title: Spatiotemporal dynamics underlying object completion in human ventral visual cortex.
abstract: Natural vision often involves recognizing objects from partial information. Recognition of objects from parts presents a significant challenge for theories of vision because it requires spatial integration and extrapolation from prior knowledge. Here we recorded intracranial field potentials of 113 visually selective electrodes from epilepsy patients in response to whole and partial objects. Responses along the ventral visual stream, particularly the inferior occipital and fusiform gyri, remained selective despite showing only 9%-25% of the object areas. However, these visually selective signals emerged ∼100 ms later for partial versus whole objects. These processing delays were particularly pronounced in higher visual areas within the ventral stream. This latency difference persisted when controlling for changes in contrast, signal amplitude, and the strength of selectivity. These results argue against a purely feedforward explanation of recognition from partial information, and provide spatiotemporal constraints on theories of object recognition that involve recurrent processing.
authors.affiliation: Program in Biophysics, Harvard University, Boston, MA 02115, USA; Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Hanlin
authors.initials: H
authors.lastname: Tang
authors.affiliation: Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Calin
authors.initials: C
authors.lastname: Buia
authors.affiliation: Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Radhika
authors.initials: R
authors.lastname: Madhavan
authors.affiliation: Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA.
authors.forename: Nathan E
authors.initials: NE
authors.lastname: Crone
authors.affiliation: Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Madsen
authors.affiliation: Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA.
authors.forename: William S
authors.initials: WS
authors.lastname: Anderson
authors.affiliation: Program in Biophysics, Harvard University, Boston, MA 02115, USA; Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Center for Brain Science, Harvard University, Boston, MA 02115, USA. Electronic address: gabriel.kreiman@childrens.harvard.edu.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Kreiman
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002648:Child; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D055815:Young Adult