Dissertation
The architecture of the priority map used to guide visual attention
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Autumn 2019
DOI: 10.17077/etd.005249
Abstract
The eyes are the human brain’s primary portal on the external world. A few times each second, the eyes are shifted to a new location in the world to gather precise visual information about objects of interest. Such shifts of visual attention have been best understood using the notion of a priority map. Priority maps are winner-take-all mechanisms of attentional selection, with activity in the map corresponding to the extent to which a location is prioritized for selection. Here, I used the proposed architectures of specific priority map instantiations to develop predictions that were evaluated across several experiments. These experiments provide novel evidence that challenge several of the core assumptions made by models of attentional priority, with wide reaching theoretical implications. In particular, these experiments advance our understanding of how different sources of top-down priority interact, how such priority changes over the duration of a visual search, and how multiple representations in VWM interact with priority. In addition to providing evidence regarding the basic scientific question of the architecture underlying top-down shifts of visual attention, this thesis also has broad real-world applications. This is because many important real-world tasks are search tasks, such as security screeners looking for dangerous items in luggage at the airport. By better understanding visual attention, we can better understand how important real-world tasks are performed and could potentially be optimized.
Details
- Title: Subtitle
- The architecture of the priority map used to guide visual attention
- Creators
- Brett Bahle
- Contributors
- Andrew Hollingworth (Advisor)Eliot Hazeltine (Committee Member)Cathleen Moore (Committee Member)J Toby Mordkoff (Committee Member) - University of Iowa, Psychological and Brain SciencesShaun Vecera (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Psychology
- Date degree season
- Autumn 2019
- DOI
- 10.17077/etd.005249
- Publisher
- University of Iowa
- Number of pages
- ix, 204 pages
- Copyright
- Copyright 2019 Brett Bahle
- Comment
- This thesis has been optimized for improved web viewing. If you require the original version, contact the University Archives at the University of Iowa: https://www.lib.uiowa.edu/sc/contact/
- Language
- English
- Description illustrations
- illustrations (some color)
- Description bibliographic
- Includes bibliographical references (pages 194-204)
- Public Abstract (ETD)
About three times per second, the human eyes shift to a new position in order to gather information about potentially relevant objects in the world. What determines which objects the eyes orient to? I investigated this question by having people perform visual search tasks. In one set of experiments, participants searched for objects in computer images of real-world scenes, allowing me to examine how different sources of information interact to determine which objects are selected by the eyes’ orienting behavior. I found that people preferentially rely on information about their search object’s features (e.g., that keys are silver) over the search target’s likely contextual location in the scene (e.g., that keys usually belong on counter-tops) or its previously observed location (e.g., I remember I found my keys on the counter by the front door).
In another set of experiments, I examined whether it is possible to look for two objects at once. For example, is it possible to simultaneously look for both your keys and your phone? I examined this question in two ways. First, I had people search for a particular shape (e.g., a triangle) among other shapes (e.g., squares, crosses, and circles) while simultaneously remembering a color (e.g., red). In this task, search was efficient, but the presence of a shape that matched the color they were remembering impaired performance. Second, I had people search for the presence of two colors simultaneously (e.g., red and blue) among a set of other colors. Responses on trials with both target colors present produced responses that were much faster than when only one of the target colors was present. The results from this latter set of experiments suggests people can look for two objects at once.
In sum, the present experiments inform the basic scientific question about what determines where we look, while also having practical implications for improving real-world search tasks such as baggage screening and x-ray image analysis.
- Academic Unit
- Psychological and Brain Sciences
- Record Identifier
- 9983779999302771
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