RT Journal Article
SR Electronic
T1 Neuromagnetic signatures of the spatiotemporal transformation for manual pointing
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 253328
DO 10.1101/253328
A1 Blohm, G.
A1 Alikhanian, H.
A1 Gaetz, W.
A1 Goltz, H.C.
A1 DeSouza, J.F.X.
A1 Cheyne, D.O.
A1 Crawford, J.D.
YR 2018
UL http://biorxiv.org/content/early/2018/08/31/253328.abstract
AB Movement planning involves transforming the sensory goal representation into a command in motor coordinates. Surprisingly, the real-time dynamics of sensorimotor transformations at the whole brain level remain unknown, in part due to the spatiotemporal limitations of fMRI and neurophysiological recordings. Here, we used magnetoencephalography (MEG) during pro-/anti-wrist pointing to determine (1) the cortical areas involved in transforming visual signals into appropriate hand motor commands, and (2) how this transformation occurs in real time, both within and across the regions involved. We computed sensory, motor, and sensorimotor indices in 16 bilateral brain regions for direction coding based on hemispherically lateralized de/synchronization in the α (7-15Hz) and β (15-35Hz) bands. We found a visuomotor progression, from pure sensory codes in ‘early’ occipital-parietal areas, to a temporal transition from sensory to motor coding in the majority of parietal-frontal sensorimotor areas, to a pure motor code, in both the α and β bands. Further, the timing of these transformations revealed a top-down pro/anti cue influence that propagated ‘backwards’ from frontal through posterior cortical areas. These data directly demonstrate a progressive, real-time transformation both within and across the entire occipital-parietal-frontal network that follows specific rules of spatial distribution and temporal order.