title: The time course of contrast adaptation measured with a new method: detection of ramped contrast.
abstract: The present study introduces a new method to measure contrast detection thresholds before and after adaptation to contrast. A sinusoidal testing grating increased contrast at a constant rate from an initial subthreshold level. Subjects indicated when the grating was just visible, which terminated its presentation. The stimulus contrast at the time of response was taken as a measure of relative threshold. We used the method to measure the time courses of changes in threshold following adaptation, for several adapting contrasts (9, 19, 29, or 39 dB, ref. 1%) and adapting durations (10, 100, or 1000 s). The buildup and decay of adaptation to contrast was described well by a power function of time. These results agree with previous findings, but are more efficient in terms of subject time. This method promises to be a useful tool for studying the dynamics of adaptation to spatial contrast.
authors.forename: Xue
authors.initials: X
authors.lastname: Dong
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Engel
authors.forename: Min
authors.initials: M
authors.lastname: Bao
mesh_terms: D000221:Adaptation, Ocular; D000328:Adult; D015350:Contrast Sensitivity; D004193:Discrimination Learning; D005260:Female; D005366:Figural Aftereffect; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual; D011601:Psychophysics; D011930:Reaction Time; D012684:Sensory Thresholds