Visual orientation and its contributions to perception, attention and working memory

Frank Tong

Frank Tong

(Vanderbuilt)

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Date: May 4, 2016

Description:

Orientation is a fundamental feature that underlies how we see, make sense of, and imagine the visual world. In this talk, I will describe behavioral, computational, and neuroimaging research that demonstrates how the study of orientation processing can provide a window into mechanisms of perception, attentional selection and visual working memory. In recent fMRI work, we find that the earliest site of orientation processing takes place in the human lateral geniculate nucleus, where modest but reliable orientation responses can be found (Ling, Pratte & Tong, Nat Neurosci, 2015). Attentional feedback, presumably from cortical sources, can modify the strength of orientation-selective responses in the LGN. Activity patterns in cortical visual areas also reveal strong correspondences with perception, including the well-known tilt illusion and the oblique effect. Our behavioral and neuroimaging investigations further demonstrate how orientations are represented in visual working memory, and how the precision and capacity of working memory is highly dependent upon the nature of these stimuli. By incorporating orientation processes into computational models of visual working memory, we go on to show how stimulus-specific representations are important for discerning between discrete-item and continuous-resource models of working memory.




Created: Thursday, May 5th, 2016