Coarse coding accounts for improvement of spatial discrimination after plastic reorganization in rats and humans
We reported that a protocol of associative (Hebbian) pairing of tactile stimulation (APTS) evokes cortical plastic changes. In rats, we found a selective enlargement of the areas of cortical neurons representing the stimulated skin fields and of the corresponding receptive fields (RFs). Using an analogous APTS protocol in humans revealed an increase of spatial discrimination performance indicating that fast plastic processes based on coactivation patterns act on a cortical and a perceptual level . Here we use the coarse coding scheme as a model for parallel information processing in neural populations to calculate the resolution changes of sensory neurons before and after plastic reorganization. We demonstrate that an increase of RF size that is paralleled by an increase of RF overlap and an enlargement of cortical representational area result in a substantial improvement of sensory resolution which is in the same range as the psychophysically obtained improvement of discrimination in humans.
KeywordsReceptive Field Tactile Stimulation Sensory Space Sensory Resolution Receptive Field Size
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