Time course of early mesopic adaptation to luminance decrements and recovery of spatial resolution.
The time course of recovery of spatial resolution following adaptation to a uniform field was measured for test probes presented at lower illuminance than the adapting field. Six observers were tested in a Maxwellian-view system using 20 degrees adapting fields of 1.6-2.6 log photopic trolands. Test stimuli were 7 degrees, 250 ms Gabor patches (1 and 6 cpd) of mean retinal illuminance 2-3 log units lower than the adapting field. During the 9 s after adapting field offset, contrast thresholds for orientation discrimination followed an exponential-decay function and showed longer recovery times for larger illuminance decrements and higher spatial frequency.
Howard
C M
CM
Link Simulation and Training Division, L-3 Communications, 6030 S. Kent, 85212-6061, Mesa, AZ, USA. celeste.howard@williams.af.mil
Tregear
S J
SJ
Werner
J S
JS
D000328:Adult; D000367:Age Factors; D015350:Contrast Sensitivity / Q000502:physiology*; D003623:Dark Adaptation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013028:Space Perception / Q000502:physiology; D013997:Time Factors; D014792:Visual Acuity / Q000502:physiology