Leonhard D, Brugger P
Department of Neurology, University Hospital Zürich, Switzerland.
Neuropsychiatry Neuropsychol Behav Neurol. 1998 Oct;11(4):177-83.
There is a rapidly growing body of evidence for an association between schizophrenic syndromes and the absence of a clear pattern of hemispheric dominance for language. Independent work with healthy subjects suggests that one feature of right hemispheric (RH) linguistic processing is a coarse as opposed to a focused semantic activation. We provide a comprehensive review of the literature to these hitherto unrelated fields of research and present an experiment assessing functional hemispheric asymmetries for language processing in healthy volunteers, differing in the susceptibility to schizophrenia-like experiences and thoughts.
Forty right-handed men were administered a lateralized tachistoscopic lexical decision task. They also completed the Magical Ideation (MI) scale, which examines a variety of paranormal experiences and beliefs.
Although the 20 subjects with MI scores below the median displayed the expected right visual field/left hemisphere (RVF/LH) superiority in lexical decision accuracy, the 20 high scorers were equally proficient in both visual fields. Compared to the low scorers, they made significantly more correct decisions in the left visual field/right hemisphere (LVF/RH).
These results corroborate previous findings of a reduced LH language dominance for subjects scoring high on scales measuring proneness to schizophrenic behavior and thought ("schizotypy"). We propose that this dominance failure, which is commonly observed in patients with acute signs of psychosis, facilitates the emergence of paranormal and delusional ideas by way of RH associative processing characteristics, that is, coarse rather than focused semantic activation. As unfocused semantic processing is also characteristic of creative thinking, the use of the RH semantic system may constitute a selective evolutionary advantage allowing the genes predisposing to schizophrenia to proliferate despite the obvious disadvantages of this devastating disease.
越来越多的证据表明精神分裂症综合征与语言半球优势缺乏明确模式之间存在关联。对健康受试者的独立研究表明，右半球（RH）语言处理的一个特征是语义激活粗糙而非集中。我们对这些迄今为止不相关的研究领域的文献进行了全面综述，并进行了一项实验，评估了健康志愿者在语言处理方面的功能性半球不对称性，这些志愿者在类似精神分裂症的体验和思维易感性方面存在差异。
对40名右利手男性进行了侧化速示器词汇判断任务。他们还完成了神奇观念（MI）量表，该量表考察了各种超自然体验和信念。
虽然20名MI得分低于中位数的受试者在词汇判断准确性上表现出预期的右视野/左半球（RVF/LH）优势，但20名高分者在两个视野中的表现同样出色。与低分者相比，他们在左视野/右半球（LVF/RH）做出的正确决策明显更多。
这些结果证实了先前的发现，即对于在测量精神分裂行为和思维倾向（“精神分裂症型人格”）量表上得分高的受试者，左半球语言优势降低。我们提出，这种优势缺失在急性精神病症状患者中普遍存在，它通过RH联想处理特征，即粗糙而非集中的语义激活，促进了超自然和妄想观念的出现。由于非集中性语义处理也是创造性思维的特征，RH语义系统的使用可能构成一种选择性进化优势，使得尽管精神分裂症这种毁灭性疾病存在明显劣势，但易患精神分裂症的基因仍能增殖。
