title: Interactions within the hand representation in primary somatosensory cortex of primates.
abstract: Previous studies indicate that primary somatosensory cortical area 3b in macaques contains a somatotopic map of the hand, encompassing representations of each digit. However, numerous observations including recent findings in anesthetized New World monkeys indicate that that the digit representations within the map are not discrete. We assessed the generality and spatial extent of these effects in awake macaques. We show that, within a given digit representation, (1) there is response to stimulation of all other digits tested, extending across most or all of the digit map, and (2) response to stimulation of the locally preferred digit is modulated by concurrent stimulation of each of the other digits. Control experiments rule out effects of attention and mechanical spread of stimulation. We thus confirm that, even at the first level of somatosensory cortical processing, inputs from potentially all of the digits frame the context within which the input to a single digit is represented.
authors.affiliation: The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA. michael.lipton@einstein.yu.edu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Lipton
authors.forename: Mark C
authors.initials: MC
authors.lastname: Liszewski
authors.forename: M Noelle
authors.initials: MN
authors.lastname: O'Connell
authors.forename: Aimee
authors.initials: A
authors.lastname: Mills
authors.forename: John F
authors.initials: JF
authors.lastname: Smiley
authors.forename: Craig A
authors.initials: CA
authors.lastname: Branch
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Isler
authors.forename: Charles E
authors.initials: CE
authors.lastname: Schroeder
mesh_terms: D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006225:Hand / Q000502:physiology*; D008253:Macaca mulatta; D010812:Physical Stimulation / Q000379:methods; D013003:Somatosensory Cortex / Q000502:physiology*