title: Region-Specific Summation Patterns Inform the Role of Cortical Areas in Selecting Motor Plans.
abstract: Given an instruction regarding which effector to move and what location to move to, simply adding the effector and spatial signals together will not lead to movement selection. For this, a nonlinearity is required. Thresholds, for example, can be used to select a particular response and reject others. Here we consider another useful nonlinearity, a supralinear multiplicative interaction. To help select a motor plan, spatial and effector signals could multiply and thereby amplify each other. Such an amplification could constitute one step within a distributed network involved in response selection, effectively boosting one response while suppressing others. We therefore asked whether effector and spatial signals sum supralinearly for planning eye versus arm movements from the parietal reach region (PRR), the lateral intraparietal area (LIP), the frontal eye field (FEF), and a portion of area 5 (A5) lying just anterior to PRR. Unlike LIP neurons, PRR, FEF, and, to a lesser extent, A5 neurons show a supralinear interaction. Our results suggest that selecting visually guided eye versus arm movements is likely to be mediated by PRR and FEF but not LIP.
authors.affiliation: Department of Psychology, Yale University, New Haven, CT 06511, USA Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06520, USA.
authors.forename: Steve W C
authors.initials: SW
authors.lastname: Chang
authors.affiliation: Department of Psychology, Sacramento State University, Sacramento, CA 95819, USA.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Calton
authors.affiliation: Department of Psychology, New York University, New York, NY 10003, USA.
authors.forename: Bonnie M
authors.initials: BM
authors.lastname: Lawrence
authors.affiliation: Department of Anatomy and Neurobiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA.
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Dickinson
authors.affiliation: Department of Anatomy and Neurobiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA.
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Snyder
mesh_terms: D000818:Animals; D001132:Arm / Q000502:physiology; D005625:Frontal Lobe / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D009043:Motor Activity; D009044:Motor Cortex / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology; D011597:Psychomotor Performance; D012438:Saccades
keywords: frontal eye field; lateral intraparietal area; motor decision; motor planning; parietal reach region