Limited data are available regarding the clinical utility of the Wechsler Memory Scale-III (WMS-III) Family Pictures (FP) subtest, yet it has received much criticism in the literature. Specific problems of the subtest that have been cited include the lack of clarity regarding the neuropsychological functions that significantly influence successful performance. The current study assesses the extent to which performance on the FP I and FP II subtests can be predicted by memory, visual ability, verbal ability, and executive functioning, in 454 outpatients from a neuropsychology clinic. Data from the Family Pictures I (FPI) and Family Pictures II (FPII) subtests, in addition to scores obtained from commonly used measures of memory, verbal, visual, and executive functioning were analyzed via hierarchical multiple regression analyses, co-varying for age and education. The current study also explores the extent to which the FP's individual components of character, location, and action load on factors of general verbal and visual-spatial abilities in a sample of 193 neuropsychology clinic outpatients. Results were obtained via three separate exploratory factor analyses (one for each FP component examined). Results of the multiple regression analyses indicated that FP I and FP II performance is best predicted by a mixed visual/verbal memory factor. Furthermore, the factor analyses revealed that all three components of location, action, and character load on a mixed general visual ability and general memory factor. These findings expand upon previous research by lending greater understanding of the skills needed for successful FP performance in neuropsychologically impaired populations.

The current thesis explores the complex relationship between cognitive control and memory. A series of experiments combined task-switching paradigms with recognition memory tests to measure how switching between tasks influences effective control over long-term memory. In these experiments, participants were presented with compound stimuli consisting of a picture and an overlaid word, and were cued in each trial whether the word or the picture was relevant (attended) or irrelevant (unattended). Participants were then tested for their memory of items presented during task switching. Experiments 1-2 indicated that switching between tasks reduces the selectivity of processing: Switching was associated with impaired task performance as well as more similar memory ratings for attended and unattended items. Experiments 3-5 extended these findings by showing that enhanced top-down control positively affected task-performance as well as memory, in both cases by increasing the selectivity of processing toward task-relevant information. Experiments 6-7 replicated key effects with simple switches of visual attention, and explored the neural correlates of successful task performance and encoding using EEG. The key finding here was that previously observed ―subsequent memory‖ effects reflect, at least in part, selective encoding processes. The last chapter extended the focus of the investigation to explore the role of control in long-term memory retrieval. FMRI meta- analyses indicated considerable overlap in neural activation found during task switching and during the adoption of different retrieval sets. The results of Experiment 8 indicated that switching during task performance and later memory retrieval were both associated with decreased selectivity of processing. Collectively, the results of this thesis suggest that selectivity of processing is a critical factor in effective task performance and successful memory, with potentially very similar mechanisms underlying the two. This work demonstrates the fruitfulness of combining research on cognitive control and memory to study questions relevant for both fields.

Pathological gambling is a maladaptive behaviour associated with diminished self-control over persistent compulsive gambling behaviour despite negative consequences. A significant revision to the clinical perspective of pathological gambling is underway, and the disorder will likely be recognized as a behavioural addiction in the fifth edition of Diagnostic and Statistical Manual of Mental Disorders. However, the neurobiological, cognitive and behavioural processes that drive a ‘behavioural addiction’ are unclear. A series of five studies were conducted to investigate cognitive mechanisms associated with neural and behavioural substrates of addictive processes in disordered gambling. Studies 1 through 3 investigated neurobiological correlates of addiction in individuals with pathological gambling as compared to individuals with cocaine dependence, and as compared to non-addicted healthy controls. Study 1 investigated brain activity associated with anticipatory and consummatory reward processing during slot-machine gambling. Study 2 investigated executive control processes by examining functional brain networks associated with loss-chasing behaviour. Study 3 employed voxel-based morphometry (VBM) to explore alterations in grey-matter volumes in individuals with addictive disorders. Studies 4 and 5 investigated the behavioural substrates of addiction in regular gamblers utilizing emerging and novel research techniques. Study 4 examined continuous hand motion trajectories to explore approach biases and implicit processing. Study 5 employed an adaptive testing methodology to explore the influence of gaming machine preferences on cognitive processes and gambling behaviour. Research identified neurobiological and behavioural substrates of gambling-related beliefs and biases that indicate significant contributions of cognitive mechanisms to the development and persistence of a behavioural addiction. Results suggest addictive disorders may share some common features of anticipatory reward processing and brain structure (Studies 1 and 3), while neural signals associated losing outcomes and decision-making during gambling may be specific to disordered gambling (Studies 1 and 2). Furthermore, cognitive distortions in regular gamblers may influence reinforcement and executive control processes (Study 4), and individual preferences for gaming speed may influence cognitions and behaviour during machine gambling. As additional psychological disorders are being considered for classification as behavioural addictions, and clinicians will be faced with the challenges of treating individuals with these non-substance-related addictive disorders, a better understanding of behavioural addictions, through the study of disordered gambling, will be essential under the new diagnostic framework.

Context-sensitive cognitive rehabilitation aims to address the specific deficits of patients by taking into account the unique strengths and weaknesses of each brain-injured individual. However, this approach requires customized assessments and trainings that are difficult to validate, time-consuming or simply unavailable for daily clinical use. Given the currently struggling economy and an increasing number of patients with brain injuries, a feasible and efficient solution for this individualized rehabilitation concept is needed. This dissertation addresses the development and evaluation of a VE-based training and assessment for context-sensitive cognitive rehabilitation. The proposed application is designed to closely resemble real-world places that are relevant to each individual neurological patient. Despite such an ecologically valid approach to rehabilitation, the application also integrates traditional process-specific tasks that offer potential for standardization and collection of normative data across patient populations. Three cognitive tasks (navigation, orientation, spatial memory) have been identified for use in individualized VEs. In three experimental trials the feasibility and validity of the technological implementation and theoretical foundation of these tasks has been assessed. In a fourth trial one of the tasks has been used for the rehabilitation of a brain-injured patient. Based on the results of these studies a workflow for the rapid development of VEs has been established which allows a VR developer to provide clinicians with individualized cognitive tasks. In addition, promising results for the clinical use and validation of the proposed system form the basis for future randomized controlled clinical trials. In conclusion, this dissertation elaborates how context-sensitive and process-specific rehabilitation approaches each offer a unique perspective on cognitive rehabilitation and how combining both through the means of VR technology may offer new opportunities to further this clinical discipline.

This project represents a descriptive study of 35 chronically mentally ill (CMI) adults enrolled in a community-based vocational rehabilitation program during the 1981 calendar year. As part of their first month in the program, subjects were administered a screening battery consisting of the Trail Making Test, Reitan-Indiana Aphasia Screening Test, Reitan-Klove Sensory Perceptual Examination, Valpar Independent Problem Solving Work Sample (IPSWS) and Wide Range Interest Opinion Test (WRIOT). Correlations were derived among these and with other variables, including the Work Adjustment Rating Form, schizophrenic versus nonschizophrenic psychiatric diagnosis, time in program and period of competitive employment resulting from program involvement. The issue of medication and its potential for impacting on subjects' performance in the program was also addressed. The neuropsychological measures in the battery were significantly correlated among themselves and discriminated between schizophrenic and nonschizophrenic CMI subjects in the sample with 100% accuracy. However, results on neuropsychological tests did not predict whether or not a subject would realize competitive employment during the year of the study. Both schizophrenic and nonschizophrenic subjects produced average performances in the impaired range of functioning according to published criteria for the neuropsychological instruments, although schizophrenic subjects consistently performed closer to the normal population. Vocational instruments included in the battery appeared to measure a more heterogeneous set of functions than the neuropsychological tests, and did not appear to represent a vocational factor. Two scores from these vocational instruments, Valpar IPSWS and WRIOT Negative Bias, were combined with Trail Making Test (Part A) scores in a discriminant function that classified subjects with 81% accuracy on attainment of competitive employment status. Over half (56%) of the people who participated for three months or more experienced some competitive employment, and 39% of those who completed three months or more were able to maintain full-time or part-time competitive employment for longer than 60 days. These results supported the effectiveness of Fountain House Model programs in achieving vocational rehabilitation goals with the difficult CMI population. Support was also provided for community-based research to study both social programs and their clientele.

Prior research suggests that aspects of self-knowledge are relatively intact in many memory-impaired patients with acquired brain injury. Therefore, cognitive strategies that rely on preserved mechanisms of the self may be particularly effective in this population. The three studies presented in this dissertation investigated the practical utility and mnemonic mechanisms of a novel cognitive strategy designed to capitalize on self-referential processing: self-imagination. Study 1 investigated the effect of self-imagining on cued recall in memory-impaired patients with acquired brain injury and healthy controls. Sixteen patients and sixteen healthy controls intentionally encoded word pairs under four separate conditions: visual imagery, semantic elaboration, other person imagining, and self-imagining. The results revealed that self-imagining enhanced cued recall more than the other encoding conditions in patients and healthy controls. Study 2 was an initial investigation of the effect of self-imagining on free recall. Twenty healthy adults intentionally encoded word pairs under four conditions: self-imagining, a self-descriptiveness task thought to rely on access to semantic information in self-knowledge, an autobiographical memory task requiring retrieval of a self-relevant episodic memory, and a structural processing task. The results demonstrated that self-imagining improved free recall more than the other encoding conditions in healthy adults. Study 3 investigated the effect of self-imagining on free recall in memory-impaired patients with acquired brain injury and healthy controls. Fifteen patients and fifteen healthy controls intentionally encoded personality trait adjectives under five conditions: a self-imagining task, a self-descriptiveness task, an episodic autobiographical memory task, a semantic elaboration task, and a phonemic processing task. The results revealed that the advantage of self-imagining over the other cognitive strategies extended to free recall in patients. Furthermore, the results indicated that the mnemonic benefit of self-imagining was partly attributable to preserved mechanisms associated with the retrieval of semantic information in self-knowledge. The findings from this dissertation indicate that self-imagining is a self-referential cognitive strategy that generates robust and reliable mnemonic improvement in memory-impaired patients with acquired brain injury and healthy controls. Cognitive strategies that involve preserved mnemonic mechanisms of the self, such as self-imagination, may provide a new direction in cognitive rehabilitation.

L’âge, le génotype et les traumatismes crâniens (TCC) sont trois facteurs de risque majeurs du développement de la maladie d’Alzheimer (MA). Avec une accumulation d’évidences démontrant la persistance d’anomalies cérébrales suite aux plus légers des TCC, qui affichent d’ailleurs la plus haute incidence, il devient impératif de tester l’hypothèse selon laquelle même les commotions cérébrales puissent interagir avec l’âge et les gènes afin de précipiter la neurodégénération. Trente ex-athlètes de haut niveau (âge M = 60 ans), dont la moitié a subi des commotions cérébrales il y a plus de 30 ans, ont été évalués en neuropsychologie, en neuroimagerie multimodale ainsi qu’en génétique. De nombreuses mesures neuroanatomiques, dont l’expansion du volume des ventricules latéraux, se trouvent à corréler avec divers déficits cognitifs (mémoire différée et de reconnaissance) détectés chez les participants commotionnés. D’un intérêt particulier, certains de ces résultats sont modulés par le polymorphisme nucléotidique simple du gène Apolipoprotéine E. Ces résultats appuient l’hypothèse selon laquelle la commotion cérébrale chez de jeunes athlètes serait un facteur de risque de neurodégénération dans le vieillissement normal. / Age, genotype and traumatic brain injury (TBI) are three of the most important risk factors of Alzheimer’s Disease. With a growing body of evidence showing the persistent deleterious effects of the mildest form of TBI, it becomes imperative to test the hypothesis that sports concussion could interact with aging to precipitate neurodegeneration. Thirty former high-level athletes (mean age = 60 yrs), half of them having sustained sports concussion during their young adulthood, underwent neuropsychological, neuroanatomical and APOE genotype examination. Data analysis revealed numerous neurobiological anomalies, such as ventricular enlargement, correlating with cognitive deficits (delayed and recognition memory) in concussed participants. Of particular interest, some neuroanatomical measures were found to be modulated by APOE single-nucleotide polymorphisms. These findings support the idea that sports concussions sustained in early adulthood are a risk factor of neurodegeneration in late adulthood.

Selective eating (SE) refers to an individual narrowing their range of preferred foods, resulting in a restricted food intake, high levels of rigidity and food refusal (Bryant-Waugh, 2000). SE is encompassed in the new Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-V) (American Psychiatric Association, 2013) category avoidant restrictive food intake disorder (ARFID). Such difficulties are common in children with an autism spectrum disorder (ASD) (Raiten & Massaro, 1986) and neuropsychological differences have been found in children with ASD (Hill, 2004). This research aimed to be the first to investigate whether a distinct neuropsychological profile exists in children and adolescents with SE and furthermore, whether aspects of the profile vary depending on whether the child or adolescent displays elevated autistic traits. A case series of 10 children between the ages of 8 to 13 years old were recruited. A well-established neuropsychological test battery, the Ravello Profile (Rose, Frampton & Lask, 2012), was modified and administered to assess visuospatial processing, central coherence, executive functions (including cognitive flexibility, inhibition and planning) and theory of mind abilities. The results demonstrated a high degree of variability across the group in terms of visuospatial processing and theory of mind, weak central coherence across all participants and otherwise relatively intact abilities in executive function domains. There were no substantive findings in relation to those children with elevated autistic traits although a trend toward visuospatial processing differences did emerge. This exploratory case series was the first attempt to describe a neuropsychological profile in SE, however the small sample size and high variability in the data meant that a distinct neuropsychological profile did not emerge. The results did however provide an initial indication of possible trends in strengths and weaknesses across neuropsychological domains in SE. These findings have implications for the assessment and treatment of SE difficulties.

Variability in neural activity has historically been treated as noise, in favour of deriving estimates based on central tendency (e.g., mean). Recently, researchers have shown that variability and mean confer different sources of information and that increased variability in neural activity is associated with superior behavioural performance and that it decreases during late-life. Although mounting evidence suggests that neural variability is beneficial, it is less clear whether these findings are driven by within- or between-person factors and whether they are apparent during higher-order cognitive tasks. Further, variability can be derived in several different ways, drawing into question its congruence across operationalizations. The present investigation sought to separate within- and between-person sources of variance in order to ascertain what was driving any observable effects in three operationalizations of cerebral oxygenation, computed based on central tendency (mean), variability (standard deviation) and signal complexity (multivariate multiscale entropy). 25 older adults (71-81 years of age) completed two tasks of executive functions while undergoing assessment using functional near infrared spectroscopy. Time-varying covariation models were employed to estimate the effects of cerebral oxygenation on behavioural performance, as well as the moderating effects of age and fall status. Findings suggest that mean and variability are differentially associated with behavioural performance and are increased in older adults at greater fall risk. Whereas mean based computations were positively associated with more accurate and faster responding, variability based computations were primarily associated with faster responding only and occurred in non-overlapping regions of prefrontal cortex. Future studies of neural variability may consider examining within- and between-person factors and operationalizing signal complexity in cerebral oxygenation over longer time periods to examine its effects over multiple time scales. / Graduate / drewh@uvic.ca

Sleep is a complex process: the timing of sleep is regulated by two systems (the sleep homeostat and the circadian clock) and there are many potential functions of sleep. The aim of this thesis was to investigate: the impact of light on the regulation of sleep timing (study 1) and the role of sleep in emotional processing (study 2). Study 1 used natural variations in environmental light levels at different geographical locations, to examine the influence of daily light irradiance on sleep timing and chronotype using the Munich chronotype questionnaire (MCTQ). 6443 students were included in this study from six universities from the northern and southern hemispheres. Students in southern hemisphere cities had earlier sleep timings than those in the northern cities. Daily irradiance was higher in the southern hemisphere cities. The amount of time spent outside, age and sex, but not daily irradiance, influenced sleep timings. Study 2 explored the impact of an analogue traumatic event (trauma film) in students who were either sleep deprived or not sleep deprived on intrusive memories ("flashbacks"), sleep physiology and the impact of an increased risk of a mood disorder on this relationship. In this study the sleep deprived participants (n=19) reported fewer intrusive memories to the trauma film than those not sleep deprived (n=22). A change in sleep physiology was observed in the first sleep period following the trauma film, which was more pronounced in the sleep deprived group: increased levels of arousal, REM density and activity in the occipital region. Only three participants at-risk of a mood disorder completed study 2: their data are presented as case studies. In conclusion this research has demonstrated that differences in sleep timings exist between cities in the southern and northern hemispheres and has confirmed that many factors can influence sleep timing. It has also been demonstrated that following a highly emotional event not sleeping may have a beneficial effect, which has implications for the treatment of people after trauma.