title: Correlated activity supports efficient cortical processing.
abstract: Visual recognition is a computational challenge that is thought to occur via efficient coding. An important concept is sparseness, a measure of coding efficiency. The prevailing view is that sparseness supports efficiency by minimizing redundancy and correlations in spiking populations. Yet, we recently reported that "choristers", neurons that behave more similarly (have correlated stimulus preferences and spontaneous coincident spiking), carry more generalizable object information than uncorrelated neurons ("soloists") in macaque inferior temporal (IT) cortex. The rarity of choristers (as low as 6% of IT neurons) indicates that they were likely missed in previous studies. Here, we report that correlation strength is distinct from sparseness (choristers are not simply broadly tuned neurons), that choristers are located in non-granular output layers, and that correlated activity predicts human visual search efficiency. These counterintuitive results suggest that a redundant correlational structure supports efficient processing and behavior.
authors.affiliation: Department of Neuroscience, Georgetown University Washington, D.C., USA ; Institute of Neuroscience, National Yang-Ming University Taipei, Taiwan.
authors.forename: Chou P
authors.initials: CP
authors.lastname: Hung
authors.affiliation: Department of Neuroscience, Georgetown University Washington, D.C., USA.
authors.forename: Ding
authors.initials: D
authors.lastname: Cui
authors.affiliation: Institute of Neuroscience, National Yang-Ming University Taipei, Taiwan.
authors.forename: Yueh-Peng
authors.initials: YP
authors.lastname: Chen
authors.affiliation: Institute of Neuroscience, National Yang-Ming University Taipei, Taiwan.
authors.forename: Chia-Pei
authors.initials: CP
authors.lastname: Lin
authors.affiliation: Department of Neuroscience, Georgetown University Washington, D.C., USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Levine
keywords: efficient coding; inferior temporal cortex; macaque; object recognition; visual search