Accession Number:

AD0733613

Title:

Rapid Changes and Hysteresis in Spatial Integration for Human Rod Vision,

Descriptive Note:

Corporate Author:

TORONTO UNIV (ONTARIO) DEPT OF PHYSIOLOGY

Personal Author(s):

Report Date:

1970-08-17

Pagination or Media Count:

15.0

Abstract:

Two previous papers Hallett, 1969a, b were concerned with the visual threshold appropriate to a peripheral retinal point and in particular with the rapid changes in point threshold produced by illuminating the dark-adapted eye with large brief duration backgrounds. This paper extends this approach to testing signals of larger subtense. Spatial integration for the rods can rapidly diminish and recover within a few hundred milliseconds. A brief duration background which raises the threshold at a retinal point as much as some steady background is more effective than the steady background in reducing the extent of spatial integration. Hysteresis can be substantial the extent of spatial integration varies, even for a given point threshold, according to whether the threshold is rising or falling, or temporarily or permanently steady. Author

Subject Categories:

  • Psychology
  • Anatomy and Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE