On the time course of perceptual information that results from a brief visual presentation.
A briefly presented visual stimulus engenders an available-information function that lags behind the physical stimulus. We report two experiments that focus on the iconic-decay portion of this function, which falls to 0 over a 200-300 ms period following stimulus offset. In each experiment, to-be-reported digit strings were shown for varying durations followed by a noise mask at varying poststimulus intervals. We found the shape of the performance curve relating digit-report probability to stimulus exposure duration to be independent of stimulus-mask interstimulus interval. This finding is consistent with the proposition that the iconic-decay function's shape is independent of stimulus duration and allows us to identify this shape. We rejected exponential iconic decay for 6 of 8 observers; however, all observers' decay functions could be adequately fit by gamma decay, a generalization of exponential decay.
Loftus
G R
GR
Department of Psychology, University of Washington, Seattle 98195.
Duncan
J
J
Gehrig
P
P
D000328:Adult; D001288:Attention; D004193:Discrimination Learning; D005260:Female; D005366:Figural Aftereffect; D006801:Humans; D007206:Individuality; D008297:Male; D011939:Mental Recall; D010364:Pattern Recognition, Visual; D010470:Perceptual Masking; D011601:Psychophysics; D011930:Reaction Time