類人猿における非対称なブロカの面積
1Division of Psychobiology and Living Links Center, Yerkes Regional Primate Research Center, Emory University, Atlanta, Georgia 30322, USA. lrcbh@rmy.emory.edu
Nature
|December 6, 2001
まとめ
類人猿は,重要な言語領域で人間と脳の不対称性を共有しています. これは,言語の優位性の神経学的根拠が,人類進化より前に存在し,我々の種に特有ではないことを示唆している.
科学分野:
- 神経科学は神経科学である.
- 比較解剖学 比較解剖学とは
- 進化生物学の進化生物学について
背景:
- Brodmannの領域44は,下側前頭回におけるBrocaの領域の一部であり,言語の生産に不可欠である.
- 人間の場合,この領域は左半球の優位性を示しており,これは言語の横行化に関連しています.
- この非対称性の進化的起源を理解することは,言語の進化を理解するための鍵です.
研究 の 目的:
- 人間のブロッドマン領域44で観察された左半球非対称性が他の類人猿種にも存在するかどうかを調査する.
- 言語生産に関連した脳の横行化の進化のタイムラインを探求する.
主な方法:
- チンパンジー (Pan troglodytes),ボノボ (Pan paniscus),ゴリラ (Gorilla gorilla) でのブロッドマン領域44の比較分析. チンパンジー (Pan troglodytes),ボノボ (Pan paniscus),ゴリラ (Gorilla gorilla) でのブロードマン領域44の比較分析. チンパンジー (Pan troglodytes),ボノボ (Pan paniscus),ゴリラ (Gorilla gorilla) での比較分析. チンパンジー (Pan troglodytes),ボノボ (Pan paniscus),ゴリラ (Gorilla gorilla) での比較分析. チンパンジー (Pan troglodytes),ボノボ (Pan paniscus),ゴリラ (Gorilla gorilla) での比較分析. チンパンジー (Gorilla gorilla) での比較分析.
- 研究された種間のこの特定の脳領域における半球の大きさの違いの評価.
主要な成果:
- Brodmann's area 44における同様の左半球の優位性は,調査された3つの類人猿の種すべてで発見されました.
- この解剖学的非対称性は,ヒトで見られるパターンを反映しています.
結論:
- 言語生産における左半球の優位性のための神経解剖学的基底は,少なくとも500万年前に存在していました.
- これらの発見は,このような非対称性はヒト類の進化に特有するものではなく,より深い進化の根源を持っていることを示しています.
関連する概念動画
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01:21Association Areas of the Cortex
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01:10Higher Mental Functions of the Brain: Language
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01:05Cerebral Hemispheres
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01:28Lateralization
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