Eye movement and the visual perception of shape

This thesis reports the results of five novel studies that used eye movement patterns to elucidate the role of shape information content of object shape representation in human visual perception. In Experiments 1, and 2 eye movements were recorded while observers either actively memorised or passively viewed different sets of novel objects, and during a subsequent recognition memory task. ..• -'", ••. Fixation data were contrasted against different models of shape mralyses based on surface curvature bounding vs. internal contour and low level image visual saliency. The results showed a preference for fixation at regions of internal local features (either concave or/and convex) during both active memorisation and passive viewing of object shape. This pattern changed during the recognition phase where there was a fixation preference towards regions containing concave surface curvature minima. It is proposed that the preference of fixation at regions of concavity reflect the operation of a depth-sensitive view interpolation process that is constrained by key points encoding regions of concave curvature minima. Experiments 3 and 4 examined the extent to which fixation-based local shape analysis patterns are influenced by the perceptual expertise of the observer and the level of stimulus classification required by the task. These studies were based on the paradigm developed by Wong, Palmeri & Gauthier (2009) in which observers are extensively trained to categorize sets of novel objects (Ziggerins) at either a basic or subordinate level of classification. The effects of training were measured by comparing performance between a pre- and post-test sequential shape matching task that required either basic- or subordinate-level judgements. In addition, we also recorded fixation patterns during the pre- and post-tests.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Eye movement and the visual perception of shape

This thesis reports the results of five novel studies that used eye movement patterns to elucidate the role of shape information content of object shape representation in human visual perception. In Experiments 1, and 2 eye movements were recorded while observers either actively memorised or passively viewed different sets of novel objects, and during a subsequent recognition memory task. ..• -'", ••. Fixation data were contrasted against different models of shape mralyses based on surface curvature bounding vs. internal contour and low level image visual saliency. The results showed a preference for fixation at regions of internal local features (either concave or/and convex) during both active memorisation and passive viewing of object shape. This pattern changed during the recognition phase where there was a fixation preference towards regions containing concave surface curvature minima. It is proposed that the preference of fixation at regions of concavity reflect the operation of a depth-sensitive view interpolation process that is constrained by key points encoding regions of concave curvature minima. Experiments 3 and 4 examined the extent to which fixation-based local shape analysis patterns are influenced by the perceptual expertise of the observer and the level of stimulus classification required by the task. These studies were based on the paradigm developed by Wong, Palmeri & Gauthier (2009) in which observers are extensively trained to categorize sets of novel objects (Ziggerins) at either a basic or subordinate level of classification. The effects of training were measured by comparing performance between a pre- and post-test sequential shape matching task that required either basic- or subordinate-level judgements. In addition, we also recorded fixation patterns during the pre- and post-tests.EThOS - Electronic Theses Online ServiceGBUnited Kingdo