title: Contour integration in the primary visual cortex of the opossum.
abstract: To investigate whether contour integration is a generalized mammalian feature we studied single cells in V1 on the South-America opossum ( ), a plesiomorphic animal believed to retain basic characteristics of early mammals. We observed that when a cell's receptive field (RF) was masked (i.e. an artificial scotoma was produced), sweeping a long bar (several times the length of the RF) at the cell's preferred orientation elicited robust responses in many cells (28/103, or 27%). Therefore, some cells in the primary visual cortex of the opossum interpolate under conditions consistent with physical occlusion. The present results indicate that the property of contour integration appears to be a basic property of the mammalian visual system.
authors.affiliation: Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, CCS-BL. G-UFRJ, Ilha do Fundão, Rio de Janeiro, 21949-900, Brazil. ldol@nitnet.com.br
authors.forename: Leticia
authors.initials: L
authors.lastname: Oliveira
authors.forename: Eliane
authors.initials: E
authors.lastname: Volchan
authors.forename: Luiz
authors.initials: L
authors.lastname: Pessoa
authors.forename: Janaina H
authors.initials: JH
authors.lastname: Pantoja
authors.forename: Mateus
authors.initials: M
authors.lastname: Joffily
authors.forename: David
authors.initials: D
authors.lastname: Souza-Neto
authors.forename: Rodrigo F
authors.initials: RF
authors.lastname: Marques
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Rocha-Miranda
mesh_terms: D000818:Animals; D004594:Electrophysiology; D005556:Form Perception / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D009893:Opossums; D009949:Orientation; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology