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A hypothesised association between personality and emotional processing was investigated within the framework of Cloninger’s psychobiological theory. According to this model, personality development is based on the interaction between two domains: temperament and character. A non-experimental, correlational design was applied, using existing data from a sample of 630 South African first year psychology students who completed the Temperament and Character Inventory (TCI) and the University of Pennsylvania Computerised Neuropsychological Test Battery (PennCNP). Canonical correlation analysis yielded significant associations between character variables Self-Directedness, Cooperativeness, and Self-Transcendence as measured and defined by the TCI and items from Penn Facial Memory Test (CPF) and Penn Emotion Discrimination Task (ED40), respectively. In this exploratory study participants lower in Self-Directedness and Cooperativeness were more efficient in facial recognition compared to participants higher in these dimensions. Conversely, individuals higher in Self-Directedness and Cooperativeness were more accurate in the discrimination of happy and sad emotions, respectively. Participants with higher Self-Transcendence performed better in facial recognition but were less accurate in discriminating between happy and sad faces. These results affirm the importance of further research into the association between temperament and character and emotional processing. / Dissertation (MA)--University of Pretoria, 2013. / gm2013 / Psychology / unrestricted

In light of collated research linking temperament traits and executive performance, the aim of this study is to explore, in a large non-clinical sample, the differences in executive performance profiles among participants with different intensities of the trait Novelty Seeking (NS). A further aim is to establish which facets of NS contribute to these differences. The NS temperament dimension and its subscales were operationalised as scores on the Temperament and Character Inventory (TCI), which is based on the psychobiological theory of personality. The University of Pennsylvania Computerised Neuropsychological Test Battery (PennCNP) of executive functioning (EF) and abstract reasoning was used to measure participants’ neuropsychological EF. The total sample of participants (n= 461) was divided into high NS (n= 216) and low NS (n= 245) groups to investigate any significant differences between them. Further analysis was then conducted in order to analyse the relationship between the NS scale, the four subscales (Exploratory Excitability, Impulsiveness, Extravagance, and Disorderliness), and performance in executive tasks. The findings of this study indicated significant differences between groups with different intensities of NS, with the high NS group functioning notably better in performance and reaction time. Furthermore, this study showed that facets of NS, such as impulsiveness was a significant contributor to EF performance outcomes. / Dissertation (MA)--University of Pretoria, 2013. / Psychology / unrestricted

The present investigation involved the development of a psychobiologic profile of individuals who experience exercise-related mood-enhancement and those who do not. The sample (N=301) consisted of students participating in 10-week exercise classes at North Texas State University. All subjects completed pre-test inventories assessing various psychological (i.e., trait anxiety and depression, attitude toward physical activity, self-estimation of physical ability and attraction to physical activity, expectancies of health benefits from exercise, and self-motivation) and biological (i.e., aerobic capacity and body fat percentage) variables. Trait anxiety and depression were also assessed before and after the 10-week exercise program and state anxiety and depression were assessed on an acute basis on two separate occasions during the program. Multivariate analysis of variance and discriminant function analysis were employed to determine which variables maximally discriminated between individuals who experienced mood-elevations following exercise and those who did not enjoy such rewards. The hypothesis that these two groups of individuals differ significantly from each other was not upheld by the results; thus, an overall psychobiologic profile could not be developed. However, the data did reveal that individuals who held a more positive attitude toward physical activity for the purpose of health and fitness reduced their state anxiety and depression following exercise significantly more than individuals who held more neutral attitudes. The results also confirmed previous research that individuals initially high in trait anxiety and depression showed a significantly greater decrease in these traits than subjects scoring in the low-moderate range at the outset of the exercise class. Recommendations for future research are discussed.

Previous studies have suggested that mechanisms for neural compensation involve a reorganisation to right hemisphere processing in people with post-traumatic stress disorder (PTSD), and are associated with functional alterations in the capacity for behavioural flexibility. However, research has not established a direct relationship between the complex physiological and psychological processes of the heterogeneous disorder and right hemisphere cortical activity. The present study examined cognitive information processing in people with PTSD, reaction patterns associated with perceived traumatic stressors, and quantitative electroencephalographic (qEEG) indices of hemispheric asymmetry. Individuals with PTSD (N=34) and age and sex-matched normal controls (N=136) completed standardised web-based self-report questionnaires assessing traumatic stressor events and reaction patterns to those events. Neuropsychological indices of verbal, visuospatial, sensori-motor performance, and electrophysiological recordings, were examined for right hemisphere coding. The relationships among traumatic characteristic reaction patterns of numbing and avoidance, cognitive performance, and frontal and posterior EEG alpha asymmetry were also investigated. Structural and functional alterations were shown in those with PTSD, using indices of working memory for the retrieval of verbal and psychomotor information, indicating a reduced speed of processing and alterations to background cortical arousal in left hemisphere frontal regions. The study supported and extended previous findings of verbal working memory abnormality, alterations to left frontal cortical rhythmic oscillations, and low EEG alpha amplitudes in those diagnosed with PTSD. Results indicated a pattern of compensatory mechanisms associated with reduced speed of information processing and right-sided activation patterns in PTSD participants and control participants who experienced strong reactions to perceived traumatic events. Findings support the impact of traumatic events on psychobiological health in high-risk populations, implicating an association with specific patterns of neural and cognitive functioning in characteristic numbing and avoidance behaviours. / Thesis (Ph.D.) -- University of Adelaide, School of Population Health and Clinical Practice, 2008

Les pensées humaines changent constamment : on regarde, on se souvient, on prévoit... Mais comment les gens accèdent-ils à cette succession de leur propres pensées ? Cette thèse a étudié l’introspection de la dynamique des pensées en capitalisant sur le phénomène saillant et surprenant de la rêverie éveillée (Chapitre 1). Les rêveries sont ces pensées spontanées à propos de nos préoccupations personnelles. Je décris d’abord comment des fluctuations lentes permettent de prédire ces épisodes de rêverie (Ch. 2, 3). Mais ces dynamiques pourraient aussi déterminer le contenu et l’introspection des pensées. En effet, les patients avec des troubles de l’attention (TDAH) rapportent plus de pensées “vides” : ce qui pourrait venir de troubles de la dynamique et/ou de l’introspection de leurs pensées (Ch. 4). Par ailleurs, deux expériences et une étude sur smartphone suggèrent que le langage intérieur facilite la conscience de la rêverie (Ch. 5). Le langage contribue aux capacités de contrôle : les pensées verbales pourraient donc être plus stables et plus vives. Finalement, je suggère que la détection des pensées n’est pas un accès direct à des éléments bien définis. Il s’agirait plutôt d’un mécanisme décisionnel ajustable, qui s’applique à des variables internes continues et dynamiques, comme dans la perception où une décision s’applique à des variables externes (Ch. 6). En somme, ces études jettent une lumière nouvelle sur l’introspection humaine et retrouvent des intuitions anciennes (Ch. 7). En effet, nos données appuient une proposition philosophique faite il y a 125 ans par William James, un des pères fondateurs de la psychologie scientifique : nos pensées sont un flux continu, et détecter la rêverie dépend aussi des dynamiques de ce flux. / Humans’ conscious experience is always changing: now seeing, now remembering, now planning. Yet, how people notice the unfolding of their own thoughts remains unclear. The present thesis studied the dynamics and introspective monitoring of thoughts, by capitalizing on the salient and often unnoticed phenomenon of mind-wandering (Chapter 1). Mind-wandering is the rise of thoughts about personal concerns. Against the idea that this rise is unpredictable, I first describe the characteristics of slow rhythms that predict mind-wandering occurrences during goal-directed tasks (Ch. 2, 3). Interestingly, these dynamics may determine thought content and introspection. Indeed, patients with Attention deficits (ADHD), who would likely experience alterations in both the dynamics and introspection of mind-wandering, report more “empty thoughts” (Ch. 4). Also, two experiments and a study using smartphones suggest that inner speech facilitates awareness of mind-wandering (Ch. 5). Inner speech contributes to monitoring capacities, thus verbal thoughts could be better sustained in time, increasing their vividness. Finally, I suggest that the detection of inner thoughts is not a direct access to clear-cut elements, but rather an adjustable decision mechanism applied to internal continuous and dynamic variables, similar to what happens in perception (Ch. 6). In sum, these studies shed a new light on human’s introspection and confirm old insights (Ch. 7). Indeed, they provide empirical support to a philosophical claim made 125 years ago by William James, one of the fathers of scientific psychology: we experience a continuous stream of thought, and detecting mind-wandering may depend on these dynamics.

The purpose of this study is to explore the differences within specific temperament traits on emotional processing bias. Participants with extremes in temperament traits Harm Avoidance and Novelty Seeking were categorised and their performance on a computerised neuropsychological test battery was investigated. First year psychology students at a residential university in South Africa were invited to participate in the original study. Processing of the data yielded a realised sample of 431 participants who completed the Emotions battery, which comprised of four tasks. The results show that processing of affective valence varies according to individual differences within specific temperament traits. The findings suggest a negative emotion processing bias in the High HA group in comparison to the low HA group. Furthermore, the impulsive and extroverted High NS group show an increased ability to process emotional faces in comparison to the low NS group. The implications of these findings are discussed in the context of putative risk factors for psychopathological disorders. / Dissertation (MA)--University of Pretoria, 2013. / Psychology / unrestricted

This study investigated the psychobiological and pacing characteristics of the 1.5 mile run. Sixty-six males (18-27 years) performed the run, and were monitored for ratings of perceived exertion, heart rate and split times. The perceived exertion values increased in a near-linear fashion inconsistent with other measures, and thus are not considered a supportable indicator of physiological performance during the run. Pace was characterized by an initial sprint that slowed to a near-steady pace and concluded with a final sprint. The initial and final sprints were most highly related to the variance of performance time. Initially, heart rate accelerated greatly. This acceleration slowed, ending in near-maximum heart rates. The data suggested that performance may rely heavily upon anaerobic mechanisms, and that variance in previously reported correlational analyses of VO2max and 1.5 mile run performance times may be somewhat due to anaerobic mechanisms.

Despite emergent attempts to connect temperament to a neurobiological etiology there has been little research that focuses on the relationship between temperament and character and neuropsychological test performance. Therefore, the aim of this study is to explore the relationship between temperament, character and performance on neuropsychological tests of executive functioning. Temperament and character dimensions were operationalized according to the Temperament and Character Inventory (TCI), a 240-item measure that is based on the psychobiological theory of personality. Neuropsychological performance was measured on the University of Pennsylvania Computerized Neuropsychological Test Battery (PennCNP), which is a test of executive functioning and abstract reasoning. The PennCNP comprised a test of Motor Praxis (MPRAXIS), the Penn Abstraction, Inhibition and Working Memory Task (AIM), the Letter-N-Back (LNB2), the Penn Conditional Exclusion Task (PCET), the Penn Short Logical Reasoning Task (SPVRT) and the Short Raven’s Progressive Matrices (SRAVEN). The sample comprised 422 first year psychology students at a residential university in South Africa. The results from this explorative study showed a moderate relationship between temperament, character and executive functioning. The temperament dimensions Novelty Seeking and Reward Dependence were positively related to AIM-NM, AIM and SPVRT, and inversely related to MPRAXIS. These results validate the importance of research that investigates the relationship between temperament and character dimensions and neuropsychological performance. / Dissertation (MA)--University of Pretoria, 2012. / Psychology / unrestricted

Features of impulsivity underlie multiple psychological disorders. The body of work examining impulsivity has largely focussed on self-report measurement and has incorporated psychological constructs without reference to the broader biological factors that may influence impulsive behaviour. Two studies were conducted to examine whether environmental stress and genetic status associated with dopaminergic and serotonergic function (DRD2, ANKK1 and 5HT2AR genotypes) were predictive of dimensions of impulsivity and risky behaviour (alcohol use). The two studies used a multi-method approach in a non-clinical community sample of young adults (aged 17-25 years). Dopamine is integral to the two leading theories of impulsive personality, Gray's Reinforcement Sensitivity Theory and Cloninger's Psychobiological model of personality. Dopamine plays a crucial role in reward reinforcement circuits in the brain. The A1 allele of the ANKK1 gene (also referred to as TaqIA of the DRD2 gene region) and the CC genotype of the C957T polymorphism of the DRD2 gene have both been associated with reduced D2 dopamine receptor density in key structures linked to brain reward. In addition, a strong body of evidence implicates their involvement in a number of clinical disorders associated with impulsivity. Serotonin function has also been associated with impulsivity in Cloninger's theory and there is also evidence of associations of two polymorphisms of the 2A serotonin receptor gene (5HT2AR T102C and -1438A/G SNPs) with impulsivity. Acute and chronic forms of stress are also important correlates of impulsive behaviour and the two studies directly examined the relationship between genotype, stress and impulsivity. Study 1 (N=180) utilised a cross-sectional design and examined interactions between these polymorphisms and chronic stress exposure on key impulsivity dimensions of reward sensitivity, Novelty Seeking and rash impulsiveness. Participants completed psychological questionnaires measuring chronic stress, dimensions of impulsivity, mood and substance use and provided mouth swab samples of buccal mucosal cells for DNA analysis. The study confirmed the association between A1 and CC allelic status and chronic stress being associated with harm avoidance and sensitivity to punishment. This suggests a role for both dopamine and background stress in impulsive behaviour. Study 2 (N=73) built upon this questionnaire research in the laboratory by utilising experimental psychological paradigms of impulsive behaviour and experimentally manipulating acute stress. Study 2 employed a mixed experimental design with a sub-sample of those studied in the cross-sectional sample. These behavioural paradigms included pre- and post- stress induction administration of the Card Arranging Reward Responsiveness Objective Test (capturing behavioural approach in the presence of reward cues, presumed to reflect reward sensitivity) and post-induction delay discounting and response inhibition measures. Study 2 confirmed the role of one of the two dopamine-related polymorphisms, with those with A1+ allelic status demonstrating lower reward responsiveness prior to rest or stress induction, which was overcome in the second administration of this task, independent of environment. A1+ allelic individuals also demonstrated significantly poorer response inhibition independent of stress, further confirming the association between A1+ allelic status and impulsivity. Those with CC allelic status showed an increase in reward responsiveness only in the stress induction condition. Together, results from the two studies inform the development of a multidimensional model of impulsivity that captures gene-environment influences on discrete aspects of impulsive personality and behaviour. Further refinement of this model may lead to the development of more effective customised prevention and treatment interventions for clinically disordered impulsivity. The implications of dopaminergic systems and stress in understanding disorders such as ADHD and substance dependence are discussed.