One major focus of anxiety research in recent years has been the identification of cognitive factors that promote increased vulnerability to anxiety. Cognitive formulations propose that anxiety is characterised by an increased tendency to attend to negatively valenced emotional information, and that this bias may play a causal role in the development and maintenance of clinical anxiety. Evidence suggests that this anxiety-linked processing bias occurs even in conditions in which the stimuli are masked in order to prevent awareness of the content (i.e., preattentive bias). The present thesis focused principally on the preferential processing of threat-related information that occurs outside awareness. Two different outcome measures were used to index preferential preattentive processing of threat-related information in non-clinical populations: The emotional Stroop task was used to index selective attention to masked presentation of threatening word stimuli, whereas skin conductance responses were used to index selective autonomic responses to masked presentation of threatening pictorial stimuli. The empirical studies in the present thesis showed that elevated levels of trait anxiety promote preferential preattentive processing of negatively valenced information, whereas elevated levels of social desirability (interpreted as defensiveness) generally prevent preferential preattentive processing of negatively valenced information, especially among those at higher levels of trait anxiety, irrespective of outcome measure used. Moreover, previous research has demonstrated that a person’s most common emotional reaction when encountering a stressful event is causally influenced by that person’s habitual tendency to selectively encode the most threatening aspects of all available information. Thus, preattentive bias (as measured with the emotional Stroop task) was used to predict the emotional responses (as seen on self-reported emotional distress and autonomic reactivity) following exposure to a laboratory stressor. This study showed that preattentive bias to negative information had significant effects on both self-reported and physiological measures in response to a laboratory stressor, but in diametrically opposite directions. Specifically, whereas preattentive bias was positively associated with self-reported negative emotional response, it was negatively associated with a physiological indicator of emotional response. The results were discussed in terms of an inability to automatically inhibit the processing of threatening cues, which seems to be a vulnerability marker for anxiety. Whether this bias is ultimately sufficient for the development of clinical anxiety remains to be examined in future research. Additionally, more information is needed before it can be established that the emotional Stroop task can be viewed as a reliable diagnostic tool for determining an individual’s anxiety status.

The present study examined the relation between self-report mindfulness and performance on tasks measuring abilities for three aspects of attention: sustained, selective, and attention switching. Because attention regulation has been described as a core component of mindfulness, and past research suggests that experience with mindfulness meditation is associated with improved attentional skills, the present study predicted that higher self-report mindfulness would be positively related to performance on tasks of attention. Fifty undergraduate students completed self-report mindfulness questionnaires and completed a battery of attention tasks. There was mixed support for the relation between mindfulness scores and sustained attention, such that higher mindfulness scores as measured by the MAAS and CAMS-R were negatively related to target omissions on the CPT-II, but were not related to RT variability on the CPT-II or PASAT performance. Findings are discussed in the context of the measurement of self-report mindfulness, and directions for future research are considered.

Human vision is remarkable. By limiting the main concentration of high-acuity photoreceptors to the eye's central fovea region, we efficiently view the world by redirecting the fovea between points of interest using eye movements called <em>saccades</em>. <br /><br /> Part I describes a saccadic vision system prototype design. The dual-resolution saccadic camera detects objects of interest in a scene by processing low-resolution image information; it then revisits salient regions in high-resolution. The end product is a dual-resolution image in which background information is displayed in low-resolution, and salient areas are captured in high-acuity. This lends to a resource-efficient active vision system. <br /><br />Part II describes CMOS image sensor designs for active vision. Specifically, this discussion focuses on methods to determine regions of interest and achieve high dynamic range on the sensor.

This thesis concerns selective attention in the context of the Stroop task (identify the colour) and Reverse Stroop task (identify the word). When a person is asked to select and identify one dimension of a bidimensional stimulus (e. g. , the word RED printed in green) the typical finding is that the word influences colour identification (i. e. , the Stroop effect) but the colour does not influence word identification (i. e. , no Reverse Stroop effect). A major account of performance in these tasks posits that one dimension interferes with the other only when a translation occurs (e. g. , Roelofs, <i>Psychological Review, 2003</i>; Sugg & McDonald, <i>Journal of Experimental Psychology: Human Perception & Performance, 1994</i>; Virzi & Egeth, <i>Memory & Cognition, 1985</i>). This translation assumption is implicit in virtually all work in the field. The first part of this thesis completely undermines the translation assumption. In a series of four experiments (two unique paradigms), I demonstrate that interference from the colour in a Reverse Stroop task occurs in the absence of a translation. The second part of this thesis contains two additional experiments designed to discriminate between translation effects and response conflict effects. The results of these experiments confirm that a translation was not required because no stimulus conflict effect, the most likely locus of a translation effect, was observed. However, response conflict effects were observed. The third part of this thesis implements a computational model based on the principle that the strength of association (Cohen, Dunbar, & McClelland, <i>Psychological Review, 1990</i>) between a specific stimulus and its response (Logan, </i>Psychological Review, 1988</i>) is important in determining the influence of the irrelevant dimension. This model has no translation mechanism. A final experiment was conducted to test this model; the model accounted for over 98% of the variance in RTs and 92% of the variance in interference and facilitation scores in both the Stroop and Reverse Stroop tasks independent of whether a translation was required.

Decrements in selective attention are a commonly experienced phenomenon that has practical implications for many industries. Two causes of such deficits are mental fatigue and alcohol intoxication, which impair selective attention by decreasing the efficiency of inhibitory processes. The present research examined the effects of these two factors on the selective attention subtest of the Useful Field of View test in both a baseline and an experimental session. Participants in the mental fatigue condition (n = 14) were tested while performing a divided attention task for two hours to induce mental fatigue. Those in the alcohol condition (n = 10) were tested while achieving a peak blood alcohol content of 0.05%. No differences between the two groups were observed, nor was a significant decline in selective attention observed as a result of either manipulation. The results indicate three possible explanations for this lack of a difference including a floor effect on the selective attention task, a pop-out effect in switching from the divided to the selective attention task, and an increase in attentional effort regulation due to the contrast in difficulty of the divided and selective attention tasks.

Children with Fetal Alcohol Spectrum Disorder (FASD) may suffer numerous cognitive impairments, including significant problems with executive functioning, language, attention, and memory [40]. It is estimated that two to five percent of children born in the U.S. are affected by FASD [34]. It has been shown that training improvements can be made in working memory and attention in children with ADHD [25]. Computerized training with game elements enhances not only motivation but training efficacy of these interventions [38]. This thesis examines the creation of two suites of serious games, Cognitive Carnival and Caribbean Quest, intended to improve working memory aspects of attention with the assistance of a trained psychology interventionist in a therapeutic setting. A game-based approach is chosen to provide motivation to children for sustained cognitive challenges presented by cognitive exercises built into the gameplay. Cognitive Carnival was shown by interventionists to have positive effects in neuropsychological studies of populations of children with epilepsy and FASD [33, 30]. / Graduate

Individuals attend to a variety of various stimuli on a daily basis and their brains decide what to attend to and what to tune out. How the brain chooses what is most important to pay attention to is decided with threat level, novelty, emotion, and other criteria. The current study looked at responses from 41 participants who identified high or low with University of Kentucky, Western Kentucky University, and/or Christianity. The participants where shown two images, the UK logo and either the WKU logo, an out-ofstate team logo, or a Christian symbol. Directly after the two images were presented, a dot appeared on the screen and the participants tapped a key on the keyboard to indicate on which side of the screen the dot was placed. The hypothesis stated that participants’ mean reaction time for identifying the side of the screen the dot was on when under a logo or a symbol with which the participants highly identify would be faster than the mean reaction time to a dot under logos or symbols with which the participant had low identification. However, results of this study did not show statistically significant differences in the mean reaction times of the participants.

Most events that we encounter in everyday life provide our different senses with correlated information, and audiovisual speech perception is a familiar instance of multisensory integration. Several approaches will be used to further examine the role of cognitive factors on audiovisual speech perception. The main focuses of this thesis will be to examine the influences of cognitive load and selective attention on audiovisual speech perception, as well as the integration of auditory and visual information in talking distractor faces. The influence of cognitive factors on the temporal integration of auditory and visual speech, and gaze behaviour during audiovisual speech will also be addressed. The overall results of the experiments presented here suggest that the integration of auditory and visual speech information is quite robust to various attempts to modulate the integration. Adding a cognitive load task shows minimal disruption of the integration of auditory and visual speech information. Changing attentional instructions to get subjects to selectively attend to either the auditory or visual speech information also has a rather modest influence on the observed integration of auditory and visual speech information. Generally, the integration of temporally offset auditory and visual information seems rather insensitive to cognitive load or selective attentional manipulations. The processing of visual information from distractor faces seems to be limited. The language of the visually articulating distractors doesn't appear to provide information that is helpful for matching together the auditory and visual speech streams. Audiovisual speech distractors are not really any more distracting than auditory distractor speech paired with a still image, suggesting a limited processing or integration of the visual and auditory distractor information. The gaze behaviour during audiovisual speech perception appears to be relatively unaffected by an increase in cognitive load, but is somewhat influenced by attentional instructions to selectively attend to the auditory and visual information. Additionally, both the congruency of the consonant, and the temporal offset of the auditory and visual stimuli have small but rather robust influences on gaze. / Thesis (Ph.D, Psychology) -- Queen's University, 2011-09-30 23:31:07.754

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Living environments are seldom, if ever, devoid of all background auditory stimuli. However, the relationship between particular structural components of acoustic backgrounds and cognitive task performance remains unclear. Two experiments were completed to examine the influence of sound on a visual selective attention task. Participants performed the Stroop task (Stroop, 1935) while silence or background acoustic patterns of various complexities were presented over headphones. No effect of background sound on performance was found. A post-hoc analysis indicated that in comparison with participants who do not regularly listen to music while studying, participants who regularly listen to music while studying performed better on the Stroop task when a structured auditory pattern that included variation in both frequency and time interval was presented in the background. These results indicate that distinct structural components of background auditory sequences may interact with individual characteristics to influence cognitive performance on a task involving selective attention.