Consciousness and the neurobiology of perceptual binding.
Seminars in neurology June 1, 1997 V G Hardcastle
The brain processes information along specialized tracts separated across the cortex, yet visual experiences are of unified objects. How perceptions become united into wholes despite distributed features is the problem of perceptual binding. This article reviews neurophysiological research connecting perceptual awareness with 40 Hz neural oscillatory firing patterns, examining three experimental approaches: single-cell and local field potential recordings in visual areas 17 and 18 showing synchronous firing between noncontiguous cells with similar receptive fields; MEG measurements of rapid thalamic bursting suggesting the ILN might drive cortical oscillations; and EEG recordings over sensory areas indicating higher-level neural coordination. As of this writing, a connection between any 40 Hz oscillatory patterns and perceptual binding or consciousness is tenuous at best.