Chee Michael W L, Caplan David
Cognitive Neuroscience Laboratory, Singapore General Hospital.
Neurology. 2002 Dec 24;59(12):1928-34. doi: 10.1212/01.wnl.0000036910.41133.f3.
To document how right hemisphere language dominance in neurologically normal right-handed individuals affects lateralization of face encoding and level of performance in neuropsychological tests.
Three healthy right-handed adults with predominantly right hemisphere language activation during single-word or sentence-level processing were identified from 210 consecutive right-handed subjects studied using blood oxygenation level-dependent contrast fMRI. These three study subjects (S1 to S3) underwent a second scanning session where they performed word and face encoding. Their functional scans were contrasted with those obtained from six healthy control subjects (C1 to C6) with left hemisphere language dominance. Psychometric tests were performed on the study subjects.
Right hemisphere-dominant language activation was reproduced in the second scanning session in the three study subjects. The extent to which the lateralization of face encoding was reversed varied. Right hemisphere language was associated with lower (but within normal) verbal IQ compared with performance IQ in two of three volunteers. Verbal and nonverbal memory scores were normal and did not differ appreciably.
Right hemisphere-dominant language in healthy dextrals exists but is rare. The extent to which face encoding is reversed in these individuals is variable. Cognitive function does not appear to be significantly compromised even though some psychometric test scores are asymmetric in favor of nonverbal performance when the reversal of lateralization of face and word memory is not complete.
记录神经功能正常的右利手个体中右半球语言优势如何影响面部编码的偏侧化以及神经心理测试中的表现水平。
在使用血氧水平依赖对比功能磁共振成像研究的210名连续右利手受试者中，识别出三名在单词或句子水平处理过程中主要激活右半球语言的健康右利手成年人。这三名研究对象（S1至S3）接受了第二次扫描，期间他们进行了单词和面部编码。将他们的功能扫描结果与六名左半球语言优势的健康对照对象（C1至C6）的扫描结果进行对比。对研究对象进行了心理测量测试。
在第二次扫描中，三名研究对象重现了右半球主导的语言激活。面部编码偏侧化逆转的程度各不相同。在三名志愿者中的两名中，与操作智商相比，右半球语言与较低（但在正常范围内）的言语智商相关。言语和非言语记忆分数正常，且没有明显差异。
健康右利手个体中存在右半球主导语言，但很罕见。这些个体中面部编码逆转的程度各不相同。即使当面部和单词记忆的偏侧化逆转不完全时，一些心理测量测试分数偏向非言语表现，但认知功能似乎并未受到明显损害。
