This volume contains chapters derived from a N. A. T. O. Advanced Study Institute held in June 1983. As the director of this A. S. I. it was my hope that some of the e1ectrophysiologists could express the potentialities of their work for perceptual theory, and that some perceptionists could speculate on the underlying "units" of perception in a way that would engage the imagination of physio logists. The reader will have to be the judge of whether this was achieved, or whether such a psychophysiological inter1ingua is still overly idealistic. It is clear that after the revolution prec pitated...