Interactions between attention, context and learning in primary visual cortex

Attention in early Visual processing engages the higher order, context depe ndent properties of neurons. Even at the earliest stages of visual cortical processing neurons play a role in intermediate level vision - contour inte gration and surface segmentation. The contextual influences mediating this process may be derived from long range connections within primary visual. c ortex (V1). These influences are subject to perceptual learning, and are st rongly modulated by visuospatial attention, which is itself a learning depe ndent process. The attentional influences may involve interactions between feedback and horizontal connections in V1. V1 is therefore a dynamic and ac tive processor, subject to top-down influences. (C) 2000 Elsevier Science L td. All rights reserved.