| Autor: |
Rima S; Centre de Recherche Cerveau et Cognition, Université de Toulouse, Toulouse, France. samy.rima@unifr.ch.; Centre National de la Recherche Scientifique, Toulouse Cedex, France. samy.rima@unifr.ch., Cottereau BR; Centre de Recherche Cerveau et Cognition, Université de Toulouse, Toulouse, France.; Centre National de la Recherche Scientifique, Toulouse Cedex, France., Héjja-Brichard Y; Centre de Recherche Cerveau et Cognition, Université de Toulouse, Toulouse, France.; Centre National de la Recherche Scientifique, Toulouse Cedex, France., Trotter Y; Centre de Recherche Cerveau et Cognition, Université de Toulouse, Toulouse, France.; Centre National de la Recherche Scientifique, Toulouse Cedex, France., Durand JB; Centre de Recherche Cerveau et Cognition, Université de Toulouse, Toulouse, France. jbdurand@cnrs.fr.; Centre National de la Recherche Scientifique, Toulouse Cedex, France. jbdurand@cnrs.fr. |
| Abstrakt: |
We investigated the visuotopic organization of macaque posterior parietal cortex (PPC) by combining functional imaging (fMRI) and wide-field retinotopic mapping in two macaque monkeys. Whole brain blood-oxygen-level-dependent (BOLD) signal was recorded while monkeys maintained central fixation during the presentation of large rotating wedges and expending/contracting annulus of a "shaking" fruit basket, designed to maximize the recruitment of PPC neurons. Results of the surface-based population receptive field (pRF) analysis reveal a new cluster of four visuotopic areas at the confluence of the parieto-occipital and intra-parietal sulci, in a location previously defined histologically and anatomically as the posterior intra-parietal (PIP) region. This PIP cluster groups together two recently described areas (CIP1/2) laterally and two newly identified ones (PIP1/2) medially, whose foveal representations merge in the fundus of the intra-parietal sulcus. The cluster shares borders with other visuotopic areas: V3d posteriorly, V3A/DP laterally, V6/V6A medially and LIP anteriorly. Together, these results show that monkey PPC is endowed with a dense set of visuotopic areas, as its human counterpart. The fact that fMRI and wide-field stimulation allows a functional parsing of monkey PPC offers a new framework for studying functional homologies with human PPC. |
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