A Neural Theory of Visual Attention: Bridging Cognition and Neurophysiology.

Abstract

A neural theory of visual attention (NTVA) is presented. NTVA is a neural interpretation of C. Bundesen's (1990) theory of visual attention (TVA). In NTVA, visual processing capacity is distributed across stimuli by dynamic remapping of receptive fields of cortical cells such that more processing resources (cells) are devoted to behaviorally important objects than to less important ones. By use of the same basic equations used in TVA, NTVA accounts for a wide range of known attentional effects in human performance (reaction times and error rates) and a wide range of effects observed in firing rates of single cells in the primate visual system. NTVA provides a mathematical framework to unify the 2 fields of research--formulas bridging cognition and neurophysiology.

The neural basis of attentional control in visual search

“…The existence of correlations between the target-selectivity of preparatory pre-stimulus activation patterns in visual cortex and the quality of subsequent target detection performance [10,[12][13][14]16] suggests that preparatory modulations of visual activity might indeed act as attentional templates that are causally involved in the control of visual search. However, this conclusion is by no means universally accepted [17][18][19]. When the location of targets is uncertain, target-selective visual activation patterns elicited during the preparation for visual search should represent search goals in a position-independent fashion (Box 1).…”

“…This sustained negativity is equivalent to the CDA component observed during the delay period of working memory tasks [58], and its presence during the identification of target objects in visual search demonstrates the involvement visual working memory [18,59].…”

“…The biased competition model of visual attention [5] assumes that feature-selective attentional biases generated at particular levels of the visual processing hierarchy during the guidance phase trigger competitive advantages for possible target objects, and these are then propagated in a spatially selective fashion to lower and higher levels. Other models [18,40] postulate dedicated 'source' areas of attentional control where task-relevant locations are represented, 'sites' of spatially selective processing in visual areas, and recurrent pathways (see Box 2) from source to site regions. In these models, the allocation of spatial attention is controlled by priority maps [40,41] in posterior parietal cortex [42], the frontal eye fields (FEF) [43], or the thalamus [18].…”

“…Other models [18,40] postulate dedicated 'source' areas of attentional control where task-relevant locations are represented, 'sites' of spatially selective processing in visual areas, and recurrent pathways (see Box 2) from source to site regions. In these models, the allocation of spatial attention is controlled by priority maps [40,41] in posterior parietal cortex [42], the frontal eye fields (FEF) [43], or the thalamus [18]. Priority maps send recurrent top-down control signals to visual cortex, where they elicit spatially specific enhancements of visual responses to possible target objects.…”

“…Analogous spatially global feature-based attentional Because feature-based attentional modulations of visual processing operate in a spatially global fashion, they can provide guidance signals for the subsequent allocation of spatial attention to candidate target objects. Models of visual attention [18,24] postulate that during the parallel analysis of visual input, processing is selectively weighted in favor of target-defining features. The neural mechanisms of feature-based attention can implement such task-dependent attentional biases in a spatially global fashion across the visual field.…”