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Somatosensory Discrimination of Shape: Tactile Exploration and Cerebral Activation
Author(s) -
Seitz Rüdiger J.,
Roland Per E.,
Bohm Christian,
Greitz Torgny,
StoneElander Sharon
Publication year - 1991
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.1991.tb00835.x
Subject(s) - somatosensory system , secondary somatosensory cortex , neuroscience , psychology , posterior parietal cortex , index finger , premotor cortex , supplementary motor area , cerebral blood flow , postcentral gyrus , sensory system , sensory stimulation therapy , anatomy , medicine , functional magnetic resonance imaging , dorsum , cardiology
This study of somatosensory discrimination of rectangular parallelepipeds with the right hand had three purposes: (i) to describe the exploratory finger movements; (ii) to reveal the anatomical brain structures specifically engaged in the production of exploratory finger movements; and (iii) to reveal the anatomical structures specifically engaged in the discrimination of tactually sensed shape. The thumb was the most active finger, moving with a mean exploration frequency of 2.4 Hz, as evident from videotape records of the exploratory finger movements. The cerebral structures activated during somatosensory discrimination were mapped by measurements of regional cerebral blood flow (rCBF) in six healthy male volunteers with positron emission tomography (PET) and the use of the computerized brain atlas of Greitz et al. (1991, J. Comp. Ass. Tomogr. , 15, 26–38). The rCBF changes caused by somatosensory discrimination were compared point‐to‐point to a PET‐study on right‐hand finger movements and a PET‐study on vibration stimulation of the right hand. From these results the following conclusions were drawn. The rCBF increase in the left superior parietal lobule indicated the site engaged in the analysis of shape. The rCBF increases in the left supplementary sensory area, bilaterally in premotor areas, in the left putamen, the right dentate nucleus and bilaterally in the posterior cerebellum were related to the control of the tactile exploratory finger movements. The rCBF increases in the right homologue of Broca's area, bilaterally in the superior prefrontal cortex and in the right midfrontal cortex probably resulted from working memory, the direction of attention, and the discrimination process.