Perceptual Learning and Brain Reorganization

Science's STKE  08 Jul 2003:
Vol. 2003, Issue 190, pp. tw265-TW265
DOI: 10.1126/stke.2003.190.tw265

In Hebbian learning, two events (classically feeding and the ringing of a bell) become associated with another. Dinse et al. analyzed the cortical changes underlying such perceptual learning by using a lengthy period of fingertip stimulation at randomly assigned intervals of 100 to 3000 ms in human subjects. As expected from previous studies, tactile two-point discrimination was improved after this intense experience on the side that was stimulated but not on the unstimulated side. Improvement was blocked by memantine, an N-methyl-D-aspartate (NMDA)-receptor blocker, and enhanced by the psychostimulant amphetamine, which operates through the increased release of modulatory neurotransmitters. By combining measurements of somatosensory evoked potentials in primary somatosensory cortex with tactile discrimination thresholds, the authors showed a close correlation between the amount of coactivation-induced perceptual improvement and the degree of individual cortical reorganization.

H. R. Dinse, P. Ragert, B. Pleger, P. Schwenkreis, M. Tegenthoff, Pharmacological modulation of perceptual learning and associated cortical reorganization. Science 301, 91-94 (2003). [Abstract] [Full Text]