Cat Contrast To Identify The Neural Mechanisms Of Perceptual Learning

Perceptual learning is a very hot topic in the research field of learning. Because of its specificity, it has been thought that it maybe occurs in some lower cortex. The research of perceptual learning may disclose the principle neural mechanism of learning, and will improve our understanding of plasticity of adult brain.This article is mainly about the neural mechanism of perceptual learning. The first part of the article summarizes the research situation about the perceptual learning. Based on different research methods —the psychophysics, the single-unit recording, the VEP and the fMRI, we try to understand two principle questions about perceptual learning: one is that where the perceptual learning occurs and the other is that how the perceptual learning occurs. As to the first question, many researches suggest that perceptual learning maybe occurs in some lower cortex based on the specificity of learning effect. And many experiments, including electrophysiological experiments, VEP and fMRI 's results also support this opinion. But some other experiments suggest that the perceptual learning maybe occur in some higher cortex. As to the other question, now the psychophysics research suggest that the perceptual learning maybe include the decrease of internal noise and theIn the second part of article, we do some research about the possible neural mechanism of contrast detection learning, based on the single unit recording and animal behavioral research. From the behavioral data, we find that the cats' contrast detection threshold decrease significantly after the training. And the learning effect can transfer partly to the untrained eye, which is also spatial frequency tuned. This result coincides with the previous result about the psychophysics research on human done by Sowden. Then we did the extracellular recording on cat's primary visual cortex, and we find that the training cats' neurons are more sensitivie than normal cats'. We build a CSF model with the signal detection theory and this model can partly explain the learning effect which can transfer partly to the untrained eyes and is spatial frequency tuned. Based on these findings, we conclude that contrast detection learning maybe occur in primary visual cortex.