Temporal binding, binocular rivalry, and consciousness

Cognitive functions like perception, memory, language, or consciousness are based on highly parallel and distributed information processing by the bra in. One of the major unresolved questions is how information can be integra ted and how coherent representational states can be established in the dist ributed neuronal systems subserving these functions. It has been suggested that this so-called ''binding problem'' may be solved in the temporal domai n. The hypothesis is that synchronization of neuronal discharges can serve for the integration of distributed neurons into cell assemblies and that th is process may underlie the selection of perceptually and behaviorally rele vant information. As we intend to show here, this temporal binding hypothes is has implications for the search of the neural correlate of consciousness . We review experimental results, mainly obtained in the visual system, whi ch support the notion of temporal binding. In particular, we discuss recent experiments on the neural mechanisms of binocular rivalry which suggest th at appropriate synchronization among cortical neurons may be one of the nec essary conditions for the buildup of perceptual states and awareness of sen sory stimuli. (C) 1999 Academic Press.