Coherence potentials encode simple human sensorimotor behavior.
Recent work has shown that large amplitude negative periods in the local field potential (nLFPs) are able to spread in saltatory manner across large distances in the cortex without distortion in their temporal structure forming 'coherence potentials'. Here we analysed subdural electrocorticographic (ECoG) signals recorded at 59 sites in the sensorimotor cortex in the left hemisphere of a human subject performing a simple visuomotor task (fist clenching and foot dorsiflexion) to understand how coherence potentials arising in the recordings relate to sensorimotor behavior. In all behaviors we found a particular coherence potential (i.e. a cascade of a particular nLFP wave pattern) arose consistently across all trials with temporal specificity. During contrateral fist clenching, but not the foot dorsiflexion or ipsilateral fist clenching, the coherence potential most frequently originated in the hand representation area in the somatosensory cortex during the anticipation and planning periods of the trial, moving to other regions during the actual motor behavior. While these 'expert' sites participated more consistently, other sites participated only a small fraction of the time. Furthermore, the timing of the coherence potential at the hand representation area after onset of the cue predicted the timing of motor behavior. We present the hypothesis that coherence potentials encode information relevant for behavior and are generated by the 'expert' sites that subsequently broadcast to other sites as a means of 'sharing knowledge'.
National Centre for Biological Sciences, TIFR, Bangalore, India.
Dhanya
D
Parameshwaran
Nathan E
NE
Crone
Tara C
TC
Thiagarajan
D000328:Adult; D001519:Behavior / Q000502:physiology; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005528:Foot; D006225:Hand; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*