Observing the touched body magnified alters somatosensory homunculus.
This study aimed to investigate effects of observing the own body being touched on the functional topography of the somatosensory homunculus. We used neuromagnetic source imaging to map the topography in primary somatosensory cortex (SI) while manipulating the visibility of a touched hand. Participants were either able to observe the stimulation in real size or strongly magnified. Results demonstrated a significant shift in SI when participants viewed their stimulated body compared with a rest state or with viewing a neutral object. The magnification of the seen stimulated hand similarly resulted in a shift of the cortical representation zone in SI. We discuss the results as dynamic interactions between vision and touch in SI via back projections from multimodal cortical areas.
Department of Neurology II, Otto-von-Guericke University Magdeburg, Magdeburg, Germany. mischa@neuro2.med.uni-magdeburg.de
Michael
M
Schaefer
Hans-Jochen
HJ
Heinze
Michael
M
Rotte
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006225:Hand / Q000294:innervation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D015225:Magnetoencephalography; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D013003:Somatosensory Cortex / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*