Previous research has shown that individuals endorsing inattention and hyperactivity-impulsivity have deficient performance on tasks tapping different aspects of attention. Although there is empirical evidence suggesting that the behavioral domains of inattention and hyperactivity-impulsivity are linked to functioning of independent and separate brain areas and neurotransmitter systems, cognitive characterization of adults presenting with problems within these domains is not complete. The aim for this study was to identify the cognitive correlates of the core behavioral domains that define the diagnosis of AD/HD (i.e., inattention and hyperactivity-impulsivity) in a sample of college students, utilizing a computerized attention task, the Attention Network Test (ANT). Different ANT task components have been found to activate separate brain areas linked to the functioning of alerting, orienting and executive attention, and have the potential to provide an indication of the efficiency of these brain networks. In addition to completing the ANT, the participants filled out questionnaires covering common symptoms of adult AD/HD, anxiety and depression. Hierarchical regression analyses revealed that there were no reliable relationships between self-reported symptoms of current inattention and hyperactivity-impulsivity and ANT performance. Further, self-reported depression and/or anxiety did not seem to impact the efficiency of attention networks to a significant degree in this study sample. Gender proved to be the most consistent predictor of ANT performance. Female gender was related to poorer executive attention efficiency. An exploratory ANCOVA revealed that individuals reporting high levels of impulsivity and emotional lability had poorer executive attention efficiency in comparison to those reporting these behaviors and problems to a lesser extent. Future research is needed in order to further explore the relationship between ANT performance and behavioral expressions of adult AD/HD and other neurological and psychiatric conditions.

The purpose of the study is to examine different situations and behaviors for students diagnosed with AD / HD and see if there are times where their diagnosis will be extra visible. This will ultimately see how and where these children may need support in their daily lives, and about the support they receive is relevant to their needs. Questions I intend to examine: Are there situations for students throughout the school day in which ADHD diagnosis becomes extra visible? If so, what situations? How is the diagnosis in these situations? It is estimated that about 3-6 percent of school children have AD/HD. It causes difficulties with concentration as well as impulse and activity control. It's not a given that these students get the right support. This is a qualitative study using observations of two children to investigate whether there are situations where students' AD/HD will be extra visible. The results show that there are times when these behaviors clearly manifests during the school day, but also that there are some occasions when some behavior is not particularly noticeable. Some behaviors became evident during the free time during the day, while others became more visible during the controlled period. The result also shows that the times when behaviors are apparent, differs between the two observed the students. This emphasizes the importance to look to the specific needs of support for each individual.

Numerous cognitive, personality and situational factors have been found to be related to aggression. Understanding how these factors interrelate is essential to predicting violence and critical to the assessment and treatment of offenders with violent histories. Previous research has suggested a potential role for social problem solving as a mediator between impulsivity and aggression (McMurran et al., 2002). Additionally, it is well established that aggression is more likely to occur in the context of alcohol use (Collins, 1993; Reiss & Roth, 1993; Lipsey, Wilson, Cohen & Derzon 1997). Based on existing literature, a model of aggression was developed involving impulsivity, social problem solving and alcohol dependency. Utilizing path analysis with multiple regression, a mediational model of aggression was assessed on a sample of 179 provincially incarcerated offenders, 87% of whom were Aboriginal and 45% of whom had a previous conviction of domestic abuse. The data suggest that social problem solving, alcohol dependency and impulsivity are all important in understanding and predicting aggression. Social problem solving does not appear to act as a mediator in the relationship between impulsivity and aggression, although preliminary results suggest that impulsivity, may serve the function in this relationship and in the manifestation of aggression. The implications of these findings for our understanding about human factors contributing to aggression and for further advancement of treatment programs are provided.

Using natural supplementation as a treatment tool for mental health problems is becoming increasingly popular. Several studies using a multinutrient supplement called EMPowerplus (EMP+) have been conducted in humans with disorders such as Attention-Deficit/Hyperactivity Disorder (ADHD), but no studies have been conducted in animals or humans without disorders. Therefore, to address the gaps in the literature, the aim of this study was to assess the effects of EMP+ in a rat population on anxiety, aggression, and impulsivity which may be present in people who do not have a disorder. To investigate this, 40 male and 40 female rats were fed a diet consisting of 0%, 1.25%, 2.5% or 5% EMP+. They were tested during adolescence (PND 52-53) and again during mid-adulthood (PND 116-117) for anxiety and aggression, and during early adulthood (PND 92-96) and again during late adulthood (PND 127-130) for impulsivity. Due to the impact of the September 4th 2010 7.1 magnitude earthquake, data for some rats had to be excluded from anxiety and aggression analyses, leaving a sample size of 29 males and 34 females. Although there were no treatment main effects for any of the three behaviours, there were significant interaction effects between treatment and sex for measures of anxiety and aggression, showing that each sex reacted differently to the supplement. Male rats became less anxious, while female rats became more anxious. Of the five aggressive behaviours observed, significant interactions were found between treatment and sex for rough paw and allogrooming frequency. There were no significant effects involving treatment for impulsivity, but male rats were more impulsive when they were older (PND 127-130). Overall, the effects of EMP+ on the rats’ anxious, aggressive, and impulsive behaviours were mixed, and it is likely that the 7.1 magnitude earthquake and its subsequent aftershocks played a role in these results.

Emotional and external eating are common eating behaviours in the general population, while not disordered eating per se they have been linked to overeating, obesity and problems engaging in health behaviours. Theories of emotional and external eating have been around for decades however little is known of the factors that contribute to these eating behaviours. Emotional and external eating tend to co-occur, and high correlations between them have been reported. Some theorists have argued that they are not distinct constructs. The current study aimed to provide further understanding on the nature and distinction between emotional and external eating in a non-clinical sample. The associations of impulsivity, alexithymia and negative affect in emotional and external eating were investigated, utilising a cross-sectional design. These variables have been shown to be related to eating behaviour in clinical samples however there has been limited research in non-clinical samples. Emotional eating was positively associated with alexithymia, negative affect and lack of perseverance, the relationship with urgency was less clear. External eating was indirectly associated with depression through the mediating variable urgency. The results indicated that emotional and external eating do show some similarities in the variables associated with them, however, the pattern of associations were different for the two eating behaviours. It appears from this study that the theoretical distinction between emotional eating and external eating is warranted with emotional eating appearing to be directly associated with problems with affect regulation whereas external eating is indirectly associated with negative affect.

Heterogeneity in children with Attention Deficit Hyperactivity Disorder (ADHD) symptoms is a well-known phenomenon. Empirically, this heterogeneity is evident in at least three different respects: expression of the two ADHD symptom domains (hyperactivity/impulsivity and inattention), neuropsychological impairments, and comorbid behavior problems. The major aim of the present thesis was to examine the heterogeneity characterizing children with ADHD symptoms to enhance our understanding by examining neuropsychological factors with regard to common and independent contributions, and specificity of the two ADHD symptom domains in relation to neuropsychological factors and comorbid behavioral problems. Particular emphasis is placed on prominent neuropsychological processes such as executive functions, state regulation and delay aversion. The present thesis is based on findings from four studies on community-based samples of children – studies involving concurrent and longitudinal designs as well as both categorical and dimensional approaches. Results provide support for the notion that executive function and state regulation, but not delay aversion, constitute independent pathways to ADHD, primarily to symptoms of inattention. However, delay aversion was shown to have an effect in combination with state regulation on both hyperactivity/impulsivity and inattention. Additionally, symptoms of hyperactivity/impulsivity and inattention have different primary correlates concerning neuropsychological factors and comorbidity. More specifically, executive function, state regulation, internalizing problems and academic achievement were specifically related to inattention but not to hyperactivity/impulsivity. Oppositional Defiant Disorder (ODD) was specifically related to hyperactivity/impulsivity, but not to inattention. The present thesis has contributed with important and new knowledge about the heterogeneity of children with ADHD symptoms concerning neuropsychological pathways, and specificity of the two ADHD symptom domains in relation to neuropsychological factors and comorbid behavioral problems. Knowledge such as this can help us understand how to identify more homogeneous ADHD subgroups, and contribute to the further development of multiple pathway models within this area of research.

The current study examined divergences among impulsivity and sensation seeking items from the Zuckerman-Kuhlman Personality Questionnaire Impulsive Sensation Seeking scale in terms of their relations to other personality models, deviance, and laboratory task outcomes. A sample of 654 undergraduates was gathered across two studies and given a Five Factor Model of personality measure (e.g. NEO Five Factor Inventory, NEO Five Factor Report Form), deviance measures (e.g. Antisocial Behavior Inventory, Explicit Attitudes Towards Marijuana Questionnaire), and three laboratory tasks (e.g. Balloon Analogue Risk Task, Newmans Card-Playing Task). Results demonstrated the hypothesized divergences among impulsivity and sensation seeking items on measures of personality and deviance as well as laboratory tasks. We conclude that Impulsive Sensation Seeking is multidimensional and would be more useful if employed as two independent constructs: (Lack of) Premeditation and Sensation Seeking.

Impaired inhibition is a deficit of several psychopathological disorders, particularly attention-deficit hyperactivity disorder (ADHD). In the first study, a meta-analysis was conducted to determine whether impaired inhibition as measured by the Stop Signal Task is specific to ADHD, or whether it could be found in other psychopathological disorders. The meta-analysis found an inhibitory deficit in ADHD, but also in obsessive compulsive disorder (OCD) and schizophrenia (SCZ), suggesting that deficient inhibition is not specific to ADHD. A common neural mechanism may underlie deficient inhibition in ADHD, OCD, and SCZ. Study 2 aimed to determine the neural basis of inhibition using a lesion-deficit approach in children with traumatic brain injury (TBI). Only TBI children with white matter lesions in the superior frontal gyrus (SFG) region showed impaired inhibition compared with orthopedic injury controls. This suggests that deficient inhibition may stem from frontal lobe white matter damage, particularly in the SFG.

Impaired inhibition is a deficit of several psychopathological disorders, particularly attention-deficit hyperactivity disorder (ADHD). In the first study, a meta-analysis was conducted to determine whether impaired inhibition as measured by the Stop Signal Task is specific to ADHD, or whether it could be found in other psychopathological disorders. The meta-analysis found an inhibitory deficit in ADHD, but also in obsessive compulsive disorder (OCD) and schizophrenia (SCZ), suggesting that deficient inhibition is not specific to ADHD. A common neural mechanism may underlie deficient inhibition in ADHD, OCD, and SCZ. Study 2 aimed to determine the neural basis of inhibition using a lesion-deficit approach in children with traumatic brain injury (TBI). Only TBI children with white matter lesions in the superior frontal gyrus (SFG) region showed impaired inhibition compared with orthopedic injury controls. This suggests that deficient inhibition may stem from frontal lobe white matter damage, particularly in the SFG.

abstract: Research in the area of childhood trauma has shown a substantial amount of psychological maladjustment following the experience of traumatic events in childhood. Trauma survivors are at risk for developing a multitude of adverse psychological outcomes as well as unsafe behaviors following the event of trauma. One unifying theme within these psychological sequelae is the nature of impulsive behaviors. Delay-discounting refers to the subjective decrease in value of a reward when its presentation is delayed. Delay-discounting is often used as an index of impulsive behavior. This study poses two primary questions: 1) Can childhood trauma predict rates of delay-discounting? 2) Could delay-discounting predict psychological maladjustment for individuals who have experienced childhood trauma? This study will seek to answer these questions using an online version of the Kirby et al., 1999 hypothetical delay-discounting method, as well as the Barratt Impulsiveness Scale (BIS-11), to measure trait impulsivity. Measures of depression (BDI-II), life events (LEC), post-traumatic stress (PCL-C), and drug and alcohol abuse (DAST-20) will also be included. Participants included a sample of university students ages 18-52 (n=521, females = 386, males = 135) with a mean age of 25.19 years. Results indicated that childhood trauma was not a significant predictor of delay-discounting rate, nor was delay-discounting rate a significant predictor of psychological maladjustment. Limitations and future directions are discussed. / Dissertation/Thesis / M.S. Psychology 2012