FEATURE PROCESSING AND ATTENTION IN THE HUMAN VISUAL-SYSTEM - AN OVERVIEW

A recent development in the cognitive modelling of visual selective at tention is the incorporation of design principles derived from the neu roanatomy and neurophysiology of the primate visual system. In this pa per, we describe these recent 'neurocognitive' models in more detail, point out the underlying neurobiological principles, and show that in all cases attention is implemented as an energetical resource which ca n be directed to representations and pathways in the system. In the se cond part of the paper, we specify the predictions derived from this ' energy hypothesis', and evaluate available data pertaining to this iss ue. We present new analyses of electrophysiological data in order to d irectly test the hypothesis that attention modulates feature-specific representations. It will be shown that in the case of sustained spatia l attention, the data are in agreement with this hypothesis, whereas i n the case of nonspatial attention, there is no evidence of a modulati on of feature-specific pathways by attention. (C) 1997 Elsevier Scienc e B.V.