Visuo-motor integration and control in the human posterior parietal cortex: evidence from TMS and fMRI.
The posterior parietal cortex is a fundamental structure for visuo-motor integration and control. Here I discuss recent transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) studies that I interpret as suggesting four concepts. The evolutionary process has enlarged the human posterior parietal cortex while still preserving the internal structure of the posterior parietal cortex of other primates. Visuo-motor control in the posterior parietal cortex may be implemented by coding primarily action goals. The lateralization of visuo-motor functions in the posterior parietal cortex suggests that the left posterior parietal cortex is more concerned with tool use and the right posterior parietal cortex is more concerned with imitation of the actions of others. Finally, visuo-motor inter-hemispheric transfer through parietal callosal fibers occurs at the level of 'motor intention'.
Iacoboni
Marco
M
Ahmanson-Lovelace Brain Mapping Center, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, USA. iacoboni@ucla.edu
D001931:Brain Mapping; D006801:Humans; D008279:Magnetic Resonance Imaging; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D050781:Transcranial Magnetic Stimulation; D014795:Visual Pathways / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*