Abstract
Abstract: :
Purpose: Previous work suggests that perceptual learning of position discrimination is eye–specific when the untrained eye was patched, implying that the learning may occur in monocular neurons. We hypothesize that this "monocular" learning is learning to see through rivalry (learning to ignore the patch since the patch could produce interfering noise). We asked whether learning transfers from the trained eye to the untrained fellow eye under conditions where both eyes are open during learning. Methods: A Vernier alignment task was used with two line segments separated by a 17 arcmin gap. Each segment consisted of eight Gabor patches (carrier spatial frequency, 10 cpd) with 11 arcmin of separation between each patch. A method of constant stimuli was used, and the observer’s task was to indicate the position of the misaligned stimulus. To determine eye–specificity of learning, one group of observers’ (9) non–dominant eyes were patched while the dominant eyes were repetitively trained. A second group of observers (4) were trained with both eyes open, but with a diffuser over the open untrained eye to blur the visual perception. Each observer had 3200 trials by the end of experiment. Results: Following training with a patch on the untested eye, position discrimination performance improved significantly by 26%, from 0.73 to 0.54 arcmin (p<0.001). Before and after training, we tested the untrained eye and found that there was no statistically significant improvement between pre (0.70 arcmin) and post (0.68 arcmin) performance (p>0.05). In contrast, with a diffuser on the untested eye, we found that learning effect completely transferred to the fellow untrained eye. The threshold improvements were almost the same (24%) in both trained and untrained eyes. Conclusions: Our findings suggest that "monocular" learning of position discrimination is due to learning to see through rivalry.
Keywords: learning • detection • visual cortex