@misc{oai:ir.soken.ac.jp:00001198, author = {牧, 陽子 and マキ, ヨウコ and MAKI, Yoko}, month = {2016-02-17, 2016-02-17}, note = {Mirror-symmetrical bimanual movement is more stable than parallel
bimanual movement. This is well established at the kinematic level. I used functional
MRI (fMRI) to evaluate the neural substrates of the stability of mirror-symmetrical
bimanual movement. Right-handed participants (n= 17) rotated disks with their
index fingers bimanually, both in mirror-symmetrical and asymmetrical parallel
modes. I applied the Akaike causality model to both kinematic and fMRI time-series
data. I hypothesized that kinematic stability is represented by the extent of neural
"cross-talk": as the fraction of signals that are common to controlling both hands
increases, the stability also increases. The standard deviation of the phase difference
for the mirror mode was significantly smaller than that for the parallel mode,
confirming that the former was more stable. I used the noise-contribution ratio
(NCR), which was computed using a multivariate autoregressive model with latent
variables, as a direct measure of the cross-talk between both the two hands and the
bilateral primary motor cortices (M ls).The mode-by-direction interaction of the
NCR was significant in both the kinematic and fMRI data. Furthermore, in both sets
of data, the NCR from the right hand to the left was more prominent than vice versa
during the mirror-symmetrical mode, whereas no difference was observed during
parallel movement or rest. The asymmetric interhemispheric interaction from the left
M l to the right M l during symmetric bimanual movement might represent
cortical-level cross-talk, which contributes to the stability of symmetric bimanual
movements., application/pdf, 総研大甲第1205号}, title = {Asymmetric control mechanisms of bimanual coordination: an application of directed connectivity analysis to kinematic and functional MRI data}, year = {} }