title: Preferential encoding of visual categories in parietal cortex compared with prefrontal cortex.
abstract: The ability to recognize the behavioral relevance, or category membership, of sensory stimuli is critical for interpreting the meaning of events in our environment. Neurophysiological studies of visual categorization have found categorical representations of stimuli in prefrontal cortex (PFC), an area that is closely associated with cognitive and executive functions. Recent studies have also identified neuronal category signals in parietal areas that are typically associated with visual-spatial processing. It has been proposed that category-related signals in parietal cortex and other visual areas may result from 'top-down' feedback from PFC. We directly compared neuronal activity in the lateral intraparietal (LIP) area and PFC in monkeys performing a visual motion categorization task. We found that LIP showed stronger, more reliable and shorter latency category signals than PFC. These findings suggest that LIP is strongly involved in visual categorization and argue against the idea that parietal category signals arise as a result of feedback from PFC during this task.
authors.affiliation: Department of Neurobiology, The University of Chicago, Chicago, Illinois, USA.
authors.forename: Sruthi K
authors.initials: SK
authors.lastname: Swaminathan
authors.forename: David J
authors.initials: DJ
authors.lastname: Freedman
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001931:Brain Mapping; D008253:Macaca mulatta; D008297:Male; D010296:Parietal Lobe / Q000166:cytology / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D017397:Prefrontal Cortex / Q000166:cytology / Q000502:physiology*; D012372:ROC Curve; D011984:Sensory Receptor Cells / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology*