Neural representation of complex spatial patterns in peripheral afferents and somatosensory cortex of the awake monkey

Abstract

The human capacity for tactual, spatial pattern recognition has been investigated by a number of people using embossed letters and Braille characters and the Optacon. The experiments reported here use identical stimuli in neurophysiological experiments to study the neural mechanisms underlying this spatial pattern recognition. The approach is to reconstruct the spatiotemporal patterns of neural activity evoked by these stimuli in the periphery and the cortex. The aim is to determine which pathways convey the critical information underlying pattern recognition and to analyze the transformations as the information proceeds centrally. The results of these experiments are “neural images” which we believe represent the distributed patterns of neural activity as the brain sees them. As expected, these images are mildly distorted replicas of the initial stimuli at the level of the periphery, i.e., the letter A evokes distributed patterns of neural activity in the form of an A. At the level of the cortex the “neu...