Phantom and concrete motion after effects have different temporal tuning

Abstract

Using motion aftereffects (MAE), we quantified the adaptation produced by an expanding concentric ring stimulus. The rings had sinusoidal luminance modulations and were presented in a 5 -diameter aperture against a mean grey background. Two adapting stimuli were used: a concrete stimulus (complete circle) and a phantom stimulus (complete circle minus two horizontal grey 40 -arc sectors either side of the mid-line). After adaptation, subjects indicated if test gratings presented for 0.4s in 30 -arc horizontal sectors were expanding (+) or contracting (-). The subjects adapted for 30s, then indicated the motion direction in 32 tests interleaved with 5s top-up adaptation periods. Adapting tempo..