title: Representation of the Numerosity 'zero' in the Parietal Cortex of the Monkey.
abstract: Zero is a fundamental concept in mathematics and modern science. Empty sets are considered a precursor of the concept of numerosity zero and a part of numerical continuum. How is numerosity zero (the absence of visual items) represented in the primate cortex? To address this question, we trained monkeys to perform numerical operations including numerosity zero. Here we show a group of neurons in the posterior parietal cortex of the monkey activated in response to numerosity 'zero'. 'Zero' neurons are classified into exclusive and continuous types; the exclusive type discretely encodes numerical absence and the continuous type encodes numerical absence as a part of a numerical continuum. "Numerosity-zero" neurons enhance behavioral discrimination of not only zero numerosity but also non-zero numerosities. Representation of numerosity zero in the parietal cortex may be a precursor of non-verbal concept of zero in primates.
authors.affiliation: 1] Department of physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan [2] Department of neurosurgery, Southern Tohoku General Hospital, Miyagi 989-2483, Japan.
authors.forename: Sumito
authors.initials: S
authors.lastname: Okuyama
authors.affiliation: Department of physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan.
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Kuki
authors.affiliation: Department of physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Mushiake
mesh_terms: D000818:Animals; D003071:Cognition / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology*; D008251:Macaca; D055641:Mathematical Concepts; D009474:Neurons / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D010775:Photic Stimulation