The locus coeruleus (LC) is a nucleus within the brainstem associated with physiological arousal and attention performance, with altered structure and function previously identified in neurodegenerative disorders. Pathologies related to difficulties with attention have previously been understood within a cortical triple network model, abnormalities in which may be relate to dysfunction in either LC structure or function. To examine the possibility of LC alteration being associated with inattentive symptom report, a set of analyses have been performed. In the first analysis, LC neuromelanin contrast was regressed onto ADHD symptom report for 141 individuals across the lifespan, finding a significant negative relationship between neuromelanin in the right hemisphere of the LC and inattentive symptom report. A second analysis tested for possible mediation of the neuromelanin contrasts with structural volumes of regions associated with the salience network, which has also been previously associated with attention deficits and ADHD symptoms. These findings support the relationship between LC and attention-related behavior through both neuromelanin-sensitive and structural imaging, and observes multiple significant structural associations for cortical regions previously associated to inattention functionally. / Master of Science / Within the brainstem is a collection of neurons called the Locus Coeruleus (LC), associated with the production of neurotransmitters associated with attention. In Magnetic Resonance Imaging (MRI) networks of brain regions associated with attention have been previously observed, with both differences in region connections and abnormalities in region composition being observed. Given the small size of the LC general volume measurement is considered difficult, but use of multi-atlas techniques and neuromelanin contrasts allow for methods of LC structure and integrity to be compared. The present study attempts to integrate the LC into this larger concept of attention processing, called the triple network model, by testing associations between structural measures of the LC, regions associated with the three triple network model networks, and attention report in 140 participants. LC contrasts were found to be significantly associated with inattention, as were structural values for the regions connected to the previously identified networks. Mediation of neuromelanin by these regions failed to produce significant results, but neuromelanin was mediated by the volume of the LC itself. The findings here support continued use of these structural techniques with regard to the LC and other applicable neural structures, as well as further work to define the relationship between the LC and the triple network model.

L’objectif de ce mémoire est de mieux comprendre un des biais cognitifs susceptibles d’affecter le pouvoir prédictif des sondages : le biais de négligence de la corrélation. Intuitivement, le biais de négligence de la corrélation est une simplification du processus de décision chez les votants qui les amène à ignorer la corrélation entre leurs préférences électorales et les coûts de participation au vote. Afin d’analyser ce biais, nous avons conduit une expérience consistant en une série de questions-réponses sous la forme de sondages. Les participants se réfèrent à un ensemble d’informations sur les gains et les coûts rattachés à leurs choix de vote. Les résultats expérimentaux montrent que le biais de négligence envers la corrélation affecte significativement les réponses des participants aux questions de sondage. De plus, certaines caractéristiques socioéconomiques des participants semblent augmenter la probabilité de souffrir du biais. Enfin, l’analyse des données recueillies lors de l’expérience montre que la mesure proposée du biais n’était pas calculable pour certaines observations car les participants avaient effectué des choix certains.

<p>Previous research has shown both positive and negative effects of gaming on academic and cognitive performance. The purpose of this study was to assess the effect of gaming on development of working memory (WM), inattention, reading and math ability using a longitudinal design. A randomly chosen sample of 335 (168 girls) 6–25 year olds performed tests of visuo-spatial and verbal WM, reading and math ability twice, with a two year interval. Gaming and inattention were assed with questionnaires. Time spent gaming did not affect development of any of the variables. However, game category did correlate with development of visuo-spatial WM, with action-gamers having a more favourable development. There was, however, no positive interaction with more time spent gaming for action-gamers. These results suggest that gaming should not be regarded as a damaging leisure activity. There could instead be some positive effects of gaming, but future research should try to identify the aspects of gaming contributing to this effect.</p>

<p>Gaming has become one of the most common activities for children and adolescents, and it is therefore of interest to investigate effects of gaming on cognition and behavior. The present study investigates if gaming is related to working memory capacity (WMC) or inattentive symptoms. We distinguished between three categories: action games, strategy games and non-gamers. The present study hypothesized that games involving higher cognitive functions, such as strategy games, could have an enhancing effect on working memory. A total of 211 children (age 5-16) participated. Gaming and inattentive behaviour was measured through parental assessment. WMC was measured with one verbal and one visuospatial task. No relation between gaming and inattentional symptoms was found. Strategy gamers performed better on the visuospatial and the verbal WM-tasks, but more time spent playing strategy games was not associated with significantly higher WMC, which indicates that this finding could be due to self-selection rather than being an causal effect of playing.</p>

<p>Gaming has become one of the most common activities for children and adolescents, and it is therefore of interest to investigate effects of gaming on cognition and behavior. The present study investigates if gaming is related to working memory capacity (WMC) or inattentive symptoms. We distinguished between three categories: action games, strategy games and non-gamers. The present study hypothesized that games involving higher cognitive functions, such as strategy games, could have an enhancing effect on working memory. A total of 211 children (age 5-16) participated. Gaming and inattentive behaviour was measured through parental assessment. WMC was measured with one verbal and one visuospatial task. No relation between gaming and inattentional symptoms was found. Strategy gamers performed better on the visuospatial and the verbal WM-tasks, but more time spent playing strategy games was not associated with significantly higher WMC, which indicates that this finding could be due to self-selection rather than being an causal effect of playing.</p>

Previous research has shown both positive and negative effects of gaming on academic and cognitive performance. The purpose of this study was to assess the effect of gaming on development of working memory (WM), inattention, reading and math ability using a longitudinal design. A randomly chosen sample of 335 (168 girls) 6–25 year olds performed tests of visuo-spatial and verbal WM, reading and math ability twice, with a two year interval. Gaming and inattention were assed with questionnaires. Time spent gaming did not affect development of any of the variables. However, game category did correlate with development of visuo-spatial WM, with action-gamers having a more favourable development. There was, however, no positive interaction with more time spent gaming for action-gamers. These results suggest that gaming should not be regarded as a damaging leisure activity. There could instead be some positive effects of gaming, but future research should try to identify the aspects of gaming contributing to this effect.

Gaming has become one of the most common activities for children and adolescents, and it is therefore of interest to investigate effects of gaming on cognition and behavior. The present study investigates if gaming is related to working memory capacity (WMC) or inattentive symptoms. We distinguished between three categories: action games, strategy games and non-gamers. The present study hypothesized that games involving higher cognitive functions, such as strategy games, could have an enhancing effect on working memory. A total of 211 children (age 5-16) participated. Gaming and inattentive behaviour was measured through parental assessment. WMC was measured with one verbal and one visuospatial task. No relation between gaming and inattentional symptoms was found. Strategy gamers performed better on the visuospatial and the verbal WM-tasks, but more time spent playing strategy games was not associated with significantly higher WMC, which indicates that this finding could be due to self-selection rather than being an causal effect of playing.

In an era where the diagnosis of attention deficit/hyperactivity disorder (ADHD) is as high as 7% in school-aged children, the search for causes and preventions has never been more important. Current research indicates a positive relationship between bilingualism, particularly native bilingualism, and executive function in normally developing individuals. This study served to examine the potential relationship between bilingual education in a public school setting and the presence of ADHD symptoms in that school's students. This was a comparative analysis of students in a South Florida School District's two-way immersion program with the national average in terms of frequency of ADHD symptoms using the NICHQ Vanderbilt Assessment Scale and the Swanson, Nolan, and Pelham (SNAP). The results did not show any significant differences between groups in terms of language history, gender, race, or family structure.

Massie, Blower, and Campbell (1997) indicate that trucks that operate less than 50 miles from the vehicle's home base comprise 58% of the trucking industry. However, despite being the largest segment, research involving local/short haul (L/SH) operations has been scant. In fact, little is known about the general safety issues in L/SH operations. As a precursor to the present research, Hanowski, Wierwille, Gellatly, Early, and Dingus (1998) conducted a series of focus groups in which L/SH drivers provided their perspective on safety issues, including fatigue, in their industry. As a follow-up to the Hanowski et al. work, the effort presented here consisted of an on-road field study where L/SH trucks were instrumented with data collection equipment. Two L/SH trucking companies and 42 L/SH drivers participated in this research. To the author's knowledge, this is the first in-situ data collection effort of its kind with L/SH drivers. The analyses focused on determining if fatigue is an issue in L/SH operations. Of primary interest were critical incidents (near-crashes) where drivers were judged to be at fault. The results of the analyses indicated that fatigue was present immediately prior to driver involvement in at-fault critical incidents. Though it is difficult to determine why fatigue was present, the results seem to indicate that much of the fatigue that the drivers' experienced was brought with them to the job, rather than being caused by the job. There are four basic outputs of the Phase II research: (1) a description of the L/SH drivers who participated, (2) a description of critical incidents, (3) a determination if fatigue is an issue in L/SH trucking, and (4) the validation of the fatigue factors cited in Hanowski et al. (1998) using a proposed fatigue model. These four outputs culminate in a set of pragmatic guidelines to address fatigue and other safety issues in L/SH operations. Five guidelines are proposed that are directed at: (1) driver education with regard to on-the-job drowsiness/inattention, (2) driver education with regard to sleep hygiene, (3) driver training, particularly for novice L/SH truck drivers, (4) driver screening, and (5) public monitoring of L/SH driver performance. / Ph. D.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.