Geraint Rees

Imaging the NCC

Abstract

The immediacy and directness of conscious experience belies the complexity of the underlying neural mechanisms, which remain incompletely understood. I will review some examples of our recent functional magnetic resonance imaging studies in normal subjects and patients with focal cortical lesions, which provide new insights into the mechanisms involved. These data complement behavioral, neuropsychological and electrophysiological findings by suggesting that activity in functionally specialized areas of ventral visual cortex is necessary for visual awareness. However, our recent work suggests that activity in ventral occipital and temporal cortex is not sufficient to support conscious vision without a contribution from parietal and prefrontal areas. Such a contribution may reflect processes such as selective attention and working memory. Reciprocal interactions between parietal and ventral visual cortex may thus serve to selectively integrate internal representations of visual events in the broader behavioral context in which they occur, leading to the richness of our conscious experience and providing a fundamental neural substrate for conscious visual experience.