Subject: cross-modal interactions From: Robert Zatorre <MD37(at)MUSICA.MCGILL.CA> Date: Mon, 9 Feb 1998 15:01:26 -0500For some interesting behavioral as well as neurophysiological evidence pertaining to auditory visual interactions, see the following: Stein, B.E., Wallace, M.T. and Meredith, M.A. (1995) Neural mechanisms mediating attention and orientation to multisensory cues. In The Cognitive Neurosciences, M. Gazzaniga Ed., MIT press, Cambridge, Mass., pp. 683-702. Knudsen, E.I. and Brainard, M.S. (1995) Creating a unified represenation of visual and auditory space in the brain. Annual Review of Neuroscience, 18, 19-43. These studies have shown that under at least some conditions, stimuli that are subthreshold in one or the other modality alone can be responded to when they're combined, hence demonstrating some nonlinear interactions. Stein and colleagues have provided neurophysiological evidence that neurons within the deep layers of the feline superior colliculus contain topographic maps of both visual and auditory space, and that large enhancements of response are observed to combined auditory and visual stimulation; this structure may therefore be one substrate for integration of the two modalities. In addition, it has been shown that inputs from unimodal neurons within polysensory cortical areas are important determinants of SC integration of response. -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Robert J. Zatorre, Ph.D. Montreal Neurological Institute 3801 University St. Montreal, QC Canada H3A 2B4 phone: 1-514-398-8903 fax: 1-514-398-1338 e-mail: md37(at)musica.mcgill.ca