Different brain correlates for watching real and virtual hand actions.
We investigated whether observation of actions reproduced in three-dimensional virtual reality would engage perceptual and visuomotor brain processes different from those induced by the observation of real hand actions. Participants were asked to passively observe grasping actions of geometrical objects made by a real hand or by hand reconstructions of different quality in 3D virtual reality as well as on a 2D TV screen. We found that only real actions in natural environment activated a visuospatial network including the right posterior parietal cortex. Observation of virtual-reality hand actions engaged prevalent visual perceptual processes within lateral and mesial occipital regions. Thus, only perception of actions in reality maps onto existing action representations, whereas virtual-reality conditions do not access the full motor knowledge available to the central nervous system.
Perani
D
D
Institute of Neuroscience and Bioimaging-CNR, Via Olgettina 60, 20132 Milan, Italy. danielap@mednuc.hsr.it
Fazio
F
F
Borghese
N A
NA
Tettamanti
M
M
Ferrari
S
S
Decety
J
J
Gilardi
M C
MC
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D004292:Dominance, Cerebral / Q000502:physiology; D006225:Hand / Q000502:physiology; D006801:Humans; D009415:Nerve Net / Q000502:physiology; D009778:Occipital Lobe / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D011597:Psychomotor Performance; D013028:Space Perception / Q000502:physiology; D014055:Tomography, Emission-Computed; D014584:User-Computer Interface; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*