Alpha-band desynchronization in human parietal area during reach planning

作者：Fumuro Tomoyuki; Matsuhashi Masao; Miyazaki Tomoko; Inouchi Morito; Hitomi Takefumi; Matsumoto Riki; Takahashi Ryosuke; Fukuyama Hidenao; Ikeda Akio^*

来源：Clinical Neurophysiology, 2015, 126(4): 756-762.

DOI：10.1016/j.clinph.2014.07.026

• Alpha-band desynchronization
• Reaching
• Parietal area
• Motor planning

Objective: The symptoms with optic ataxia suggest that simple and visually guided hand movements are controlled by 2 different neural substrates. To assess the differential frequency-coded posterior parietal cortex (PPC) role in planning visuo-motor goal-directed tasks, we studied the action specificity of event-related desynchronization (ERD) in this area.
Methods: We investigated cortical activity by electroencephalography, while 16 healthy subjects performed self-paced reaching or wrist extension (control) movements. Time-frequency representations were calculated for each movement during the preparatory period.
Results: ERD dynamics in upper alpha-band indicated that preparing a goal-directed action activates contralateral PPC to the moving hand around 1.2 s before starting the movement, while this activation is later (around 0.7 s) in preparing a not-goal-directed action. The posterior dominant rhythm had peak frequency of lower alpha-band at bilateral parietal.
Conclusions: Posterior parietal cortex encodes goal-directed movement preparation through upper alpha-band activity, whereas general attention is processed via lower alpha-band oscillations.
Significance: Preparing to reach an object engages posterior parietal cortex earlier than a not-goal directed movement.

• 出版日期2015-4