Mechanisms of audio-motor integration during keyboard instrument playing

MIDIキーボードと機能的磁気共鳴画像法(fMRI)を用い，聴覚フィードバックによって指先の力を調整するときの脳活動を検討した．本研究は，指の力のコントロールにおける聴覚フィードバックの効果と，その時の脳活動について明らかにすることを目的として行った．実験の結果，指先の力を制御する際に音圧と力が対応する聴覚フィードバックが返ってくる場合(Normal条件)の方が，対応していない場合(Reverse条件)よりうまく指先を制御できることが示された．また，力の補正に関わると考えられる脳活動が左角回と右上頭頂小葉で確認された．さらに，左背側前運動皮質や両側の一次聴覚皮質が聴覚フィードバックの音の違いにそれぞれ特異的な応答を示すことが示唆された．この研究は，聴覚と運動の統合メカニズムについて議論する一助となることが期待される．
We conducted an experiment using a keyboard instrument. The purpose of this study was to reveal what kind of auditory feedback is helpful for controlling finger force. Participans were asked to control the force of fingertips depending on auditory feedback, and the brain activities related to the force control were measured with functional magnetic resonance imaging. As a result, it was shown that "Normal condition," in which the intensity of feedback sound increased as the finger force was strengthened, is more effective in controlling the fingertip force than "Reverse condition." Furthermore, we found brain activity associated with adjustment of force control in the left angular gyrus and right superior parietal lobule. In addition, we observed activation patterns specific to feedback sound in the left dorsal premotor cortex and bilateral primary auditory cortex. This study will give an insight into adaptive mechanisms of auditory-motor integration.