Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-11T00:44:07.182Z Has data issue: false hasContentIssue false

Influence of rod adaptation upon cone responses to light offset in humans: II. Results in an observer with exaggerated suppressive rod–cone interaction

Published online by Cambridge University Press:  02 June 2009

Gudrun Lange
Affiliation:
Department of Psychology, Queens College of CUNY, Flushing New York
Thomas E. Frumkes
Affiliation:
Department of Psychology, Queens College of CUNY, Flushing New York

Abstract

In normal observers, sensitivity of cones to rapid sinusoidal flicker decreases by about 0.7 log units as rods progressively dark adapt. However, Arden and Hogg (1985) described a night-vision disorder characterized by normal rod sensitivity but exaggerated suppressive rod-cone interaction (SRCI). We refer to this condition as the exaggerated SRCI syndrome (ESS). The present paper examines the influence of rod-adaptation upon cone-mediated responses to light onset and offset in an observer with ESS. Under all conditions of adaptation examined, sensitivity of cones to rapid-on waveforms is indistinguishable to that of a normal observer tested under identical circumstances; rod sensitivity is also normal. However, the sensitivity of cones to transient decreases in illumination is clearly subnormal under light-adapted conditions. This deficit in cone responsiveness to light offset becomes increasingly subnormal as rods dark adapt and, when completely dark adapted, the ESS observer is nearly blind to 1 Hz rapid-off sawtooth waveforms. These results strongly bolster previous results that suggest that suppressive rod-cone interaction is restricted to the response to transient decreases in illumination.

Type
Research Articles
Copyright
Copyright © Cambridge University Press 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arden, G. B. & Hogg, C. R. (1985). A new cause for difficulty in seeing at night. Documenta Ophthalmologica 60, 121125.CrossRefGoogle ScholarPubMed
Carr, R. E. (1969). The night-blinding disorders. Electrical Responses of the Visual System 9, 9711003.Google ScholarPubMed
Delange, H. (1954). Relationship between critical flicker frequency and a set of low-frequency characteristics of the eye. Journal of the Optical Society of America 44, 380389.CrossRefGoogle Scholar
Frumkes, T. E. & Eysteinsson, T. (1988). The cellular basis for suppressive rod-cone interaction. Visual Neuroscience 1, 263273.CrossRefGoogle ScholarPubMed
Frumkes, T. E., Lange, G., Denny, N. & Beczkowska, I. (1992). Influence of rod adaptation upon cone-responses to light offset in humans: I. Results in normal observers. Visual Neuroscience 8, 8389.CrossRefGoogle ScholarPubMed
Frumkes, T. E. & Wu, S. M. (1990). Independent influences of rod adaptation on cone-mediated responses to light onset and offset in distal retinal neurons. Journal of Neurophysiology 64, 10431054.CrossRefGoogle ScholarPubMed
Nygaard, R. W. & Frumkes, T. E. (1985). Frequency dependence in scotopic flicker sensitivity. Vision Research 25, 115127.CrossRefGoogle ScholarPubMed