title: The retinotopic organization of macaque occipitotemporal cortex anterior to V4 and caudoventral to the middle temporal (MT) cluster.
abstract: The retinotopic organization of macaque occipitotemporal cortex rostral to area V4 and caudorostral to the recently described middle temporal (MT) cluster of the monkey (Kolster et al., 2009) is not well established. The proposed number of areas within this region varies from one to four, underscoring the ambiguity concerning the functional organization in this region of extrastriate cortex. We used phase-encoded retinotopic functional MRI mapping methods to reveal the functional topography of this cortical domain. Polar-angle maps showed one complete hemifield representation bordering area V4 anteriorly, split into dorsal and ventral counterparts corresponding to the lower and upper visual field quadrants, respectively. The location of this hemifield representation corresponds to area V4A. More rostroventrally, we identified three other complete hemifield representations. Two of these correspond to the dorsal and the ventral posterior inferotemporal areas (PITd and PITv, respectively) as identified in the Felleman and Van Essen (1991) scheme. The third representation has been tentatively named dorsal occipitotemporal area (OTd). Areas V4A, PITd, PITv, and OTd share a central visual field representation, similar to the areas constituting the MT cluster. Furthermore, they vary widely in size and represent the complete contralateral visual field. Functionally, these four areas show little motion sensitivity, unlike those of the MT cluster, and two of them, OTd and PITd, displayed pronounced two-dimensional shape sensitivity. In general, these results suggest that retinotopically organized tissue extends farther into rostral occipitotemporal cortex of the monkey than generally assumed.
authors: Laboratorium voor Neuro- en Psychofysiologie, Biomedische MRI/MoSAIC, KU Leuven Medical School, Campus Gasthuisberg, 3000 Leuven, Belgium, hauke.kolster@med.kuleuven.be wim@nmr.mgh.harvard.edu.
authors: Hauke
authors: H
authors: Kolster
authors: Laboratorium voor Neuro- en Psychofysiologie.
authors: Thomas
authors: T
authors: Janssens
authors: Laboratorium voor Neuro- en Psychofysiologie, Department of Neuroscience, University of Parma Medical School, I-43100, Parma, Italy.
authors: Guy A
authors: http://orcid.org/0000-0002-8179-9584
authors: GA
authors: Orban
authors: Laboratorium voor Neuro- en Psychofysiologie, Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129, and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 hauke.kolster@med.kuleuven.be wim@nmr.mgh.harvard.edu.
authors: Wim
authors: http://orcid.org/0000-0002-9399-343X
authors: W
authors: Vanduffel
mesh_terms: D000818:Animals; D001931:Brain Mapping; D007839:Functional Laterality; D007091:Image Processing, Computer-Assisted; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging; D008297:Male; D008954:Models, Biological; D009039:Motion Perception / Q000502:physiology; D009949:Orientation / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation; D013702:Temporal Lobe / Q000033:anatomy & histology* / Q000502:physiology; D014793:Visual Cortex / Q000033:anatomy & histology* / Q000502:physiology; D014794:Visual Fields; D014795:Visual Pathways / Q000033:anatomy & histology* / Q000502:physiology*
chemical_list: D010100:Oxygen
keywords: extrastriate cortex; function; homology; human; monkey; retinotopy