Dynamics of adaptation to contrast.
An investigation has been made into the temporal parameters with which the detection threshold for a sinusoidal grating changes during and after adaptation to the same grating at high contrast. Stationary high-spatial-frequency gratings and a phase-reversing low-spatial-frequency grating have been studied separately. It was found that the threshold continues to rise during adaptation for at least 6 min without sign of levelling off, and that full recovery from 6 min of adaptation can take more than 45 min. Intermittent adaptation and continuous adaptation for the same period produce similar effects. Single-phase and dual-phase exponential fits to the data are rejected, and it is concluded that the level of adaptation of the visual system to spatial contrast changes as a power function of time. However, recovery is not always monotonic, especially after adaptation to phase-reversing gratings. This may be due to inhibitory interactions between channels (in particular, those for pattern and movement information).
D000221:Adaptation, Ocular; D000293:Adolescent; D000328:Adult; D005260:Female; D005425:Flicker Fusion; D005556:Form Perception; D006801:Humans; D008297:Male; D009039:Motion Perception; D010364:Pattern Recognition, Visual; D012684:Sensory Thresholds; D013997:Time Factors