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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.

Working memory refers to the ability to retain information for short periods of time to guide future behavior. This type of short-term memory has been shown to play an important role in mental disorders such as schizophrenia and therefore further investigations into the neural basis of this cognitive function may aid in the study of disease states where this cognitive function is defective. A likely neural correlate of working memory has been identified in the persistent neural activity observed during the memory retention intervals of various behavioral tasks. Computational and cellular physiology has suggested that this persistent activity depends on NMDA receptor activation. Indeed, pharmacological studies on both human and animal subjects have reported a significant decrease in working memory task performance following the administration of NMDA-antagonists such as ketamine. However, the task and experimental design of these previous studies have not been ideal, and have therefore only shown equivocal evidence that NMDA-antagonists impair working memory, especially its capacity. Here we aimed to determine the effect of low-dose ketamine injection (0.25-mg/kg and 0.50-mg/kg IM) on the performance of macaque monkeys on a visual sequential comparison task, a task whose performance has minimal influence from other cognitive functions besides working memory. All monkeys showed a detrimental effect of ketamine administration on visual working memory performance, either at higher ketamine doses or with high memory loads. There was also an effect on performance in sessions without a memory component, indicating that the effect of ketamine was no limited to working memory maintenance. Although the effect of ketamine on memory load varied per animal, this study provides solid evidence in support of the hypothesis that working memory maintenance is dependent on NMDA receptor integrity. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2011-05-27 14:56:41.726

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

This thesis charts the shifts in metaphors of memory associated with the digitization of personal photography – from ‘archiving’ to ‘sharing’ – developing a strong account of the role of metaphor in shaping cultural conceptions and material technologies of memory making in relation to photography. Early discourse surrounding the emergence of photography heralded the camera as a medium capable of capturing the imprinted trace (light) of the real. By extension, photography has routinely been figured as an essential means through which ‘the social’ can be captured, framed, communicated, and distributed, with personal photographs historically positioned as visual ‘archives’ of the self. Underlying this are specific metaphorical conceptions of the relationships between human memory, reality and representation. This thesis considers how metaphors of the ‘memory-archive’ have naturalized historically specific ideas about human memory which have in turn come to serve as models for the design and ongoing use of photographic technologies. This thesis argues for a sociology of metaphor, which can account for the ideological potential of metaphor in constructing a specific paradigm of memory, while advancing the material consequences of metaphor as a constitutive agent that enables and constrains the possibilities for memory making. The thesis focuses upon the metaphoric shifts from analogue preservation or ‘archiving’ to online distribution or ‘sharing’ within digital landscapes. The central chapters of the thesis consider the ways in which particular metaphors of memory – as archive, as distributed, as shared – are materialized as technologies, in this case photographic media. By exploring three key technologies – the Kodak EasyShare Camera, Cloud Computing, and the Instagram Application – the thesis examines the ways in which new metaphors of memory and of the social are becoming materially embedded. The thesis further reveals residual anthropocentric ideas of memory and technology, which continue through metaphors of photo-sharing which further disguises the role of the ‘technological unconscious’ in shaping potential memories. / Thesis (Master, Sociology) -- Queen's University, 2011-10-03 11:45:10.155

Working memory is the ability to store relevant information temporarily to guide future thought and behavior. It is a basic cognitive function instrumental to processes such as learning, reasoning, comprehension and mental arithmetic. Central to mental disorders, such as attention deficit hyperactivity disorder (ADHD), are impairments in cognition including working memory. It is essential to understand working memory, if we want to understand human cognition and mental disorders. A neural correlate of working memory has been identified as selective persistent activity during the retention intervals of tasks that probe working memory. The signal-to-noise ratio of persistent activity can be modulated by catecholamines, neuromodulators that are depleted in many mental disorders, including ADHD. Such modulations should be evident at the level of behavior, particularly as the demands imposed on working memory are increased. To test the contribution of catecholamines to working memory, we opted to administer methylphenidate to three female macaque monkeys. Methylphenidate is a dopamine and norepinephrine reuptake inhibitor that effectively increases their availability in the brain. By having monkeys perform a visual sequential comparison task, which allows the systematic manipulation of working memory load, we tested the hypothesis that increased catecholamine levels modulate task performance in a dose- and memory load-dependent way. Systematic administration of a wide range of doses of methylphenidate (0.1 – 9 mg/kg) did not affect performance on the visual sequential comparison task in either a dose- or memory load-dependent manner. Given these results, we further tested the effects of methylphenidate on overt attention in a visual search task. Again, we did not observe a dose-dependent effect on performance. Nevertheless, methylphenidate was found to generally increase the monkeys’ motivation. We suggest that the positive effect on motivation, elicited by an increased level of catecholamines, might have led to changes in performance observed in previous literature, but not to changes in the ability of retaining visual information per se. These findings question the previously suggested influence that catecholamines exert on cognition, and suggest that the role of catecholamines in working memory should be reevaluated. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2012-05-30 14:04:54.891