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Object‐based visual neglect: a computational hypothesis
Author(s) -
Deco Gustavo,
Rolls Edmund T.
Publication year - 2002
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.2002.02279.x
Subject(s) - posterior parietal cortex , neglect , visual field , object (grammar) , visibility , cortex (anatomy) , visual cortex , neuroscience , perception , psychology , contrast (vision) , visual perception , computer vision , cognitive psychology , computer science , artificial intelligence , physics , optics , psychiatry
Some patients with damage to the right parietal cortex show neglect for the left half of each of a series of objects shown in a horizontal row in the visual field. The neglect is thus not based on failure to see objects in any part of left visual space, but is object‐based. We show that in a model of attention with separate V1, object (inferior temporal cortex, IT) and spatial (posterior parietal cortex, PP) modules the effect can arise after graded damage increasing towards the right of the PP module when the lateral inhibition between neurons in the PP and V1 modules is short‐range. The local lateral inhibition produces high contrast effects at the edges of each object, and it is when this interacts with gradually increasing damage through the left visual field that the visibility of the left half of each object is especially impaired. This result was found in a formal model completely specified by mean field equations to quantify the dynamical interactions between the modules. This is the first quantitative account of object‐based neglect found in humans with right parietal cortex damage, and provides evidence that the model of attention we describe can account for even detailed and extraordinary phenomena that can occur in visual perception.