Accession Number : ADP006080

Title :   Dissecting the Visual and Auditory Pathways by Means of the Two-Input Technique,

Corporate Author : DALHOUSIE UNIV HALIFAX (NOVA SCOTIA)

Personal Author(s) : Regan, D. ; Regan, M. P.

Report Date : FEB 1988

Pagination or Media Count : 9

Abstract : We describe an evoked potential technique for identifying the nonlinear characteristics of specialized sensory neural mechanisms in the human brain. For example, subjects viewed a grating pattern modulated at F1 Hz superimposed on a second grating modulated at F2 Hz. The VEP consisted of about 20 discrete frequency components, each of less than 0.004 Hz bandwidth. Most would be destroyed by conventional averaging, but could be measured by a zoom-FFT technique that gives 25,000 resolvable bins over DC-100 Hz. We have developed a mathematical treatment such that the pattern of behavior among these VEP components ''fingerprints'' the nonlinear processing. We report orientation tuning bandwidths (20 deg) and the spatial frequency tuning of a phase-independent visual mechanism; strong interactions between responses to orthogonal orientations; and a possible EP means of investigating the auditory hair cell transducer characteristic. (js)

Descriptors :   *SENSES(PHYSIOLOGY), BANDWIDTH, BEHAVIOR, BRAIN, CELLS, FINGERPRINTS, FREQUENCY, GRATINGS(SPECTRA), HAIR, HEARING, HUMANS, MATHEMATICAL ANALYSIS, MEAN, NERVOUS SYSTEM, NONLINEAR SYSTEMS, ORIENTATION(DIRECTION), ORTHOGONALITY, PATTERNS, PROCESSING, REPORTS, RESPONSE, SPATIAL DISTRIBUTION, TRANSDUCERS, TUNING.

Subject Categories : Psychology

Distribution Statement : APPROVED FOR PUBLIC RELEASE