The purpose of the current thesis was to investigate the role of gaze direction, when making preference decisions. Previous research has reported a progressive gaze bias towards the preferred stimuli as participants near a decision, termed the gaze cascade effect (Shimojo, Simion, Shimojo & Scheir, 2003). The gaze cascade effect is strongest during the final 1500 msec prior to decision (Shimojo et al.). Previous eye-tracking research has displayed natural viewing biases towards the upper visual field. However, previous investigations have not investigated the impact of image placement on the gaze cascade effect. Study 1 investigated the impact of presenting stimuli vertically on the gaze cascade effect. Results indicated that natural scanning biases towards the upper visual field impacted the gaze cascade effect. The gaze cascade effect was reliably seen only when the preferred image was presented in the upper visual field. Using vertically paired stimuli study 2 investigated the impact of choice difficulty on the gaze cascade effect. Similar to study 1 the gaze cascade effect was only reliably seen when the preferred image was presented in the upper visual field. Additionally choice difficulty impacted the gaze cascade effect where easy decisions displayed a larger gaze cascade effect than hard decisions. Study 3 investigated if the gaze cascade effect is unique to preference decisions or present during all visual decisions. Judgments of concavity using perceptually ambiguous spheres were used and no gaze cascade effect was observed. Study 3 indicated that the gaze cascade effect is unique to preference decisions. Results of the current experiments indicate the gaze cascade effect is qualified by the spatial layout of the stimuli and choice difficulty. Results of the current experiments are consistent with previous eye-tracking research demonstrating biases towards the upper visual field and offering support for Prevics theory on how we interact in visual space.
Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-03262010-151736 |
Date | 08 April 2010 |
Creators | Burkitt Hiebert, Jennifer Ann |
Contributors | Crossley, Margaret, Friesen, Chris Kelland, Elias, Lorin, Borowsky, Ron, Farthing, Jon |
Publisher | University of Saskatchewan |
Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
Language | English |
Detected Language | English |
Type | text |
Format | application/pdf |
Source | http://library.usask.ca/theses/available/etd-03262010-151736/ |
Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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