Temporal Tuning Effects in the Visually Evoked Response,
Abstract
Electrophysical and psychophysical evidence indicates that there channels in the visual system that are more sensitive to either spatially- structured stimuli or luminance-modulated stimuli. This sensitivity or tuning was demonstrated by having the largest or optimum response produced by either spatially-structured or luminance-modulated stimuli. The purpose of this study is to determine if the steady-state visually evoked response to three stimuli is significantly and predictably altered by the choice of temporal frequency. It is expected that, for each observer, there will be an optimal temporal frequency or frequencies corresponding to a given pattern size, contrast and intensity. Also, this relationship will likely vary between individuals, but will remain relatively constant for a given observer over time. Three subjects were each presented with three stimuli. These stimuli were: (1) a square pattern of small checks where each check subtended 15 minutes of arc; (2) a square pattern of large checks where each check subtended 57 minutes of arc; and, (3) an unpatterned square stimulus. The check stimuli were presented in such a manner that alternate checks were 180 deg out of phase with each other and the unpatterned stimulus was presented as a luminance charge.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1985
- Accession Number
- ADA168219
Entities
People
- Ralph E. Parkansky
Organizations
- Naval Aerospace Medical Research Laboratory