Authors:

DUNCAN, J.

Reference:

Year of publication:

2000

CBU number:

3771

Abstract:

This tutorial deals with behavioural and brain level analyses of visual attention. In the first part, some of the major principles established in the past 40 years of behavioural studies are reviewed. Studies of divided attention show parallel, object-based competition influencing explicit identification of most or all visual features. Studies of selective attention, including visual search and partial report, show that competition is biased by behavioural context, the effectiveness of this bias depending on the ease of discriminating relevant and irrelevant inputs. Together these principles may be regarded as constraints shaping an overall theory, and indeed they are aptly captured by Bundesen's (1990) quantitative Theory of Visual Attention or TVA. The second part of the chapter deals with neural implementation. It is suggested that concurrent inputs compete to be processed in many separate brain systems, sensory and motor, cortical and subcortical. This competition is biased by priming of cells responsive to current behavioural targets, and integrated such that, as the sensorimotor network settles into a stable state, the same object assumes dominance throughout. Neurophysiological and neuropsychological data in support of these proposals are reviewed.