Slide 22

Protocol for Examining the Cellular Mechanisms of Receptive Field Changes During Artificial Scotomas

The possible changes in receptive field structure were examined in one dimension by mapping the receptive field with randomly flashed black or white bars (for ON and OFF subregions) before and after various whole field stimuli. First, we presented a uniform gray screen, followed by 3 seconds of receptive field mapping. This was followed by an artificial scotoma that covered much more than the "classical" receptive field for approximately 30 seconds. The receptive field was then mapped again. This was followed by whole field stimulation with a sinewave grating at high contrast. Again the receptive field was mapped. Finally, the cell was again exposed to the artificial scotoma.

Note that the animal is presented with the identical stimulus (an artificial scotoma) after two different stimuli: following a uniform gray screen and following the whole field sinewave grating.