title: Object size modulates fronto-parietal activity during reaching movements.
abstract: In both monkeys and humans, reaching-related sensorimotor transformations involve the activation of a wide fronto-parietal network. Recent neurophysiological evidence suggests that some components of this network host not only neurons encoding the direction of arm reaching movements, but also neurons whose involvement is modulated by the intrinsic features of an object (e.g. size and shape). To date, it has yet to be investigated whether a similar modulation is evident in the human reaching-related areas. To fill this gap, we asked participants to reach towards either a small or a large object while kinematic and electroencephalographic signals were recorded. Behavioral results showed that the precision requirements were taken into account and the kinematics of reaching was modulated depending on the object size. Similarly, reaching-related neural activity at the level of the posterior parietal and premotor cortices was modulated by the level of accuracy determined by object size. We therefore conclude that object size is engaged in the neural computations for reach planning and execution, consistent with the results from physiological studies in non-human primates.
authors.affiliation: Dipartimento di Psicologia Generale, Università di Padova, Via Venezia 8, 35131, Padova, Italy.
authors.forename: Vincenza
authors.initials: V
authors.lastname: Tarantino
authors.forename: Teresa
authors.initials: T
authors.lastname: De Sanctis
authors.forename: Elisa
authors.initials: E
authors.lastname: Straulino
authors.forename: Chiara
authors.initials: C
authors.lastname: Begliomini
authors.forename: Umberto
authors.initials: U
authors.lastname: Castiello
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004569:Electroencephalography; D018913:Event-Related Potentials, P300; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D055815:Young Adult
keywords: event-related potentials; human; kinematics; object size; reaching; visuo-motor integration