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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

MEMORY AND ATTENTIONAL BIASES ASSOCIATED WITH PERFECTIONISM: THE IMPACT OF MOOD AND THREAT RESPONSIVENESS

Desnoyers, Amanda 07 November 2013 (has links)
Research has argued that perfectionism, as well mood state, can serve to influence the type and amount of information that will be attended to and remembered in one’s surrounding environment. The purpose of the current study was to look at how mood and differing degrees of threat may influence the cognitive processes of individuals higher in perfectionism. Following completion of the perfectionism measures, 121 post-secondary students were exposed to a mood induction as well as a threat condition and then asked to complete three cognitive tasks – d2 test of attention, emotional Stroop, and a recognition task. Results indicated that perfectionism was associated with accuracy and reaction time and this impact differed based on mood and threat. Results also indicated individuals higher in perfectionism had a memory bias towards negative and perfectionistic content, reinforcing the idea that perfectionism has a distinctly cognitive component that impacts how an individual processes incoming information.
152

Cognitive Training With Video Games: The Role of Target Presentation Rate and Maximum Target Eccentricity

Mouck, Andrew 25 September 2010 (has links)
Action video games have been shown to improve the visual cognitive abilities of those who played them for as little as ten hours when compared to those who played a control non-action video game for the same period (Green & Bavelier, 2003). The purpose of the current study was to examine which specific traits of action video games are responsible for which specific changes in visual cognition occurring while playing action video games. To test this, the visual cognitive abilities of participants were measured using a battery of five tasks before and after ten hours of practice with one of four versions of a simplified action video game. The battery was chosen to measure different aspects of the visual cognitive system. The Useful Field of View task measures the amount of visual angle the participant can actively attend to at any given time, the spatial limit of visual attention. The Attentional Blink task measures the ability to monitor one location over time, the temporal flexibility of visual attention. The Flanker task measures interference of a task-irrelevant object on a primary task, and is thought to provide an indirect measure of attentional capacity. The Visual Reaction Time task was intended to be a measure of visual apprehension speed and response generation. The Visual Search task was intended to measure the ability to find and identify a target amongst distractors. Participants were randomly assigned to one of four training conditions in a 2X2 factorial design manipulating the rate at which targets appeared and the maximum eccentricity at which the targets appeared during training. The paradigm provided evidence that faster target training rates caused a marginal improvement over the slow rates in the Useful Field of View task from pre-training to post-training. Training with the fast target rate caused greater improvement than the slow rate on the Attentional Blink at only lag 2 and and a reversed effect at lag 6. All groups improved from pre-training to post-training on the Useful Field of View, Attentional Blink and Visual Search tasks. However, there was no differential effect for the narrow and wide training eccentricities. / Thesis (Master, Psychology) -- Queen's University, 2010-09-24 11:52:47.173
153

Neural correlates of selective attention in cognitively normal older adults, patients with mild cognitive impairment and patients with mild Alzheimer's disease

YE, BING 28 September 2010 (has links)
It is well established that people experience a decline in cognitive functions, such as selective attention (SA), as they get older. SA is the ability to focus on task-relevant information and suppress task-irrelevant information. The Stroop task has been used to assess SA. In the current study, the neural correlates of SA were investigated using functional MRI-Stroop task with cognitively normal older adults (NC), patients with amnestic Mild Cognitive Impairment (aMCI) and patients with mild Alzheimer’s disease (AD). The current study reanalyzed previous master student’s data, due to the disagreement in analyzing the data. In the fMRI data analysis, the contrast of correct responses in the naming incongruent color (SC) condition minus correct responses in the reading incongruent word (RW) condition (SC-RW) in series 2a and 2b was reanalyzed using an event-related analysis. The current Stroop experiment was in a block design with four series: series 0, series 1, series 2a and 2b. In behavioral analysis, the performance of the word-reading task was expected to be significantly better than the color-naming task in series 1, series 2a and 2b because the belief that reading incongruent color word was always an easier task than the color-naming task. The results from behavioral analysis showed that significant more errors were made in reading incongruent color words in series 2a and 2b than in series 1. In the functional MRI data analysis, although brain activation associated with inhibition was expected in the contrast of SC-RW of series 2a & 2b, the results did not show any brain activation. The unexpected results could be due to the RSE that was elicited by the task switching paradigm of series 2a and 2b. The results suggest that the current Stroop task adapted from the Stroop Neuropsychological Screening Test may not yield a Stroop interference effect of sufficient magnitude to be detected with fMRI in the contrast of SC-RW of series 2a and 2b. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2010-09-24 11:33:28.83
154

The Effects of Feature-Based and Memory-Driven Attention on Appearance

RAJSIC, JASON 30 September 2011 (has links)
Recent evidence suggests that, in addition to improving performance, spatial attention alters the perceptual experience of visual stimuli. We investigated whether two other forms of attention – feature-based attention, and memory-driven attention – also produce an increase in the perceived contrast of stimuli. Perceived contrast was measured by requiring participants to report which of two Gabor stimuli appeared higher in contrast, under different attentional or memory conditions. In Experiment 1, our results indicated that participants indeed allocated attention in a feature-based manner, but no increase in perceived contrast when attending to a given colour was found. Instead, feature-based attention appears to have produced a response bias, such that a stimulus was selected more often when it was attended. In Experiment 2, no change in perceived contrast due to the memory task was observed. A subsequent experiment indicated that our memory task may not have succeeded in causing an attentional shift, which limits the scope of our conclusions on the relationship of memory to perception, but is informative for the development of effective memory manipulations. Overall, our results have provided evidence that the mechanisms of feature-based attention may not be identical to those of spatial attention, but have left the effects of memory-driven attention to be determined. / Thesis (Master, Psychology) -- Queen's University, 2011-09-30 14:25:01.967
155

The Role of Attention and Perception in the Control of Visually Guided and Memory-Guided Actions

Armstrong, Graeme A B Unknown Date
No description available.
156

A developmental study of visual filtering /

Dagenais, Catherine January 1992 (has links)
Visual selective attention was investigated in children aged 5, 7 and 9 and in adults. The groups were compared on a filtering task in which conditions varied with regard to number (0, 2, 8) and location (close, far) of the non-relevant stimuli surrounding the targeted stimuli and the presence or absence of a solid-line border around the target stimuli. The results were analyzed with regard to development differences between the age groups. Contrary to expectations, the presence of non-relevant stimuli was not related to impaired performance nor was the presence of a solid-line border related to enhanced performance. No effect of border was found in any of the groups. However, the reaction times of older children and adults were faster with 8 non-relevant stimuli far from the target. Five year old children did not show this effect. This indicates that older children and adults can utilize this group of non-relevant stimuli as a tool to focus the attentional lens.
157

Cognitive impulsivity in children and the effects of training

Garson, Chrystelle January 1977 (has links)
No description available.
158

Reinforcement and response inhibition in children with attention-deficithyperactivity disorder

Iaboni, Fiorella. January 1996 (has links)
This thesis reports on two studies which examined possible inhibitory deficits in children with attention-deficit/hyperactivity disorder (ADHD), as well as the children's response to reinforcement contingencies. In the first study, a go/no-go discrimination learning task developed by Newman, Widom, and Nathan (1985) was used to investigate the effects of reward and response costs on the ability of ADHD and normal children to learn to respond to some stimuli and inhibit responding to others. Children were tested on four conditions involving different combinations of rewards and response costs. ADHD children showed poorer inhibitory control compared to control children across the four conditions, implicating a generalized inhibitory deficit. Study 2 assessed the psychophysiological responses of ADHD and control children to reward and the termination of reward during a repetitive motor task. Based on Gray's (1982, 1987a, 1987b) psychobiological model, Fowles (1980, 1988) suggested that heart rate increases during reward are reflective of activity in Gray's hypothesized behavioral activation system, while skin conductance increases when reward is removed are reflective of activity in his behavioral inhibition system. Compared to control children, ADHD children failed to show the expected increase in skin conductance during extinction, implicating a deficit in their behavioral inhibition system. In addition, ADHD children showed faster heart rate habituation to reward which, together with other evidence discussed, suggests that they also have behavioral activation abnormalities. This, the findings from the two studies provide strong evidence that ADHD children have both generalized inhibitory deficits and an abnormal response to rewards which, in some situations, may exacerbate their poor inhibition.
159

Orienting of visual attention among persons with autism spectrum disorders : reading versus responding to symbolic cues

Landry, Oriane. January 2006 (has links)
Persons with autism spectrum disorders (ASD) appear to be slower to interpret the meaning of symbolic cues. This could be because they are slower to read the symbolic cue, or because they are slower to select a response to the symbolic cue. Groups of participants with autism (n=11), participants with Asperger syndrome (n=9), and typically developing children (n=16) completed four forced-choice reaction time tasks to examine whether persons with ASD are slower to process the symbolic cue or slower to prepare a response to the cue. The participants completed two control conditions and two orienting conditions using non-predictive central arrow cues. In the Target and Cue conditions, participants gave a speeded response to the appearance of either a target (x) or a central arrow. In the Variable Cue Exposure (VCE) condition, the exposure time to the cue varied (100, 300, 600, or 1000 ms) and was followed by a 100 ms blank screen before the presentation of the target. In the Constant Cue Exposure (CCE) condition, all cues were presented for 100 ms and were followed by blank screens that varied in presentation length (100, 300, 600, or 1000 ms) before the presentation of the target. The results indicated that each group showed a unique pattern of responding. In both the Target and Cue conditions, participants with autism were slower than both Asperger syndrome and typically developing children. In both the VCE and CCE conditions, behavioural effects of the cue were found for participants with autism at longer SOAs than for Asperger syndrome, and at longer SOAs for Asperger syndrome than for typically developing children. These findings support the notion that persons with ASDs are impaired in their preparation of responses as opposed to impaired in reading the meaning of the cue. Further, both the ASD groups showed stronger facilitation effects at longer SOAs than typically developing children, indicating that they were less able to use cue predictability to mediate responding. The differences found between autism and Asperger syndrome are discussed in terms of developmental and clinical distinctions between the groups, and implications for theory and research design.
160

Developmental differences in global and local perception : evidence from divided and selective attention tasks

Kovshoff, Hanna. January 2001 (has links)
The developmental trajectories of selective and divided attention were examined in relation to the processing of hierarchically integrated stimuli. Items consisted of square, diamond, and circle forms made up of smaller squares, diamonds, and circles. Participants included 20 observers in 5 age groups (6, 8, 10, 12, and 24) who decided whether a square or diamond was presented on any given trial. In one set of trials, they were told to selectively attend (and respond) at only one level of analysis (global or local) whereas in the divided attention task, the target could appear at either level. This procedure allowed a unique comparison between selective and divided attention tasks using the same stimuli, task requirements, and instructions. Thus only the mental and attentional state of the observer was manipulated across tasks. In addition, for the divided attention task, observers were biased to one level of analysis. For both tasks and for the cross-task comparison, a clear and qualitative developmental shift was evident from six years of age to eight and ten years of age. The shift occurred in terms of selective attention, sensitivity to the probability of bias, and relative efficiency in processing global and local targets.

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