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Resilience implies the ability to quickly recover from a negative life event and adapt to changing situations. The goal of the current study was to explore the mechanisms underlying resilience, including the roles of cognitive emotion regulation (reappraisal) and cognitive flexibility. Although all aforementioned mechanisms were investigated, there was a particular focus on the relationship between resilience and "affective flexibility," a term used to describe cognitive flexibility in processing affective stimuli. In the current study, participants completed several self-report personality and behavioral scales, including measures of trait-resilience and cognitive reappraisal, a cognitive flexibility task, a working memory task and two novel affective flexibility tasks. Results showed that one of the two affective flexibility tasks was a valid measure of the affective flexibility construct; affective flexibility significantly predicted level of resilience above and beyond cognitive flexibility and working memory. Cognitive flexibility was also a unique predictor of resilience when controlling for affective flexibility and working memory. Cognitive reappraisal was positively correlated with resilience but it did not appear to mediate the relationship between affective flexibility and resilience. This study was the first to demonstrate that resilience is related to specific cognitive abilities rather than general executive functioning. It is also the first to introduce and operationalize the construct of affective flexibility and show that it is a distinct process from cognitive flexibility. Research limitations and future directions are discussed.

The purpose of the present dissertation was to shed light on the neurophysiological effect of regular consumption of low amounts of alcohol on two important aspects of executive functions, cognitive interference and response inhibition, using functional magnetic resonance imaging (fMRI) in a sample of young adults. Participants were recruited from the Ottawa Prenatal Prospective Study (OPPS), a longitudinal study that has collected data from participants from infancy to young adulthood, which permitted control of a number of potentially confounding drug and lifestyle variables. This allowed for investigation of the unique effect of alcohol use on executive functions. The dissertation itself is comprised of two original manuscripts: the first study compared low-level alcohol users to controls on performance of the Counting Stroop, a task of cognitive interference; and the second study compared users to controls on performance of the Go/No-Go, a task of response inhibition.Although the results of both studies found no performance differences between groups, low-level alcohol users had significantly more brain activation in several regions, including areas not typically associated with task processing, compared to irregular or non-drinker controls. This difference in neurophysiology may be reflective of compensatory strategies within the brain, whereby the recruitment of additional regions may be attempting to compensate for potential underlying deficits that occur with increasing cognitive demand. While further research is needed to validate this hypothesis, the present findings highlight the vulnerability of the developing brain.

Executive Function (EF) is a highly complex, interrelated set of the cognitive process composed of multiple components: attention (sustain and selective), cognitive flexibility, working memory, inhibitory control (simple and complex) and problem-solving skill. These skills play a crucial role in the development where deficit in EF could lead to academic failure and a lifelong dissatisfaction. Research has found integral relationship between EF and emotion regulation(ER) suggesting children with weak EF skills are likely exhibit weak ER abilities. The current study is aimed to evaluate the effectiveness of a curriculum-based intervention program designed to promote EF skills and through that, increase children’s ER abilities. Program design includes group and individual activities placed in play corners within classroom setting. Seventy-eight preschoolers from 3 Hong Kong nursery schools were divided into control and program group. A multi-informant pre- and post- program evaluation including teacher questionnaires and a battery of EF and ER tasks completed by participants was used. The program group completed a 20-weeks program delivered by trained classroom teacher. Program benefits are found in promoting working memory, inhibitory control, “Hot” EF problem-solving and cognitive flexibility skills. Improvements in ER abilities and decreased of overall emotion, and behavioral post-program is also found. The gains in ER are observed to be correlates with gain in problem-solving and inhibitory control of EF components. / published_or_final_version / Educational Psychology / Doctoral / Doctor of Psychology

Systematic review Executive dysfunction is commonly reported following stroke with most research in this area focused on frontal lobe lesions. A systematic review was carried out to evaluate the evidence of executive dysfunction following stroke as compared to control groups. It was found that executive functions are consistently impaired following stroke and is not limited to frontal lobe lesions. Processing speed, mental flexibility, attention and working memory impairments were found to be the most common executive functioning impairments following stroke. Given the impact executive dysfunction may have on successful rehabilitation, relationships, return to work and quality of life, a comprehensive assessment of such difficulties is important following stroke to aid in the development of appropriate and effective rehabilitation strategies. Future research should use larger samples and a wide range of measures to assess different aspects of executive functioning. Introduction Mood disorders and psychological distress are common following stroke, and depression and emotional lability have been studied extensively. There has, however, been little research into difficulties in emotion regulation following stroke and whether this is associated with emotional or cognitive difficulties. The current study investigated emotion regulation difficulties following stroke and their relationship with quality of life, executive functions, anxiety and depression. Method Fifty participants who had suffered a stroke and forty five age matched controls completed the Difficulties in Emotion Regulation Scale, the Hospital Anxiety and Depression Scale, the World Health Organization Quality of Life assessment – Brief version and the National Adult Reading Test. In addition individuals with stroke completed four measures of executive functioning – Color Trails Test, Verbal Fluency, Brixton Spatial Anticipation Test and the Hayling Sentence Completion Test. Results Individuals with stroke had significantly greater difficulties in emotion regulation compared to age matched controls and this was significantly associated with lower self reported quality of life and increased levels of both anxiety and depression. No significant associations were found between emotion regulation and executive functions or between executive dysfunction and lower self reported quality of life. Discussion The current study found evidence that individuals who have suffered a stroke have more difficulties in emotion regulation than an age matched control group. This is clinically important as emotion regulation difficulties are found in mood disorders and it may be that such difficulties precipitate and/or maintain depression following stroke. The absence of an association between difficulties in emotion regulation and executive functioning suggests that other factors may influence such difficulties, such as the trauma of having a stroke. Future research should explore emotion regulation difficulties further following stroke, particularly investigating whether the course of these difficulties changes over time and if they are linked to type of stroke or lesion location.

In the present set of experiments, we investigated the effects of age and COMT genotypes on traditional measures of executive functions, e.g., Wisconsin Card Sorting Test (WCST; Hart et al., 1988), a battery of executive functions based on the 3 factor model (shifting, updating, inhibition) described by Miyake et al. (2000) and developed at the University of Arizona (Alexander et al., 2012), and two fMRI tasks of executive functions (shifting, updating). The results of experiment 1 showed that COMT influenced performance on several traditional measures of executive functions, with Met homozygotes outperforming Val homozygotes. However, on the WCST we did not observe less perseverative errors in Met carriers as reported previously (Barnett, Jones, Robbins, & Muller, 2007; Bruder et al., 2005; Malhotra et al., 2002; Nagel et al., 2008). According to Miyake et al. (2000), however, such tasks as the WCST may actually involve multiple executive processes, making it difficult to tease apart the different types of executive functions being measured. Furthermore, COMT may be sensitive to some aspects of executive functions and not others. To this end, in experiment 2 we investigated associations between COMT and measures of executive functions from each of the 3 domains described in Miyake et al. (2000). According to the models proposed by Bilder et al. (2004) and Cools and D’Esposito (2011), the Val allele promotes cognitive flexibility, while the Met allele promotes cognitive stability. Contrary to what we expected, Met homozygotes actually performed better than Met/Val heterozygotes but no better than Val homozygotes on one measure of updating (flexibility). Upon closer examination of the processes involved in the updating task, however, the results may not necessarily be contradictory as the task may have required greater stability than previously thought. In the fMRI experiment, although behavioral performance was largely similar between age groups and COMT genotypes on the fMRI tasks, we observed differences in activation such that younger adults and Met homozygotes showed higher levels of activation relative to older adults and Val carriers, respectively. Our results suggest that these higher levels of activation may have been relied upon to maintain similar levels of performance. Additionally, across the 3 experiments the effects of COMT indicate that an overall Met advantage cannot be assumed. Rather, the benefits of one allele compared to the other should be investigated in terms of the specific cognitive processes involved in the task at hand. Thus, it is important for future studies to continue characterizing the unity and diversity of executive functions and investigate factors that may influence these patterns behaviorally and neurally, such as age and genetics.

The aim of this study was to investigate the effects of acute stress on parallel task performance with the Game of Dice Task (GDT) to measure decision making and the Stroop test.  Two previous studies have found that the combination of stress and a parallel task with the GDT and an executive functions task preserved performance on the GDT for a stress group compared to a control group.  The purpose of this study was to create and use a new parallel task with the GDT and the stroop test to elucidate more information about the executive function contributions from the stroop test and to ensure that this parallel task preserves performance on the GDT for the stress group.  Sixteen participants (Mean Age: 26.88) were randomly assigned to either a stress group with the Trier Social Stress Test (TSST) or the control group with the placebo-TSST.  The Positive and Negative Affect Schedule (PANAS) and the State-Trait Anxiety Inventory (STAI) were given before and after the TSST or placebo-TSST and were used as stress indicators.  The results showed a trend towards the stress group performing marginally better than the control group on the GDT but not significantly.  There were no significant differences between the groups for accuracy on the Stroop test trial types.  However, the stress group had significantly slower mean response times on the congruent trial type of the Stroop test, p < .05, though.  This study has shown further evidence that stress and a parallel task together preserve performance on the GDT.

Schizophrenia is the ninth leading cause of disability worldwide (e.g., Lopez et al., 2006), and is a devastating psychiatric illness. Although diagnosis is made based upon the occurrence of positive and negative symptoms (First, Spitzer, Gibbon & Williams, 1995), it is the cognitive symptoms that are most strongly associated with functional outcome (Green, 1996 ). Cognitive control, including the ability to appropriately update relevant information and resist interference from irrelevant information, is critical for flexible and adaptive goal-directed behavior, and is among the most frequently noted of the cognitive symptoms in schizoprenia (Barch, 2005; Barch & Smith, 2008). Despite this, deficits in cognitive control are unaffected by medications used to treat the clinical symptoms of the disorder (Greene et al, 2008). Understanding both the behavioral and the neural mechanisms that comprise this deficit is thus of paramount importance. Although deficits in cognitive control in schizoprenia have been extensively studied, a number of questions still remain. Here, I ask two main questions: First, is cognitive control impaired globally, or are only certain aspects of cognitive control impaired in schizophrenia? I found that that there are (at least) two different selection mechanisms, and that people with schizophrenia are impaired in only one of these: dysregulation in left posterior ventrolateral prefrontal cortex correlates with impaired behavioral performance on a working memory task, suggesting that deficits in inhibiting irrelevant information from working memory is the crux of the deficit. Second, I asked whether the nature of the information affects cognitive control. I found that people with schizophrenia are able to deploy cognitive control processes more effectively than healthy controls in cases in which salient, emotional information competes with active cognitive goals, suggesting specific underlying deficits in emotional processing.

Thinking about the future can take numerous forms, varying from planning actions to foreseeing possible scenarios by means of knowledge and informed guesses, or speculations and intuitions, or imagination and creativity. Different cognitive processes are needed for each of these different types of future thinking. This thesis encompasses a series of experiments both on healthy volunteers and on brain damaged patients, revolving around the issue of "Future Thinking" (FT) that is the cognitive ability, specifically human, of envisaging one's own future. The concept of FT and the relevant literature are presented and discussed in Chapters 2 and 3. The ability to foresee has been normally assumed to rely on the reconstructive nature of episodic memory. This hypothesis is investigated in Chapters 4, 5 and 6. In these chapters data on young adults, who mentally pre-experienced autobiographical episodes, are presented to investigate which type of cue would elicit richer visualizations and to explore possible differences between temporal and a-temporal scene construction. The findings from these experiments on healthy volunteers call for a deeper understanding of the relationship between past experience and FT. Chapter 7 discusses results revealing that aMCI patients produced fewer episodic but more semantic details for both past and future events, as compared to controls, suggesting that reminiscence and FT are the expression of the same neurocognitive system. However, contrary to what was generally thought, data on patients with Parkinson Disease with spared memory performance reported in Chapter 8 and 9 show that FT is not entirely dependent on memory (and the hippocampus), rather the results suggest that poor performance in FT is associated with poor executive control. In Chapter 10 two patients affected by dense amnesia are investigated. Chapter 11 presents a single case exhibiting florid confabulation. The results confirm that although amnesia is associated with poor performance on FT, memory deficits cannot account for the entire picture of FT deficits. Indeed, dysexecutive symptoms play an important role in eliciting FT deficits.

Background: Conversation is the archetypal mode of communication. As a process it draws on numerous skills, and predispositions, adapting to dynamic contexts and coordinated in highly sophisticated ways for successful interaction. The combination of these abilities with contextual variables coalesces uniquely to represent what this research proposes to be conversational intelligence. It is argued here that high levels of conversational intelligence rest to a large degree on executive functions (EF) which are steadily becoming more widely acknowledged and researched within the communication domain. The impairment of EF in neurologically injured individuals has significant, though as yet undisclosed, repercussions for recovery, response to therapy and ability to integrate communication skills in every day interactions to support conversational success. This study incorporates some new approaches to the study of communication disorders following stroke, including conversation, executive functions and the possibility of pharmacological intervention. Aims: The aims of this study were to describe in detail the language, executive function and conversational characteristics of ten individuals who had experienced strokes and to examine the relationships among these three areas of functioning. In addition, this research investigated the response of these ten participants to pharmacological therapy on a one month trial of Leviteracetam (LEV). Methods and Procedures: Ten individuals who had suffered single incident strokes were recruited from local community and rehabilitation facility referrals. All ten participated in a four stage randomised, double blind investigation including baseline, active, placebo and withdrawal phases. At each stage participants underwent testing on an EF battery and were recorded having conversations with familiar interlocutors. In addition, significant others completed a rating scale assessing affective features and behaviours and language testing was conducted at the baseline phase using the WAB. The language and EF data were scored and the conversations subjected to Conversation Analysis. For each participant, profiles were created and assessed for interrelationships between the executive characteristics and conversational features representative of each executive construct. Repeated measures analysis of variance was conducted on EF data for the four phases of the study to determine significant pharmacological effects. Outcomes and Results: The majority of the sample presented with significant EF deficits across most areas assessed. Two participants presented with essentially intact profiles which were not explained in terms of types of aphasia or site of lesion. Language results proved to be inconsistently associated with EF deficits, but conversational features reflected underlying executive strengths or deficits with greater consistency. Two participants experienced amelioration (though not statistically significant) of interference control during the active phase, with observable improvements in conversational skill. One participant demonstrated improved conversation without a change in EF scores. The response to LEV is evaluated with reference to potential alternatives. Conclusions: The existence of EF deficits in individuals with stroke is demonstrated. Furthermore, the impact of these impairments is considerable and observable during naturally occurring conversations, suggesting the centrality of the EF contribution to conversational intelligence. The lack of association between formal language test scores and EF impairments argues for the inclusion of more authentic assessment approaches for stroke patients. The data is explored in terms of specific consequences of different lesion sites on EF and communication and briefly addresses bilingualism as a potential variable in explaining some of the variations in the data. Pharmacotherapy is addressed as an important focus of future research protocols. Implications for assessment and treatment are discussed as well as proposals for future study.