title: The neural basis of selection-for-action.
abstract: The selection of objects in the visual environment is important in everyday life when acting in a goal-directed manner. Here we used functional magnetic resonance imaging (fMRI) to investigate brain activity while healthy subjects (N=15) selectively reached to grasp a three-dimensional (3D) target stimulus presented either in isolation or in the presence of 3D non-target stimuli. A pneumatic MRI compatible apparatus was designed to precisely control the presentation of 3D graspable stimuli within the scanner. During scanning subjects were instructed to reach and grasp towards a target presented at an unknown location either in isolation or flanked by two distractor objects. Results indicated that reaching towards and grasping the target object in the presence of other non-target stimuli was associated with greater activation within the contralateral primary motor cortex and the precuneus as compared to the execution of reach-to-grasp movements towards the target presented in isolation. We conclude that the presence of non-targets evokes a differential level of neural activity within areas responsible for the planning and execution of selective reach-to-grasp movement.
authors.affiliation: Howard Florey Institute, Centre for Neuroscience, University of Melbourne, Melbourne, Australia.
authors.forename: Heidi
authors.initials: H
authors.lastname: Chapman
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Pierno
authors.forename: Ross
authors.initials: R
authors.lastname: Cunnington
authors.forename: Maria
authors.initials: M
authors.lastname: Gavrilescu
authors.forename: Gary
authors.initials: G
authors.lastname: Egan
authors.forename: Umberto
authors.initials: U
authors.lastname: Castiello
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping; D003657:Decision Making / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000294:innervation / Q000502:physiology; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology / Q000502:physiology; D009068:Movement / Q000502:physiology*; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*