Influence of rod adaptation upon cone responses to light offset in humans: I. Results in normal observers.

@article{citeulike:1572594, abstract = {Dark-adapted rods exert a tonic suppressive influence upon cone-mediated sensitivity to rapid flicker, a phenomenon called suppressive rod-cone interaction (SRCI). However, rod dark adaptation has negligible influence upon cone-mediated thresholds measured with more usual psychophysical procedures. The present study separately examined the influences of rod light and dark adaptation upon cone-mediated sensitivity to transient increases or decreases in illumination using sawtooth flicker with rapid-on (ramp-off) or rapid-off (ramp-on) waveforms. In the parafoveal retina, cones alone were stimulated with flicker by spatially superimposing long- and short-wavelength stimuli presented in counterphase and matched in scotopic illuminance. Several different adaptation procedures were used. For higher (greater than 4 Hz) frequencies, sensitivity of cones to both waveforms is nearly identical under any condition of adaptation; sensitivity decreases as rods progressively dark adapt. A considerably different situation exists for slower frequencies (1-4 Hz). Sensitivity of cones to rapid-off flicker is appreciably greater under light-adapted conditions confirming recent observations by Bowen et al. (1989). But as rods progressively dark adapt, sensitivity of cones to rapid-off waveforms decreases considerably while sensitivity to rapid-on waveforms is much less affected; in the totally dark-adapted eye, sensitivity to both waveforms is identical. These results confirm and extend recent physiological observations in amphibian retina (Frumkes \& Wu, 1990) suggesting that SRCI specifically involves responses to transient decreases in illumination.}, address = {Department of Psychology, Queens College of CUNY, Flushing 11367.}, author = {Frumkes, T. E. and Lange, G. and Denny, N. and Beczkowska, I. }, citeulike-article-id = {1572594}, issn = {0952-5238}, journal = {Vis Neurosci}, keywords = {rod\_cone}, month = {February}, number = {2}, pages = {83--89}, posted-at = {2007-08-17 15:42:42}, priority = {2}, title = {Influence of rod adaptation upon cone responses to light offset in humans: I. Results in normal observers.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/1558830}, volume = {8}, year = {1992} }

TY - JOUR ID - citeulike:1572594 L3 - citeulike-article-id:1572594 TI - Influence of rod adaptation upon cone responses to light offset in humans: I. Results in normal observers. JF - Vis Neurosci VL - 8 IS - 2 SP - 83 EP - 89 AD - Department of Psychology, Queens College of CUNY, Flushing 11367. SN - 0952-5238 N2 - Dark-adapted rods exert a tonic suppressive influence upon cone-mediated sensitivity to rapid flicker, a phenomenon called suppressive rod-cone interaction (SRCI). However, rod dark adaptation has negligible influence upon cone-mediated thresholds measured with more usual psychophysical procedures. The present study separately examined the influences of rod light and dark adaptation upon cone-mediated sensitivity to transient increases or decreases in illumination using sawtooth flicker with rapid-on (ramp-off) or rapid-off (ramp-on) waveforms. In the parafoveal retina, cones alone were stimulated with flicker by spatially superimposing long- and short-wavelength stimuli presented in counterphase and matched in scotopic illuminance. Several different adaptation procedures were used. For higher (greater than 4 Hz) frequencies, sensitivity of cones to both waveforms is nearly identical under any condition of adaptation; sensitivity decreases as rods progressively dark adapt. A considerably different situation exists for slower frequencies (1-4 Hz). Sensitivity of cones to rapid-off flicker is appreciably greater under light-adapted conditions confirming recent observations by Bowen et al. (1989). But as rods progressively dark adapt, sensitivity of cones to rapid-off waveforms decreases considerably while sensitivity to rapid-on waveforms is much less affected; in the totally dark-adapted eye, sensitivity to both waveforms is identical. These results confirm and extend recent physiological observations in amphibian retina (Frumkes & Wu, 1990) suggesting that SRCI specifically involves responses to transient decreases in illumination. KW - rod_cone AU - Frumkes, TE AU - Lange, G AU - Denny, N AU - Beczkowska, I PY - 1992/02// UR - http://view.ncbi.nlm.nih.gov/pubmed/1558830 ER -