title: Reference frames for reaching when decoupling eye and target position in depth and direction.
abstract: Spatial representations in cortical areas involved in reaching movements were traditionally studied in a frontoparallel plane where the two-dimensional target location and the movement direction were the only variables to consider in neural computations. No studies so far have characterized the reference frames for reaching considering both depth and directional signals. Here we recorded from single neurons of the medial posterior parietal area V6A during a reaching task where fixation point and reaching targets were decoupled in direction and depth. We found a prevalent mixed encoding of target position, with eye-centered and spatiotopic representations differently balanced in the same neuron. Depth was stronger in defining the reference frame of eye-centered cells, while direction was stronger in defining that of spatiotopic cells. The predominant presence of various typologies of mixed encoding suggests that depth and direction signals are processed on the basis of flexible coordinate systems to ensure optimal motor response.
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bosco
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Breveglieri
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.|Department of Physiology, Monash University, Clayton, Melbourne, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Hadjidimitrakis
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Galletti
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Fattori
mesh_terms: D000200:Action Potentials; D000818:Animals; D003867:Depth Perception; D005133:Eye Movements / Q000502:physiology; D005403:Fixation, Ocular / Q000502:physiology; D008252:Macaca fascicularis; D008297:Male; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*