There is a growing body of research suggesting that the presence of psychopathic traits, and more specifically, callous-unemotional traits in youth, may constitute a distinct developmental pathway to aggressive behavior. However, ethnic groups are understudied in this literature such that it is unclear whether the correlates of psychopathic traits (i.e., violence, aggression, emotional processing deficits) are equally associated with these traits across different ethnic groups. Also, most theories on the development of psychopathy have provided biologically-based explanations for the cognitive-affective deficits that are considered to be core features of psychopathy. However, research suggests that exposure to adverse contextual environments is also associated with emotional processing deficits and could be important in the etiology of psychopathic traits. The current study examined callous-unemotional traits, emotional processing using the emotional pictures dot-probe task, and exposure to adverse contextual environments (i.e., community violence, abuse) in sixty African American and twenty Caucasian detained boys (n = 80). The results of the current study revealed that aggression, delinquency, and violence were associated with psychopathic traits and this did not differ across ethnic groups. Also, there was an interaction between psychopathic traits and aggression that supported past research and indicated that aggressive youth high on psychopathic traits showed a reduced responsiveness to distressing stimuli but aggressive youth low on psychopathic traits showed an enhanced responsivity to distressing stimuli. The association with contextual factors revealed that exposure to community violence was correlated with both psychopathic traits and emotional response to distress stimuli. There was also an interaction between psychopathic traits and exposure to community violence that was similar to the interaction found between psychopathic traits and aggression. That is, psychopathy was inversely related to emotional responses to distressing stimuli, but only for youth high on exposure to violence. Both of these interactions suggested that there was a group of youth high on callous-unemotional traits that also showed strong emotional responses to distressing stimuli. Analyses indicated that this group of youth experienced greater levels of abuse, consistent with research showing that abused children tend to be hypervigilant to emotional stimuli but may also show deficits in empathy. These findings suggest that there may be multiple developmental pathways to psychopathy and have important implications for how treatment approaches should be uniquely tailored to the needs of youth in each pathway.

Action control arises from the interaction of two anatomically distinct decision-making systems, namely goal-directed and habitual behaviour. Goal-directed behaviour is characterized by the consideration of future choices and respective outcomes whereas habitual responding is driven by stimulus-response associations. Response inhibition is essential for goal-directed behaviour and deficits are shown in impulsivity. We administered an acute clinically relevant dosage of the commonly used serotonin reuptake inhibitor escitalopram to sixty-six healthy volunteers in a double-blind, randomized, placebo-controlled design. We administered a large task battery in order to study the effect of escitalopram in several cognitive functions including response inhibition, learning and affective processing. We found dissociate effects on cognitive aspects possibly mediated by distinct cortico-striatal loops. Acute escitalopram administration had a beneficial effect on action cancellation, one aspect of inhibitory control, without any effect on action restraint or waiting impulsivity. The treatment resulted in impaired performance in a probabilistic reversal-learning task and increased sensitivity to misleading feedback thus leading to maladaptive performance. An extra-dimensional set shift impairment during an attention set shift task and a tendency towards impaired instrumental learning discrimination were also observed in the escitalopram group. Our results are discussed in the context of well-documented effects of the dopaminergic system and suggestions of opponent interaction of serotonin and dopamine.

Despite extensive evidence documenting abnormal hypothalamic-pituitary-adrenal (HPA) axis functioning as a risk factor for the development of depression and other psychiatric disorders, and experimental evidence from acute stress manipulations, the effects of sustained cortisol alterations on clinically relevant cognitive-behavioural and neural processing remain poorly understood. The aim of this thesis was to characterise how non-acute changes in cortisol levels modify behavioural and neural biases implicated in stress-related disorders by following two complementary lines of evidence: firstly, by increasing cortisol via a direct pharmacological intervention; and secondly, by testing the ability of gut microbiota manipulations to alter cortisol reactivity. The first study found that sustained increases in cortisol following 10-day administration of hydrocortisone were associated with altered memory and emotional processing in healthy volunteers. Specifically, participants receiving hydrocortisone showed enhanced recognition of emotional words, while their neutral memory performance was unaffected despite lower parahippocampal and occipital activation during viewing and encoding of neutral pictures. Furthermore, we found that resting-state functional connectivity between limbic-temporal regions of interest (amygdala and hippocampus) and the striatum (head of the caudate), as well as frontal and prelimbic cortices was decreased. In contrast, hippocampal and visual processing during negative facial expressions, and functional connectivity between the amygdala and the brainstem at rest, were increased in the hydrocortisone versus placebo groups. Overall, these findings suggest that non-acute increases in glucocorticoids enhance processing of emotionally salient information in limbic-temporal regions, which may modulate further neural mechanisms of sensory and homeostatic relevance. Enhancements in declarative emotional memory following hydrocortisone also implicate the modulation of amygdalar-hippocampal interactions by cortisol. Conversely, neutral stimulus processing was found to be either reduced or unaffected across a number of cognitive and memory domains. A specific increase for negative processing was further supported by poorer self-reported well-being at the mid-point of the study in participants receiving hydrocortisone. In a separate study exploring the ability of prebiotic supplements to affect cortisol reactivity and emotional processing, a Bimuno-galactooligosaccharide prebiotic was found to reduce the waking cortisol response and increase positive versus negative attentional processing in healthy volunteers. While these effects were not found to be associated, they provide initial promising evidence of the ability to target the HPA axis and emotional processing via the gut microbiota in humans. Overall, this thesis supports the idea that stress-induced physiological changes after prolonged or repeated cortisol exposure are associated with neural and behavioural alterations, which in turn have been crucial in understanding neuropsychological mechanisms underlying psychiatric disease. A better stratification of the effects of sustained HPA axis alterations on psychiatrically relevant cognitive-emotional domains and neural mechanisms thus remains of high priority.

Increased attention towards threatening stimuli in both the external and internal environments is thought to be a factor in the causation and maintenance of pathological anxiety. Attentional biases for threatening information have been demonstrated in anxiety disorders, however the cortical mechanisms involved remain unclear. In this investigation, an Emotional Stroop task consisting of neutral, positive, depression-related and anxietyrelated words, was used to investigate attentional biases in 14 Panic Disorder patients and 32 psychiatrically healthy controls. The standard colour-word Stroop was also performed to determine whether any general cognitive deficits exist in Panic Disorder. Steady-state probe topography (SSPT), a brain electrical activity imaging methodology, was used to investigate participants' brain activity during performance of the tasks. It was hypothesised that Panic Disorder is associated with specific biases for disorder-specific information and thus patients would exhibit increased interference for anxiety-related words only, compared to neutral words. Mean reaction times for the Standard Stroop was similar for the two groups. For the Emotional Stroop task, neither group showed an interference effect for any emotional category. However, Panic Disorder patients performed the Emotional Stroop significantly more slowly than the Controls. The SSPT data suggest that the Standard and Emotional Stroop tasks are associated with different patterns of brain activity in the Control and Panic Disorder groups despite the similarities in the reaction time data. Specifically, the Standard Stroop was marked by strong temporo-parietal excitation in the Panic Disorder group only. In addition, anterior SSVEP patterns further differentiated between the Control and Panic Disorder groups. The most striking finding for the Emotional Stroop was strong sustained bilateral temporo-parieto-occipital excitation in the Panic Disorder group. In addition, a subgroup of the Controls exhibited increased interference for anxiety-related words and therefore the brain activity for this group and the remainder of Controls who did not show interference was analysed separately. It was found that the presence of interference for anxiety-related words was associated with right prefrontal inhibition prior to response. Other time-varying changes in the SSVEP further distinguished between the subgroup of Controls who showed an interference effect and those who did not.

The aim of the current study was to test the effectiveness of the written disclosure paradigm on psychological health, cognitive processing, dispositional and social factors and to improve the paradigm on the basis of the underlying mechanisms responsible for its benefits. Participants consisting of 73 Middle East Technical University students were randomly assigned to one of three groups to write during 30-min sessions on 3 consecutive days: (1) Guided Disclosure Group (GDG) / (2) Standard Disclosure Group (SDG) / (3) Control Group (CG). GDG wrote about their most upsetting life events according to exposure, cognitive reappraisal, and benefit-finding instructions, respectively. SDG wrote about their deepest thoughts and feelings related to their most upsetting life events. CG described familiar environments without including any emotion or opinion. All participants completed measures of psychological health (i.e., general psychological distress symptoms), cognitive processing (i.e., intrusive thoughts, avoidance, and appraisal of the event), dispositional (i.e., trait anxiety, alexithymia, coping styles) and social factors (i.e., perceived social support, and severity of negative life events) prior to the first writing session, following the third writing session, and a 1-month follow-up. It was expected that GDG would report more improvements in outcome measures, relative to SDG. In turn, SDG was expected to display greater improvements, relative to CG. All groups reported similar improvements in psychological distress symptoms, cognitive processing and alexithymia. The findings were discussed in terms of relevant literature.

Childhood emotional maltreatment is associated with damaging consequences, although relatively little is known about the mechanisms underlying its effects. This dissertation investigated the concurrent influences of adult attachment and mindfulness on internalizing symptoms and emotional processing in young adults with and without a history of emotional maltreatment. Study 1 revealed that a sequential mediation model, with adult attachment orientations as first-step mediators and mindfulness as a second-step mediator, fit the data better than a simultaneous mediation model. In addition, moderation analyses revealed that high self-reported levels of mindfulness protected against the development of internalizing symptoms, even in at-risk individuals. Study 2 replicated these findings in a new sample, while also extending the results beyond a self-report outcome, using behavioural measures of emotional processing. Emotional maltreatment, adult attachment, and mindfulness predicted the amount of perceptual information required to correctly identify fearful faces and the amount of interference demonstrated in response to positive and negative emotional words. Cumulatively, these findings suggest that childhood emotional maltreatment can disrupt attachment relationships and encumber the development of mindfulness, contributing to internalizing symptoms and the biased processing of emotional information. However, alternative outcomes are possible, given the presence of high levels of mindfulness and secure attachment representations. This has implications for clarifying developmental theories and evaluating clinical interventions that may mitigate the negative effects of childhood emotional maltreatment.

On évoque souvent des difficultés à interagir socialement chez les enfants ayant une dysphasie. Ces difficultés sont généralement attribuées aux troubles du langage, mais elles pourraient aussi provenir d’un problème à décoder les émotions des autres. Le but de la présente recherche est d’explorer cette voie chez les enfants dysphasiques de 9 à 12 ans. Différents stimuli émotionnels leur ont été présentés sous forme de vidéos ainsi qu’à des enfants d’un groupe contrôle selon cinq conditions : parole non filtrée, parole filtrée, visage dynamique, visage dynamique accompagné de la parole non filtrée, et visage dynamique avec parole filtrée. Les enfants dysphasiques et les enfants du groupe contrôle ne se comportent pas différemment de manière significative en fonction des émotions présentées et des conditions testées. Par contre, un sous-groupe d’enfants ayant une dysphasie mixte commet significativement plus d’erreurs pour l’ensemble de la tâche que le sous-groupe d’enfants sans dysphasie de même âge chronologique. En fait une part seulement des enfants dysphasiques mixtes ont des scores plus faibles. Ces mêmes enfants présentent un QI non verbal faible tandis que leur compréhension du langage est équivalente à celle de leur sous-groupe (enfants dysphasiques mixtes). Malgré ces différences significatives, les scores des enfants dysphasiques mixtes restent relativement élevés et les difficultés observées sont subtiles. Sur le plan clinique, les praticiens (orthophonistes, psychologues, éducateur) devront systématiser l’évaluation des habiletés de décodage des émotions chez l’enfant dysphasique dont les difficultés ne sont pas forcément évidentes dans la vie quotidienne. La recherche devra développer un outil de dépistage sensible aux troubles de décodage émotionnel et des stratégies thérapeutiques adaptées. / Children with Specific Language Impairment (SLI) can have social problems that are often explained by their language disorders. However, the ability to identify other people’s emotions could be caused by their emotion processing difficulties. We explore this question in children with SLI aged 9 to 12 years old. Children with and without SLI were tested on five emotional stimuli presented in dynamic video and audio format: unfiltered speech, filtered speech, facial expressions, facial expressions with unfiltered speech, and facial expressions with filtered speech. The children with impaired language do not differ significantly from the unimpaired children across all modalities and emotions. However, a subgroup of SLI children with mixed (expressive-receptive) delay commits more errors on the task than their age-matched peers. In fact only a subgroup of these children shows lower scores. These same children also show low IQ scores but language comprehension as good as their subgroup. Despite these significant differences the mixed SLI group’s scores are quite high, showing that deficits are subtle. Clinical implications of this study militate for a systematization of the evaluation by health practitioners of these abilities in children with SLI who might not show obvious signs of deficits in this domain in their everyday activities. Research should pursue the development of a sensitive evaluation tool to identify emotional decoding difficulties and should evaluate therapeutic strategies adapted to this population.

Objective: Research has demonstrated deficits in socio-emotional processing following childhood traumatic brain injury (TBI; Tonks et al., 2009a). However, it is not known whether a link exists between socio-emotional processing, TBI and offending. Drawing on Ochsner’s (2008) socio-emotional processing model, the current study aimed to investigate facial emotion recognition accuracy and bias in young offenders with TBI. Setting: Research was conducted across three youth offender services. Participants: Thirty seven participants completed the study. Thirteen participants reported a high dosage of TBI. Design: The study had a cross sectional within and between subjects design. Main Measures: Penton-Voak and Munafo’s (2012) emotional recognition task was completed. Results: The results indicated that young offenders with a TBI were not significantly worse at facial emotion recognition compared to those with no TBI. Both groups showed a bias towards positive emotions. No between group differences were found for emotion bias. Conclusion: The findings did not support the use of Ochsner’s (2008) socio-emotional processing model for this population. Due to the small sample size, inadequate power and lack of non-offender control groups, it is not possible to draw any firm conclusions from the results of this study. Future research should aim to investigate whether there are any links between TBI, socio-emotional processing and offending.

Substance use disorders (SUDs) are a growing concern in today’s society. Substantial research has advanced our understanding of how cognitive control, reward processing, and emotional difficulties may contribute to the development and maintenance of SUDs; however, the impact of affective instability in SUDs has received limited attention. I sought to examine how different dimensions of affective instability interact to increase substance misuse, and to investigate the impact of affective instability and substance use on neural mechanisms of reward and emotion processing. Specifically, I was interested in two event-related potential (ERP) components, the reward positivity and the late positive potential (LPP), which respectively reflect the neural mechanisms of reward and emotion processing. Toward this end, I recorded the ongoing electroencephalogram (EEG) from undergraduate students as they navigated two T-maze tasks in search of rewards. Further, one of the tasks included neutral, pleasant, and unpleasant pictures from the International Affective Picture System (IAPS). Participants also completed several questionnaires pertaining to substance use and personality. A principal components analysis (PCA) revealed a factor related to affective instability, which I named reactivity. This factor significantly predicted increased substance use. Interestingly, individuals reporting higher levels of affective reactivity also displayed a larger reward positivity following stimuli with emotional content. The current study identified a group of high-risk substance users characterized by greater levels of affective reactivity and increased reward processing. It is my hope that these results further elucidate the complexities of SUDs and help to create efficacious, individually-tailored treatment programs for those struggling with SUDs. / Graduate

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