大脳前頭葉の階層的意思決定機構

Hierarchical Decision-Making Mechanism of the Frontal Lobe

われわれの行動は無意識的な行動から意識的な制御を伴う行動まで多くの階層があり，おのおの異なる神経機構が対応している。大脳前頭葉には多数の皮質運動野が存在し，高度に自動化した運動の遂行から内外の情報に基づく意識的な行動の制御まで役割を分担している。また前頭前野の内側部は行動の決定則自体の選択というより概念的なレベルでの意思決定に関与し，前頭葉内部に階層的な意思決定機構が存在することが明らかになりつつある。

Abstract

Actions performed by humans require various levels of volitional control, ranging from highly practiced, automatic actions to those done in unfamiliar environments which necessitate deliberate controls. The multiple cortical motor areas in the frontal lobe regulate actions that vary in the levels of automaticity vs. intentionality. Further more, a part of the medial prefrontal cortex was found to contribute to the selection of the behavioral tactics, an internal protocol of how to decide what to do, which is a more abstract level of decision making than the selection of action per se. The frontal lobe as a whole functions as a hierarchically organized neural network that regulate both automatic and intentional actions.