@misc{oai:repo.qst.go.jp:00069177,
 author = {Yamamoto, Kenji and et.al and 山本 憲司},
 month = {Nov},
 note = {It is controversial whether simple-spike activity of cerebellar Purkinje cells during arm movements encodes movement dynamics like muscle activities.  To examine this issue, we trained two monkeys to flex or extend the elbow by 45 deg in 400 ms under resistive and assistive force fields but without altering kinematics. The background color on the CRT screen in front of the monkeys was switched between black and red according to the type of force field so that the monkeys could tell which type of force field would be applied in the upcoming movement. After training, the monkeys instantaneously switched their electromyographic (EMG) activities of biceps and triceps muscles in the first trial when the force field was switched from one to the other. During the task movements, simple-spike discharges were recorded in the intermediate part of the cerebellum in lobules V-VI, and EMG activities were recorded from biceps and triceps muscles. Velocity profiles (kinematics) in the two force fields were almost identical to each other, whereas not only the EMG activities (dynamics) but also simple-spike activities differed significantly depending on the type of force field. In addition, simple-spike activities encoded much larger mutual information with the type of force field than that with the residual small difference in the height of peak velocity. The difference in simple-spike activities averaged over the recorded Purkinje-cells increased ~40 ms before the appearance of the difference in EMG activities between the two force fields, which suggests that the difference of simple-spike activities could be the origin of the difference of muscle activities. We further found that the SS activity switched instantaneously in the first trial when the force field was switched from one to the other, in good agreement with the instantaneous switching of EMG activities. These results show that simple-spike activity of Purkinje cells in the intermediate part of cerebellar lobules V-VI encodes movement dynamics., NEUROSCIENCE 2007},
 title = {Encoding of movement dynamics by Purkinje cell simple spike activity during fast arm movements under resistive assistive and force fields},
 year = {2007}
}