Tool proprioception at your fingertips - somatosensory representations for tool location
Single Paper Presentation

Daniela Balslev
Neurobiology Research Unit, N9201, Copenhagen University Hospital, Copenhagen and Danish Research Centre for Magnetic Resonance, Hvidovre Hospital, Hvidovre, Denmark

Finn Å. Nielsen
Informatics and Mathematical Modelling, Technical University of Denmark, Lyngby, Denmark

Ian Law
Neurobiology Research Unit, N9201, Copenhagen University Hospital, Copenhagen, Denmark

Olaf B. Paulson
Neurobiology Research Unit, N9201, Copenhagen University Hospital, Copenhagen and Danish Research Center for Magnetic Resonance, Hvidovre Hospital, Hvidovre, Denmark

     Abstract ID Number: 122
     Full text: Not available
     Last modified: May 13, 2003

Abstract
Although the tools we use can extend far away from the body, for instance the edges of a car or the head of a tennis racket, we rarely need to see them in order to tell where they are. This functional magnetic resonance imaging (fMRI) study reports on brain areas that associate tool location with hand proprioception. Eleven healthy subjects watched a cursor move on a computer screen and felt the passive movement of the right index finger on a rectangular mouse field. A condition in which cursor and finger location were congruent, as it is the case during the manipulation of a computer mouse, was compared with a control condition with similar sensory stimulation, but in which cursor and finger locations were randomly associated. There was no significant difference between conditions in duration or speed of finger movement. At several left parietal sites including the hand area in the postcentral gyrus the neural activity was increased in the tool condition compared with the control condition. These areas appear thus to integrate spatially congruent visual and proprioceptive stimuli, suggesting that external objects moving in spatial alignment with the limbs are accommodated into somatic representations.