title: An optimal decision population code that accounts for correlated variability unambiguously predicts a subject's choice.
abstract: Decisions emerge from the concerted activity of neuronal populations distributed across brain circuits. However, the analytical tools best suited to decode decision signals from neuronal populations remain unknown. Here we show that knowledge of correlated variability between pairs of cortical neurons allows perfect decoding of decisions from population firing rates. We recorded pairs of neurons from secondary somatosensory (S2) and premotor (PM) cortices while monkeys reported the presence or absence of a tactile stimulus. We found that while populations of S2 and sensory-like PM neurons are only partially correlated with behavior, those PM neurons active during a delay period preceding the motor report predict unequivocally the animal's decision report. Thus, a population rate code that optimally reveals a subject's perceptual decisions can be implemented just by knowing the correlations of PM neurons representing decision variables.
authors.affiliation: Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Federico
authors.initials: F
authors.lastname: Carnevale
authors.affiliation: Instituto de Neurobiología, Universidad Nacional Autónoma de México, 76230 Querétaro, México.
authors.forename: Victor
authors.initials: V
authors.lastname: de Lafuente
authors.affiliation: Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, 04510 México, DF, México; El Colegio Nacional, 06020 México, DF, México. Electronic address: rromo@ifc.unam.mx.
authors.forename: Ranulfo
authors.initials: R
authors.lastname: Romo
authors.affiliation: Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Néstor
authors.initials: N
authors.lastname: Parga
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D003657:Decision Making / Q000502:physiology*; D008253:Macaca mulatta; D008959:Models, Neurological; D009044:Motor Cortex / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology