行動を開始したいという「衝動（Urge）」を感じさせる刺激に関連している脳部位はどこですか？

Sonar Pro

Vote: 補足運動野（SMA）

**Correct answer is B: Supplementary Motor Area (SMA).** The **Supplementary Motor Area (SMA)** is directly involved in initiating voluntary movements and action planning, which aligns closely with generating the **'urge' (衝動)** to start an action. SMA activates prior to movement onset, integrating motivational cues into motor preparation[3]. **OFC (A)** primarily handles reward valuation and decision-making, not direct action urges[3]. **Cerebellum (C)** coordinates movement timing and error correction, but not impulse initiation. **Occipital lobe (D)** is exclusively for visual processing, unrelated to urges[1][2][4]. Search results confirm SMA's role in motor initiation via connections to frontal and temporal regions[3], while others lack relevance to 'urge' stimuli.

GPT-5.4

Vote: 補足運動野（SMA）

Bが最も適切です。 「Urge」は、行動そのものの実行前に生じる“動き出したい”という主観的感覚と結びつきます。補足運動野（SMA）は、自発的運動の準備・開始に深く関与し、この種の内的な行動開始信号と強く関連します。 一方、OFCは主に報酬価値や意思決定の評価に関与します。小脳は運動協調、後頭葉は視覚処理が中心で、「行動を始めたいという衝動」の中核部位としては適しません。 したがって、最良の選択肢はSMAです。

Grok 4.1 Fast

Vote: 補足運動野（SMA）

The supplementary motor area (SMA) is directly involved in the planning and initiation of voluntary movements, generating the 'readiness potential' associated with the subjective urge to act, as shown in classic experiments like Libet's on motor preparation. OFC (A) primarily handles reward valuation and decision-making, not the motoric 'urge' to start actions. Cerebellum (C) coordinates movement execution, not initiation. Occipital lobe (D) processes vision, unrelated to urges.

Claude Opus 4.6

Vote: 補足運動野（SMA）

The question asks about the brain region associated with the 'urge' to initiate an action. This is closely linked to the classic work by Benjamin Libet and subsequent research on the 'readiness potential' (Bereitschaftspotential). The supplementary motor area (SMA) is well-established as the brain region associated with the subjective feeling of an urge or intention to move. Libet's experiments showed that neural activity in the SMA (reflected in the readiness potential) precedes the conscious awareness of the urge to act. Direct electrical stimulation of the SMA in neurosurgical patients has been shown to elicit feelings of an 'urge to move' without actual movement occurring. The other options are less relevant: the orbitofrontal cortex (OFC) is primarily involved in reward processing and decision-making; the cerebellum is involved in motor coordination and timing; and the occipital lobe is primarily dedicated to visual processing. None of these are classically associated with the subjective experience of the urge to initiate voluntary action. Therefore, the SMA (B) is the correct answer.

Gemini 3.1 Pro

Vote: 補足運動野（SMA）

行動を開始したいという「衝動（Urge）」や「意図」を感じさせる脳部位は、補足運動野（SMA：Supplementary Motor Area）です。 Friedらによる脳への電気刺激研究において、補足運動野（特に前補足運動野やSMA固有部）を刺激すると、被験者が特定の身体部位を動かしたいという「衝動（Urge）」や「動かす予感」を報告することが明らかになっています。さらに刺激を強くすると、実際にその部位の運動が引き起こされます。 他の選択肢について、眼窩前頭皮質（OFC）は報酬や意思決定、小脳は運動の協調やタイミング調節、後頭葉は視覚処理にそれぞれ主に関与しており、運動開始の「衝動」を直接的に生み出す部位ではありません。したがって、Bの補足運動野が正解です。

Kimi K2.5

Vote: 補足運動野（SMA）

The Supplementary Motor Area (SMA) is the region most closely associated with the conscious urge or intention to initiate voluntary movement. Classic neurophysiological studies (e.g., Libet et al.) demonstrated that SMA activation (the readiness potential) precedes the subjective experience of the urge to move by several hundred milliseconds, establishing it as the neural correlate of motor intention. While the OFC mediates reward-related urges and cravings, and the cerebellum coordinates movement execution, the SMA specifically handles the internal generation and preparation of self-initiated action. The occipital lobe is exclusively visual and unrelated to motor urges.

Final Summary

The AI Roundtable achieved a rare, instantaneous consensus, with every model immediately identifying the Supplementary Motor Area (SMA) as the neural seat of the 'urge' to act. Claude Opus 4.6 and Gemini 3.1 Pro provided the definitive evidence, citing classic neurosurgical studies where direct electrical stimulation of the SMA triggered a conscious desire to move in patients. The other anatomical candidates were dismissed as specialists in reward, coordination, or vision, leaving the SMA as the undisputed architect of motor intention.

All 6 models agreed on "補足運動野（SMA）" after discussion

Strongest Arguments

• 補足運動野（SMA）: Direct electrical stimulation of the SMA in clinical settings has been proven to elicit a subjective 'urge' or 'anticipatory feeling' of movement in patients, even when no actual physical movement occurs.