Publication Date
2016
Document Type
Dissertation
Committee Members
Joseph Houpt (Committee Member), Alan Pinkus (Committee Member), Valerie Shalin (Committee Member), Scott Watamaniuk (Advisor)
Degree Name
Doctor of Philosophy (PhD)
Abstract
The current study simultaneously examined the potentiality of a magnocellular attentional advantage and the competition between top-down and bottom-up processing on attention during visual search as measured by covert and overt visual attention. Specifically, the study tested two opposing views of the competition between top-down and bottom-up processing. The contingent involuntary orienting hypothesis (Folk, Remington, & Johnston, 1992), states that goal directed search is not affected by target-irrelevant stimuli. In contrast, the distractor interference paradigm (Theeuwes, 1994), states that goal directed search can be affected by target-irrelevant stimuli if more salient than the rest of the search array. The study utilized a search array of contrast-equated orientation and spatial frequency modulated Gabor patches to preferentially activate the magnocellular and parvocellular visual streams in order to test for a magnocellular attentional advantage. Participants were asked to find a singleton target Gabor patch amongst a field of distractor Gabor patches. The results were mixed. Top-down search for a spatial frequency singleton provided support for the distractor interference paradigm while top-down search for an orientation singleton provided support for the contingent involuntary orientating hypothesis. These mixed results suggest top-down versus bottom-up search is more complicated than these two theories suggest. By demonstrating the effect of a target-irrelevant distractor on response time and accuracy, I provide that a bottom-up attentional priority exists when performing a top-down search for an orientation singleton, but not for a spatial frequency singleton. Additionally, the current study could find no evidence for a magnocellular attentional advantage.
Page Count
113
Department or Program
Department of Psychology
Year Degree Awarded
2016
Copyright
Copyright 2016, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
