 2003). Collectively, these finding supports the link between VS learning and the activity of BDNF pathways. The presence of BDNF can then enhance cognitive abilities through its intricate role in synaptic strength, learning and memory (Yamada, Mizuno, & Nabeshima, 2002). Further research into the neurotrophic mechanism of cognitive training is warranted (and necessary) to support the involvement of BDNF. Antidepressant effects were another observed benefit of specialized training in the experimental group. Evidence of why this may have occurred could also be linked to an increase in BDNF. Research has shown that there is an inverse link between BDNF and depression (Durany et al., 2000; Schmidt & Duman, 2010). One of the findings in this project that fits most tightly with the notion of BDNF was the rate of depression observed at postintervention. It was shown that the intervention group was significantly less depressed than the controls at post-intervention. Thus, the antidepressant effect post intervention may have been a reflection of BDNF increases that may have occurred as described above. Furthermore, the presence of BDNF has been linked to adult neuroplasticity (Large et al., 1986; Yan et al., 1997) which is a convincing explanation for why the benefits of a specific VS/VM training program generalized to several cognitive domains that were not a focus of intervention (e.g., executive and functional activities). Such a generalizing influence, particularly to executive and functional abilities, has significant implications regarding the prevention of vascular dementia because impairments in these two domains are considered its 47 hallmarks (Levin, 2011). Our ability to rapidly intervene on the leading symptoms of vascular dementia could mean the difference between the development of this disease or its prevention. Aside from hippocampal and parietal expression of BDNF, it is known that astrocytes are also a source of BDNF (Dougherty, Dreyfus, & Black, 2000). Astrocytes play an important protective role in regulating the blood brain barrier (Abbott, Ronnback, & Hansson, 2006) and an important healing role in CNS injury by phagocytising cellular debris, and thus after a stroke episode, they are intensely recruited to the site of injury (White & Jakeman, 2008). Therefore strategies that potentially increase levels of astrocyte BDNF (such as the current project) may thereby dramatically elevate BDNF to the injured region, simultaneously harnessing the beneficial roles of both astrocytes and BDNF that are needed to foster neuronal survival and regrowth. Cortical reorganization. Apart from neurotrophic explanations, the success of cognitive intervention may also be attributable to enhancement of cortical neuroplasticity. Neuroplasticity refers to changes at the neuronal level that can be stimulated by experience (Chen, Rex, Sanaiha, Lynch, & Gall, 2010) and it is thought to enable the lesioned brain to reorganize itself after damage (Wingfield & Grossman, 2006). Evidence that cortical reorganization occurs following stroke is demonstrated when remote neurons assist or take over function (Ro et al., 2006; Taub, Uswatte, & Elbert, 2002). For example, studies utilizing fMRI to address post-stroke neuroplasticity and cognitive performance show that intact cognitive performance is associated with compensatory activation in ipsilateral (Cao, Vikingstad, George, Johnson, & Welch, 1999; Feydy et al., 2002) and homologous contralateral regions (Carey et al., 2002; Lee et al., 2009). Therefore, there is a need for 48 compensatory processes in stroke brains, such that more cortical resources are needed to carry out a task that fewer regions can do in normal brains. VS/VM cognitive training may have allowed the intervention group to access the additional resources necessary for intact performance (i.e., training induced functional reorganization) whereas the control group may not have received this opportunity. The specific plastic response that would be expected to occur in response to the current VS/VM (i.e., parietal) training program would be increased compensatory activation in premotor regions. Compensatory prefrontal activation would be expected because of the dense projections from parietal to prefrontal regions. For example, parietal areas 5 and 7 are known to project to supplementary premotor areas (Kandel et al., 2000). The reason for such interconnectedness between the parietal and frontal region is because the parietal association area is critical for integrating different sensory modalities which must be directed and used by prefrontal regions to plan motor behaviour. Research has also shown that learning is associated with increases in premotor activity even within a single session of practice (Weissman, Woldorff, Hazlett, & Mangun, 2002), thus making a 4 week training program ample time to induce the functional reorganization that I have proposed here. Synaptogenesis. A final factor that may have played a role in the success of this cognitive intervention may be the formation of new neuronal connections via synaptogenesis. Recent evidence shows that the formations and remodeling of dendritic spines are induced by cognitive training (Greenwood & Parasuraman, 2010). The presence of new dendrites is a meaningful finding because they are thought to be one of the key players in neurogenesis, with the potential to allow for structural plasticity (Crick, 1982; Geinisman, Morrell, & deToledo-Morrell, 1989), and compensation of functional losses that are associated with 49 stroke. For example, studies using rat models of cerebral ischemia have shown that poststroke exposure to enriched environments can increase synaptogenesis (Belichenko et al., 2001) and can significantly improve functional outcomes (Grabowski, Sorensen, Mattsson, Zimmer, & Johansson, 1995). Synaptogenesis following exposure to enriched environments has also been reported to occur even weeks after stroke (Johansson, 1996). Furthermore, such increases in dendritic spines have been confirmed as "active" members in the cortical network, expressing postsynaptic potentials and spontaneous action potentials (Kokoeva, Yin, & Flier, 2005; Song, Stevens, & Gage, 2002) and receiving inputs from the established neuronal network (Toni et al., 2008). Synaptic plasticity would be expected in our intervention participants because when learning occurs, the process of synaptogenesis is initiated (Greenwood & Parasuraman, 2010) and then the connection between newly formed synapses are consolidated by long term potentiation (LTP). LTP is a long-lasting increase in synaptic efficacy that is induced by learning and facilitates the wiring of neurons (Whitlock, Heynen, Shuler, & Bear, 2006). Accordingly, the following is a proposed model for the role of cognitive training in synaptogenesis and LTP: newly formed synapses between cells that are believed to be induced by intervention learning would not yet be expected to have meaningful connections and would mainly contain a few NMDA (N-methyl D-aspartate) and AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) glutamatergic receptors (Richards, Clark, & Clarke, 2007). However, daily practice of the training activities may have helped newly liberated synapses to coincide (i.e., fire together) and in turn strengthen (i.e., wire together). When the new pre-synaptic neuron releases glutamate that coincides with the firing of a post-synaptic neuron, its NMDA receptors are activated via calcium (Ca2+) entering the cell (Muller, Nikonenko, Jourdain, & Alberi, 2002). The resulting 50 increase in Ca2+ influx triggers a cascade of events that eventually leads to an increase in the number of AMPA receptors inserted into the membrane (Richards et al., 2007). As a result, the next time this pre-synaptic neuron releases glutamate, the excitatory post-synaptic potentials will be bigger; and thus LTP is established, cortical synaptic activity is amplified and cognitive abilities improve. Clinical Relevance The findings from this study have important clinical relevance for informing and shaping stroke rehabilitation towards the implementation of cognitive exercise into routine practice. Importantly, cognitive intervention programs can be implemented safely among individuals in the acute stroke phase without negative effects on participation in conventional stroke rehabilitation, as evidenced by the success of this program. Furthermore, the fact that there were no problems with participants completing all components of the program (including the homework booklet), and that there were no dropouts, provides a good benchmark for the feasibility of such a program. Effect sizes are an important tool that can supplement standard statistical testing and can facilitate the interpretation of research findings in clinical setting. An effect size represents the magnitude of change between two groups. It tells us how meaningful differences are between groups (Zakzanis, 2001). An effect size of .5 has been outlined in the literature as the minimal threshold level at which research findings begin to reach clinical significance (Donkervoort et al., 2001). The effect sizes that accompanied our findings far exceed this criterion, indicating that there were strong meaningful differences between the groups. Furthermore, the fact that the cognitive intervention therapy was only a subsection of the total rehabilitation process, yet still produced such large effect sizes, makes an even 51 stronger case for its efficacy. The clinically important findings observed in this study are relevant to both physicians and patients. Physicians can interpret the study's clinically important outcomes as a therapeutic effect or a meaningful change in the prognosis of stroke. As for the patients, a clinically important change would represent a meaningful reduction in their symptoms or improvement in post-stroke function that would lead to improved quality of life. Limitations Aside from test sensitivity determinants that may have contributed to the non­ significant post-intervention findings in visuospatial and attention abilities, it is important to note that the effects of location and severity of brain damage are also relevant to understanding the dynamic process occurring in acute stroke recovery. Visuospatial and attention abilities have been documented as the most persistent cognitive impairments arising from vascular etiology (Graham et al., 2004) and imaging analysis may be able to indicate if these intervention outcomes are related to severity and location of stroke. Imaging analysis was beyond the scope of the current project, but future research looking at the neurological factors in relation to intervention outcomes would enhance our understanding of cognitive rehabilitation and allow us to develop more effective cognitive intervention programs. It is also important to note that the use of change scores does not control for the possibility that change scores may be correlated with baseline values, thus complicating the interpretation of results. Some researchers have suggested alternative approaches of analysis (e.g., Analysis of Covariance) (Vickers & Altman, 2001) but the general caveat is having a large enough sample size. Although the sample size of the current project did not afford such alternative analysis, similar studies involving randomized control trials with a restricted 52 sample provides precedence that the use of change scores is appropriate in this scenario (Altman & Bland, 1999; Donkervoort et al., 2001). Methodological limitations of this study can be identified but they should be evaluated under the lens that this was a pilot project. For example, this study examined the beneficial outcome of incorporating VS/VM training into standard stroke therapy against standard therapy alone as the control group. Accordingly, it can be argued that a drawback to this study design is that the control group did not receive an equivalent amount of time for regular activity as the intervention group. An optimal solution would be for the control group to receive some additional but non-active/sham treatment that is equivalent in duration to the experimental intervention. Another methodological limitation that should be addressed in future projects is that the researcher who did the pre- and post-intervention testing was not blind to the participants' group assignment. Conclusion There is no universally accepted cognitive treatment for stroke. The value of rehabilitation aimed at assisting post-stroke cognitive recovery is becoming well recognized, but strategies designed to address cognitive dysfunction is by comparison poorly developed. This project constituted a step towards understanding the potential benefits of a focused VS/VM training program to affect cognitive change and provided evidence that engaging in early cognitive intervention influences faster recovery through improved cognitive, mood and functional abilities. To this end, the primary objectives of this study were met. Cognitive training programs, such as the one piloted here, may assist in broadening the scope of rehabilitation beyond a physical focus and may assist in addressing the present gaps in rehabilitation service, brain training. Ultimately, the ability to treat stroke-related 53 cognitive dysfunction may translate into a reduction in the occurrence of post-stroke cognitive impairment, reduced burden on health care and a greater quality of life for poststroke individuals. Table 1. Patient Inclusion Criteria Criteria Description Demographic Sufficient English language skill for psychological tests. Psychosocial Availability of a caregiver knowledgeable about the participant's past and recent medical history. Stroke Stroke as indicated by primary physician, with neuroimaging evidence of symptomatic cerebral infarction. Medically stable/managed (e.g., hypertension, blood lipid levels). 55 Table 2. Patient Exclusion Criteria Criteria Psychological Description Moderately severe dementia defined by a Mini-Mental State score of < 17. Severe receptive/expressive aphasia, as measured by a score of < 10 on the Boston Diagnostic Aphasia Examination. Medical Previous/current medical/psychiatric conditions (e.g., epilepsy, dementia, brain tumor, traumatic brain injury or substance abuse). Metabolic or endocrine disorders. Medication Recent use of cognitive enhancing agents (e.g., cholinesterase inhibitors). Current or past history of treatment with psychoactive medications. 56 Table 3. Frequency Distribution for Intervention and Control Group on Stroke Characteristics Intervention (n = 9) 5 Control ( n = 9) 4 Right Frontal 1 1 Right Cerebellar 1 0 Right Unspecified 3 3 4 5 Left Frontal 1 1 Left Unspecified 3 4 Hemorrhage 1 2 Infarction 8 7 Previous stroke 0 1 Hemiplegia/hemiparesis 9 9 Characteristic Total Right CVA Total Left CVA Type of stroke Note. CVA = Cerebrovascular Accident 57 Table 4. Pre-treatment Neuropsychological Comparability of the Intervention and Control Groups Neuropsychological Test Global/Screening MMSE MOCA BDAE Language Boston Naming Visuospatial/V isuoconstructive Line Orientation Rey Copy Clock Visuospatial Memory Rey Delay Verbal Memory HVLT HVLT Delay Working Memory Digit Forward Digit Backward Processing Speed Digit Symbol Trails A Executive Functioning Animal Naming Test Trails B Neuropsychiatric/Behavioural GDS Apathy Evaluation Scale Activities of Daily Living IQCODE Barthel DAD *p < .05 Intervention M (SD) Pre-treatment Control M (SD) F df 20.67 (2.35) 17.11(2.57) 12.89(1.27) 19.00 (3.64) 16.11(3.33) 12.33 (0.87) 1.33 1,16 0.51 1,16 1.18 1,16 38.89 (7.08) 41.11 (5.30) 0.57 1,16 6.33 (4.85) 10.67 (5.10) 5.22 (2.49) 7.00 (4.89) 13.11 (7.03) 4.00 (2.40) 0.08 1,16 0.71 1,16 1.13 1,16 1.67 (3.31) 3.22 (4.58) 0.68 1,16 11.22 (2.33) 2.56(1.88) 10.22 (4.38) 2.00 (2.06) 0.37 1,16 0.36 1,16 5.11 (1.27) 4.00(1.12) 5.44(1.13) 3.00(1.80) 0.35 1,16 2.00 1,16 7.33 (5.39) 145.00(101.00) 9.88 (9.40) 136.11 (100.62) 0.50 1,16 0.04 1,16 10.56(1.42) 257.22 (65.72) 10.78 (1.64) 273.67 (64.14) 0.10 1,16 0.29 1,16 26.67 (9.19) 20.89 (9.70) 23.56 (8.73) 25.11 (4.62) 61.00 (5.33) 64.56 (6.10) 39.44 (8.08) 17.11 (4.07) 0.54 1,16 1.39 1,16 1,16 1.73 1,16 0.56 1,16 0.24 1,16 34.44 (18.45) 18.33 (6.34) 58 Table 5. Post-treatment Neuropsychological Comparability of the Intervention and Control Groups Neuropsychological Test Global/Screening MMSE** MOCA* BDAE* Language Boston Naming** Visuospatial/V isuoconstructive Line Orientation Rey Copy** Clock** Visuospatial Memory Rey Delay* Verbal Memory HVLT** HVLT Delay** Working Memory Digit Forward Digit Backward Processing Speed Digit Symbol Trails A Executive Functioning Animal Naming** Trails B Neuropsychiatric/Behavioural GDS* Apathy Evaluation Scale** Activities of Daily Living IQCODE** DAD** * p < .05. **p<.01. Post-treatment Intervention Control M (SD) M (SD) F df Cohen d 26.00 (2.45) 21.78 (2.99) 14.11(0.93) 19.22 (4.87) 15.89 (6.11) 12.67 (1.22) 13.93 1,16 6.74 1,16 7.95 1,16 1.76 1.22 1.33 52.22 (5.42) 42.22(4.18) 19.19 1,16 2.07 13.11 (6.33) 24.33 (7.21) 8.88 (1.96) 10.44 (7.94) 14.22 (5.76) 4.44 (2.92) 0.62 1,16 8.26 1,16 14.35 1,16 0.47 1.55 0.98 9.33 (5.00) 4.44 (4.85) 4.43 1,16 0.99 18.67 (4.09) 5.11(1.76) 11.78(4.82) 2.33 (2.29) 10.69 1,16 8.31 1,16 1.54 1.36 6.67 (1.41) 4.89 (1.45) 5.67 (1.66) 3.22 (1.92) 1.90 4.31 1,16 1,16 0.65 0.98 21.44 (9.57) 109.11(90.81) 12.11(9.66) 133.78(101.60) 4.24 0.30 1,16 1,16 0.97 0.46 14.56(1.94) 201.56 (77.36) 11.67(1.80) 270.89 (66.31) 10.69 1,16 4.17 1,16 1.54 0.96 11.67 (5.43) 11.11 (6.33) 20.67 (7.14) 23.44 (4.67) 7.16 1,16 22.12 1,16 1.26 2.22 51.11 (6.15) 28.89(11.01) 65.22 (8.74) 16.56 (5.15) 15.68 1,16 9.27 1,16 1.87 1.43 59 Table 6. Post-Treatment Cognitive Changes Within the Intervention Group Outcome Measure Pre-treatment Mean (SD) Post-treatment Mean (SD) F df Cohen d MMSE** 20.67 (2.35) 26.00 (2.45) 85.33 1,8 2.22 Clock** 5.22 (2.49) 8.88 (1.96) 17.93 1.8 1.63 MOCA** 17.11 (2.57) 21.78 (2.99) 31.34 1,8 1.68 BDAE* 12.89(1.27) 14.11 (0.93) 6.91 1,8 1.10 Boston** 38.89 (7.08) 52.22 (5.42) 22.54 1.8 2.11 Animals** 10.56(1.42) 14.56(1.94) 25.04 1,8 2.35 Rey Copy** 10.67 (5.10) 24.33 (7.21) 76.41 1,8 2.18 Rey Delay** 1.67 (3.31) 9.33 (5.00) 54.23 1.8 1.80 Line Orientation* 6.33 (4.85) 13.11 (6.33) 6.93 1,8 1.45 HVLT** 11.22(2.33) 18.67 (4.09) 76.41 1,8 2.23 HVLT Delay** 2.56(1.88) 5.11 (1.76) 21.16 1.8 1.40 Digit Forward** 5.11 (1.27) 6.67 (1.41) 14.26 1,8 1.16 Digit Backward** 4.00(1.12) 4.89(1.45) 11.64 1,8 0.68 Digit Symbol** 7.33 (5.39) 21.44 (9.57) 34.39 1.8 1.81 Trails A* 145.00(101.00) 109.11 (90.81) 6.03 1,8 0.40 Trails B* 257.22 (65.72) 201.56 (77.36) 5.51 1,8 0.78 GDS** 26.67 (9.19) 11.67(5.43) 24.70 1.8 1.98 Apathy** 20.89 (9.70) 11.11 (6.33) 26.32 1,8 1.19 IQCODE** 61.00 (5.33) 51.11 (6.15) 24.37 1,8 1.71 Barthel** 34.44 (18.45) 61.67 (24.75) 35.44 1.8 1.25 DAD* 18.33 (6.34) 28.89(11.01) 9.41 1,8 1.17 * p < .05. ** p < .01. 60 Table 7. Post-Treatment Cognitive Changes Within the Control Group Outcome Measure Pre-treatment Mean (SD) Post-treatment Mean (SD) F df Cohen d MMSE 19.00 (3.64) 19.22 (4.87) 0.11 1,8 0.08 Clock 4.00 (2.40) 4.44 (2.92) 1.73 1,8 0.16 MOCA 15.89 (3.33) 16.11 (6.11) 0.04 1,8 0.04 BDAE 12.33 (0.87) 12.67 (1.22) 2.00 1,8 0.32 Boston 41.11 (5.30) 42.22(4.18) 2.17 1,8 0.23 Animals** 10.78(1.64) 11.67(1.80) 19.69 1,8 0.51 Rey Copy 13.11 (7.03) 14.22 (5.76) 1.13 1,8 0.17 Rey Delay 3.22 (4.58) 4.44 (4.85) 1.56 1,8 0.25 Line Orientation 7.00 (4.89) 10.44 (7.94) 5.61 1,8 0.52 HVLT** 10.22 (4.38) 11.78(4.82) 17.04 1,8 0.33 HVLT Delay 2.00 (2.06) 2.33 (2.29) 4.00 1,8 0.15 Digit Forward 5.44(1.13) 5.67 (1.66) 1.00 1,8 0.16 Digit Backward 3.00(1.80) 3.22 (1.92) 1.00 1,8 0.11 Digit Symbol** 9.88 (9.40) 12.11(9.66) 16.50 1,8 0.23 Trails A 136.11(100.62) 133.78(101.60) 3.92 1,8 0.02 Trails B 273.67 (64.14) 270.89 (66.31) 3.87 1,8 0.40 GDS 23.56 (8.73) 20.67 (7.14) 5.26 1,8 0.36 Apathy* 25.11 (4.62) 23.44 (4.67) 6.67 1,8 0.35 IQCODE 64.56 (6.10) 65.22 (8.74) 0.27 1,8 0.08 Barthel** 39.44 (8.08) 42.78 (7.95) 25.00 1,8 0.41 DAD 17.11 (4.07) 16.56 (5.15) 0.14 1,8 0.11 * p< .05. ** p< .01. 61 Table 8. Improvement Scores for Test in which Both Groups Showed Improvements Change from Baseline Intervention Mean (SD) Control Mean (SD) Difference Between Group Mean (95% CI) p Animals 4.00 (2.39) .89 (.60) 3.11 (1.36,4.86) .002 HVLT 7.44 (2.55) 1.56(1.13) 5.89 (3.91,7.86) .001 Digit Symbol 14.11 (7.22) 2.22(1.64) 11.89 (6.66, 17.12) .001 Apathy -9.78 (5.72) -1.67(1.94) -8.11 (-12.38, -3.86) .001 Barthel 27.22 (13.72) 8.33 (5.00) 18.89 (8.57, 29.21) .001 Assessed for eligibility (n = 18) 18 randomly allocated 9 allocated to experimental group 9 allocated to control group Pre-treatment Outcome measures (n = 9) Pre-treatment Outcome measures (n = 9) Intervention: Conventional therapy with VS/VM training fn = 9) Control: Conventional therapy alone (n = 9) Post-treatment Outcome measures (n = 9) Post-treatment Outcome measures (n = 9) Figure 1. Study participant flow chart of enrollment and randomization Post-Intervention Group Differences x/x • Experimental • Control MMSE Boston REY Copy Naming HVLT Digit Backwaid Dgit Symbol DAD NeuropsychologicalTe st Figure 2. Comparing neuropsychological changes between groups from preintervention to post-intervention. Error bars represent standards error of the measurement. Post-intervention differences between the groups are seen in each neuropsychological domain. * p < .05. ** p < .01. 64 Comparison of Within Group Improvements 60 50 40 1 Experimental 30 2 Control 20 10 0 li 1 MMSE 2 M 1 2 Boston Naming 1 2 ReyCopy 1 • Pre-Intervention * Post-Intervention 2 Digit Symbol Neuropsychological Test Figure 3. Post-intervention differences between the groups in neuropsychological domains. Error bars represent standard error of the mean. Experimental group showed cognitive improvement whereas the control remained the same. *** p < .001. 65 Magnitude of Change from Baseline Between Groups 35 30 20 & 15 9 LJL_ •Experimental — u 10 5 0 • Control *** Animals HVLT Digit Symbol Apathy Brnlhel Neuropsychological Tests Figure 4. Comparing magnitude of neuropsychological change between groups from pre-intervention to post-intervention. Error bars represent standard error of the mean. Experimental group improved significantly more than the control group. * p < .05, **p<.01. 66 Experimental Group Pac-Man High Score 12000 10000 • Weeks 1-2 • Weeks 3-4 3 4 5 Participant Figure 5. Improvements in Pac-man high score from initial weeks to final weeks of training. Error bars represent standard error of the mean. Each participant significantly increased their high-score from initial weeks to final weeks of training. * p < .05, ** p < .01. 67 Experimental Group Average Length of Play on Pac-Man 70 60 50 72 "g 40 £ 30 o CO ** ** "Weeks 1-2 • Weeks 3-4 * liJii 20 10 0 1 2 3 4 5 6 7 8 9 Participant Figure 6. Participant improvements in Pac-man duration of play from initial weeks to final weeks of training. Error bars represent standard error of the mean. Each participant significantly increased duration of time played from weeks 1-2 to weeks 3-4. * p < .05, ** p < .01. 68 Experimental Group Block Design Completion Time • Weeks 1-2 a Weeks 3-4 Participant Figure 7. Participant improvements in block design duration of time from initial weeks to final weeks. Error bars represent standard error of the mean. Each participant showed faster assembly time from weeks 1-2 to weeks 3-4. * p < .05, ** p< .01. 69 Reference List Abbott, N. J., Ronnback, L„ & Hansson, E. (2006). 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