BRIGHTNESS FADING DURING GANZFELD ADAPTATION

The time course and extent of brightness fading in a Ganzfeld were det ermined for adapting luminances ranging from 0.01 to 100 cd/m(2). Magn itude estimation and interocular brightness matching were used. During Ganzfeld adaptation, perceived brightness decreased slowly and levell ed off, on average, after 5-7 min (adapting time increasing with lumin ance). On average, the total brightness loss was equivalent to a 1.2 l og unit reduction in luminance, independent of adapting luminance. The residual brightness perceived at the final plateau was generally high er than the brightness of the Eigengrau, suggesting a partially sustai ned luminance channel. (C) 1997 Optical Society of America.