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Invariant Visual Responses From Attentional Gain Fields EMILIO SALINAS AND L. F. ABBOTT

Summary: Invariant Visual Responses From Attentional Gain Fields
Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02254-9110
Salinas, Emilio and L. F. Abbott. Invariant visual responses from of their receptive fields, in several cases the responses were
attentional gain fields. J. Neurophysiol. 77: 32673272, 1997. In- shown to increase as attention was directed further away
ferotemporal (IT) neurons exhibit a substantial degree of invari- from the receptive field center. Interestingly, the preferred
ance with respect to translation of images used as visual stimuli. attentional loci were found in directions that appear to be
Through theoretical and computer-modeling methods, we show
unrelated to the preferred orientations or receptive field loca-how translation-invariant receptive fields, like those of IT neurons,
tions of the cells and that are uniformly distributed (Connorcan be generated from the responses of V4 neurons if the effects of
et al. 1996, 1997). As will be shown below, this surprisingattention are taken into account. The model incorporates a recently
feature is the crucial element that allows V4 neurons toreported form of attention-dependent gain modulation in V4 and
generate object-centered receptive fields further down theproduces IT receptive fields that shift so they are centered at the
point where attention is directed. Receptive fields of variable, atten- visual processing stream.
tion-controlled spatial scale are obtained when the mechanism is
Modelextended to scale-dependent attentional gain fields. The results
indicate that gain modulation may play analogous roles in the Our model consists of a population of V4 neurons driving
dorsal and ventral visual pathways, generating transformations
a single model IT neuron through feed-forward synaptic con-from retinal coordinates to body- and object-centered systems, re-
nections. In accordance with the data, the firing rates of thespectively.


Source: Abbott, Laurence - Center for Neurobiology and Behavior & Department of Physiology and Cellular Biophysics, Columbia University


Collections: Biology and Medicine