Figure 3.

Schematic of early visual system channels and the changes with perceptual learning. A Gabor patch in noise is processed by visual channels tuned to different spatial frequencies and orientations (14). Channels tuned to a range of spatial frequencies and their corresponding bandpass stimuli are illustrated. Each channel has additive and multiplicative noise as well as nonlinearities. Early in training, several channels are active and connected to a decision structure. After training, the most closely tuned channel has the most active inputs to a decision module, whereas that of other channels has been reduced.