title: What vs. where in touch: an fMRI study.
abstract: Two streams have been identified in cortical visual processing: a ventral stream for form, color, and features, and a dorsal stream for spatial characteristics and motion. We investigated whether similar "what" and "where" dissociations of function exist for human somatosensory processing. Using identical stimuli and hand movements, subjects either performed tactile object recognition (TOR) and ignored location or performed tactile object localization (LOC) and ignored identity. A matched-movement control task separated activation associated with sensorimotor input from higher-level cognitive contributions. Results confirmed separate processing streams for TOR and LOC. TOR activated the frontal pole as well as bilateral inferior parietal and left prefrontal regions involved in tactile feature integration and naming. LOC activated bilateral superior parietal areas involved in spatial processing. The dissociation of object and spatial processing streams appears to be a modality general organizational principle in the brain.
authors.affiliation: Department of Psychology, University of Denver, 2155 S. Race St., Denver, CO 80208, USA. creed@du.edu
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Reed
authors.forename: Roberta L
authors.initials: RL
authors.lastname: Klatzky
authors.forename: Eric
authors.initials: E
authors.lastname: Halgren
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004193:Discrimination Learning / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D012660:Semantics; D013003:Somatosensory Cortex / Q000502:physiology*; D013236:Stereognosis / Q000502:physiology*; D014110:Touch / Q000502:physiology*