PT  - JOURNAL ARTICLE
AU  - Shlomi Haar
AU  - Opher Donchin
AU  - Ilan Dinstein
TI  - Individual movement variability magnitudes are predicted by cortical neural variability
AID  - 10.1101/097824
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 097824
4099  - http://biorxiv.org/content/early/2017/06/01/097824.short
4100  - http://biorxiv.org/content/early/2017/06/01/097824.full
AB  - Humans exhibit considerable motor variability even across trivial reaching movements. This variability can be separated into specific kinematic components such as extent and direction, which are thought to be governed by distinct neural processes. Here, we report that individual subjects exhibit different magnitudes of kinematic variability, which are consistent (within individual) across movements to different targets and regardless of which arm (right or left) was used to perform the movements. Simultaneous fMRI recordings revealed that the same subjects also exhibited different magnitudes of fMRI variability across movements in a variety of motor system areas. These fMRI variability magnitudes were also consistent across movements to different targets when performed with either arm. Cortical fMRI variability in the posterior-parietal cortex of individual subjects predicted their movement-extent variability. This relationship was apparent only in posterior-parietal cortex and not in other motor system areas, thereby suggesting that individuals with more variable movement preparation exhibit larger kinematic variability. We, therefore, propose that neural and kinematic variability are reliable and interrelated individual characteristics that may predispose individual subjects to exhibit distinct motor capabilities.