Sensory-motor mechanisms in human parietal cortex underlie arbitrary visual decisions.
The neural mechanism underlying simple perceptual decision-making in monkeys has been recently conceptualized as an integrative process in which sensory evidence supporting different response options accumulates gradually over time. For example, intraparietal neurons accumulate motion information in favor of a specific oculomotor choice over time. It is unclear, however, whether this mechanism generalizes to more complex decisions that are based on arbitrary stimulus-response associations. In a task requiring arbitrary association of visual stimuli (faces or places) with different actions (eye or hand-pointing movements), we found that activity of effector-specific regions in human posterior parietal cortex reflected the 'strength' of the sensory evidence in favor of the preferred response. These regions did not respond to sensory stimuli per se but integrated sensory evidence toward the decision outcome. We conclude that even arbitrary decisions can be mediated by sensory-motor mechanisms that are completely triggered by contextual stimulus-response associations.
Tosoni
Annalisa
A
Department of Clinical Sciences and Bioimaging, Institute for Advanced Biomedical Technologies, G. d'Annunzio Foundation, Via dei Vestini 31, Chieti 66013, Italy. tosonia@npg.wustl.edu
Galati
Gaspare
G
Romani
Gian Luca
GL
Corbetta
Maurizio
M
D000328:Adult; D001931:Brain Mapping; D003657:Decision Making / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000098:blood supply / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011601:Psychophysics; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology; D012677:Sensation / Q000502:physiology*; D055815:Young Adult
D010100:Oxygen