title: Posterior Parietal Cortex Drives Inferotemporal Activations During Three-Dimensional Object Vision.
abstract: The primate visual system consists of a ventral stream, specialized for object recognition, and a dorsal visual stream, which is crucial for spatial vision and actions. However, little is known about the interactions and information flow between these two streams. We investigated these interactions within the network processing three-dimensional (3D) object information, comprising both the dorsal and ventral stream. Reversible inactivation of the macaque caudal intraparietal area (CIP) during functional magnetic resonance imaging (fMRI) reduced fMRI activations in posterior parietal cortex in the dorsal stream and, surprisingly, also in the inferotemporal cortex (ITC) in the ventral visual stream. Moreover, CIP inactivation caused a perceptual deficit in a depth-structure categorization task. CIP-microstimulation during fMRI further suggests that CIP projects via posterior parietal areas to the ITC in the ventral stream. To our knowledge, these results provide the first causal evidence for the flow of visual 3D information from the dorsal stream to the ventral stream, and identify CIP as a key area for depth-structure processing. Thus, combining reversible inactivation and electrical microstimulation during fMRI provides a detailed view of the functional interactions between the two visual processing streams.
authors.affiliation: KU Leuven, Laboratorium voor Neuro- en Psychofysiologie, Leuven, Belgium.
authors.forename: Ilse C
authors.initials: IC
authors.lastname: Van Dromme
authors.affiliation: KU Leuven, Laboratorium voor Neuro- en Psychofysiologie, Leuven, Belgium.
authors.forename: Elsie
authors.initials: E
authors.lastname: Premereur
authors.affiliation: KU Leuven, Laboratorium voor Neuro- en Psychofysiologie, Leuven, Belgium.|Department of Neurobiology, University of Chicago, Chicago, Illinois, United States of America.
authors.forename: Bram-Ernst
authors.initials: BE
authors.lastname: Verhoef
authors.affiliation: KU Leuven, Laboratorium voor Neuro- en Psychofysiologie, Leuven, Belgium.|Harvard Medical School, Boston, Massachusetts, United States of America.|MGH Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States of America.
authors.forename: Wim
authors.initials: W
authors.lastname: Vanduffel
authors.affiliation: KU Leuven, Laboratorium voor Neuro- en Psychofysiologie, Leuven, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Janssen
mesh_terms: D006801:Humans; D008279:Magnetic Resonance Imaging; D010296:Parietal Lobe / Q000502:physiology*; D013647:Task Performance and Analysis; D014785:Vision, Ocular