Description
- Abstract:
- Key functions of human vision are the perception of one’s environment and interaction with it. Here we investigate the relation between visual perception and visually-guided action through the use of stimulus size perception, and hand and eye movement tracking paradigms. In Chapter 1 we manipulated stimulus image size, or the visual size a stimulus was presented, and illusory size, the non-veridical size a stimulus appeared within the Ponzo illusion, and examined how each influenced pointing hand movements and saccadic eye movements. We found that when hand and eye movements were performed in isolation they displayed the same pattern of influence, namely that movement preparation but not movement execution was susceptible to the illusion. However, when the two were coordinated in a more naturalistic manner, the illusion influenced saccade preparation and execution, but ceased to influence pointing movements. Thus, we propose that a shared effector-general mechanism modulates illusion’s influence on both action types, but is dominated by eye movements. Thus, perception and action are integrated not just such that illusion influences action, as has been contested in the past, but the relationship between the two is dynamic and varies based on task demands. In Chapter 2 we manipulated the image sizes of real world objects, which also have intrinsic familiar sizes, or sizes that we know the objects to be in the real world based on prior knowledge. When objects’ relative image and familiar sizes were incongruent we observed conflict such that image size impaired performance on the familiar size task and vice versa. Thus, each is processed automatically, even when task-irrelevant. That said, image size was consistently processed earlier and more robustly than familiar size. However this effect was mitigated by greater familiar size difference magnitudes. Thus, there again was a dynamic interaction between these two forms of perception and action, based on task demands. Image size, illusory size, and familiar size represent increasingly complex levels of visual perception. Here we demonstrate reciprocal interactions within levels of visual processing, and that each level of processing additionally interacted with action.
- Notes:
- Thesis (Ph. D.)--Brown University, 2019
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Citation
Gamble, Christine Marie,
"The dynamic interplay between target size perception and visually-guided action"
(2019).
Cognitive, Linguistic, and Psychological Sciences Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.26300/kezj-sh50
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Cognitive, Linguistic, and Psychological Sciences Theses and Dissertations
Theses and Dissertations for the Cognitive, Linguistic, and Psychological Sciences department....