Browsing by Author "Brown, James Michael"

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    Is Gloss a cue for Real-World Object Size?
    Brown, James Michael (Virginia Tech, 2020-08-10)
    Two separate lines of research in object recognition are studies of materials perception and studies of real-world object size perception. Recent object size investigations of texture indicate mid-level features may cue representations of object size in the absence of object identity. However, these findings are somewhat controversial, and beyond that what mid-level features cue object size is not clear. Mid-level features have always been the focus of materials perception studies of gloss and specular highlights, but to date no research has been conducted that attempts to link findings on the perception of materials to high-level object features like real-world object size. Three separate experiments were conducted to study the relationship between perceived surface glossiness and specular highlights, and perceived real-world object size. Previous research on the relationship between perceived object size and real-world object size were replicated. A significant two-way interaction between ratings of perceived glossiness, object size, and texture was found. Follow-up analyses indicated that perceptions of gloss were present across categorical differences in real-world object size in both the object image and texture image task groups. For the normal object images, small objects were perceived as being glossier than big objects. For the texture images, big objects were perceived as being glossier than small objects. Between the conditions, small normal and small texture object images were not significantly different in perceived glossiness. Between the conditions, glossiness ratings for big texture object images were significantly greater than those for the normal big object images.
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    Perceived Size Modulates Cortical Processing of Objects
    Brown, James Michael (Virginia Tech, 2015-12-18)
    Empirical object recognition research indicates that objects are represented and perceived as hierarchical part-whole arrangements that vary according to bottom-up and top-down biases. An ongoing debate within object recognition research concerns whether local or global image properties are more fundamental for the perception of objects. Similarly, there is also disagreement about whether the visual system is guided by holistic or analytical processes. Neuroimaging findings have revealed functional distinctions between low and higher-level visual processes across lateral occipital-temporal cortex (LOC), primary visual cortices (V1/V2) and ventral occipital-temporal cortex. Recent studies suggest activations in these object recognition areas and others, such as the fusiform face area (FFA) and extra-striate body area (EBA), are collinear with activations associated with the perception scenes and buildings. Together, this information warrants the focus of the proposed study: to investigate the neural correlates of object recognition and perceived size. During the experiment subjects tracked a fixation stimulus while simultaneously being presented with images of shape contours and faces. Contours and face stimuli subtended small, medium and large visual angles in order to evaluate variance in neural activation across perceived size. In the present study visual areas were hypothesized to modulate as a function of visual angle, meaning that the part-whole relationships of objects vary with their perceived size.