身体運動の冗長な運動記憶―脳内表象との関連

Motor Memories Formed by Redundant Neural Representation

身体運動キネマティクスの脳内表象は，多くの研究者が取り組んできながらもまだ解決されていない問題である。しかし，膨大な数の神経細胞を考えれば，ある身体運動の脳内表象はそもそも唯一とは限らず，むしろ冗長性を持ちうる。本稿では，まず，脳内表象と運動記憶との関連を議論する。次に，われわれの研究結果を紹介しながら，脳内表象の冗長性が，文脈に応じて異なる運動記憶を切替えるという運動制御系の性質に反映されうることを示す。

Abstract

Previous studies have tried to elucidate how kinematics of movement is uniquely represented in the brain. Considering the large number of neurons in the brain, however, it is possible that an identical movement is represented by distinct patterns of neural activity in the brain. Here, I first discuss the possible relationship between the neural representation and motor memory. Subsequently, I introduce several experimental examples from my laboratory showing that the redundancy of neural representations of movements might be reflected in the ability of the brain to switch flexibly between distinct motor memories (or internal models) for a physically identical movement depending on different behavioral contexts. I also demonstrate that the ability for forming and retrieving different sets of motor memories plays a functional role in motor control.