언어인지 뇌과학:입문서

이 지구 상에는 인간을 비롯한 수많은 동물과 식물들이 공존하며 살아가고 있지만, 모두 다 평등한 능력을 갖지는 않는다. 새들에게는 하늘을 자유롭게 날 수 있는 고유한 능력이 갖추어져 있지만, 사자나 호랑이는 그럴 수 없다. 하지만 그들은 다른 동물보다 빨리 달릴 수 있는 능력을 갖고 있다. 그럼, 인간 고유의 능력은 무엇인가? 라는 질문에 대한 대답은 무엇일까? 이 또한 정답이 있는 질문은 아니지만 그중에는 ‘언어’라는 키워드가 포함되리라 믿는다. 다른 종(種)들이 갖지 못한 ‘언어’라는 수단을 이용해 커뮤니케이션 활동을 하는 것은 유일하게 인간에게만 국한된 권리이며 능력이다. 물론 다른 동물에게도 의사소통을 나눌 수 있는 능력이 있음을 보여주는 연구 보고도 있지만, 우리 인간들의 무궁무진한 언어 능력에 비한다면 극히 제한적이다. 이렇게 인간에게 주어진 언어의 본질을 추구하고 실제로 언어 사용을 가능하게 하는 뇌 구조를 관찰하는 학문이 언어 인지 뇌과학이다. 그리고 언어 인지 뇌과학은 ①언어를 지배하는 1400그램의 거대한 우주라 불리는 뇌 구조의 연구를 통해, ②인간의 인지능력(=마음)의 수수께끼를 풀고, ③인류의 행복에 공헌하려는 시도이다. 이 책을 통해서 모든 분들이 평소에 특별한 감정 없이 사용하고 있는 우리 인간들의 위대한 자산인 언어의 심오함을 직접 느끼고 경험해 좀 더 행복한 내일을 맞이하길 바란다.

제1장 언어 인지 뇌과학이란 무엇인가? 1. 인간은 어떻게 언어를 사용할 수 있는가?·····························11 2. 언어 지식 ············································································13 3. 언어 획득 ··········································································· 18 4. 언어 사용 ··········································································· 22 5. 언어의 대뇌 기반 ································································ 24 5.1 언어중추 ········································································24 5.2 실어증············································································26 5.3 뇌 기능 화상법 ································································28 6. 모두의 행복을 위해 ···························································· 32 제2장 언어산출과 언어이해 1. 언어산출과 언어이해의 기능적 의의 ·································· 37 2. 자연언어의 지식과 구조 ···················································· 44 제3장 언어산출과 이해에 관한 심리언어학적 선행 연구 1. 언어 인지 뇌과학 ································································ 53 2. 언어는 마음을 뛰어넘을 수 없다? ···································· 54 2.1 마음의 소리가 입을 통해 전달되기까지의 과정 ··················54 2.2 개념의 추출 난이도는 문형 선택에 어떤 영향을 미치는가? ····60 2.3 같은 구문이 반복적으로 사용되기 쉬운 것은 왜인가? ·········68 3. 언어는 마음의 창? ······························································ 74 3.1 읽고, 듣고, 이해하기까지 어떤 처리 과정을 거치는가? ········75 3.2 문을 이해할 때에는 어떤 정보가 어떤 타이밍에서 사용되는가? ····················································································80 3.3 ‘이동’된 요소는 어떻게 이해되는가? ··································87 4. 앞으로의 전망 ···································································· 93 제 4장 언어산출과 이해의 신경 기반 1. 음성 인식 ··········································································· 99 2. 문자 인식 ··········································································108 3. 어휘 액세스 ······································································· 116 4. 문해석 ···············································································124 5. 문장 이해 ··········································································132 6. 언어산출············································································139 제5장 언어 인지 뇌과학의 연구 사례 - 뒤섞기 어순문의 이해 1. 들어가기 ············································································147 2. 일본어 타동사 문의 두 가지 어순과 통사 구조 ················148 3. fMRI (functional Magnetic Resonance Imaging) 실험 ·········154 3.1 실험 참가자 ···································································154 3.2 실험문···········································································154 3.3 fMRI 실험과제 ·······························································157 3.4 fMRI 데이터 촬영 ··························································160 3.5 fMRI 데이터 분석 ··························································160 4. 결과 ···················································································163 4.1 반응시간과 오답률 ·························································163 4.2 fMRI 데이터 ··································································165 5. 고찰 ···················································································169 5.1 반응시간과 오답률 ·························································169 5.2 좌뇌의 하전두엽(L.IFG) ··················································170 6. 마무리와 앞으로의 과제 ···················································175