Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.
J Int Neuropsychol Soc. 2013 Apr;19(4):410-8. doi: 10.1017/S1355617712001476. Epub 2013 Jan 18.
Reduced left-hemispheric language lateralization has been proposed to be a trait marker for schizophrenia, but the empirical evidence is ambiguous. Recent studies suggest that auditory hallucinations are critical for whether a patient shows reduced language lateralization. Therefore, the aim of the study was to statistically integrate studies investigating language lateralization in schizophrenia patients using dichotic listening. To this end, two meta-analyses were conducted, one comparing schizophrenia patients with healthy controls (n = 1407), the other comparing schizophrenia patients experiencing auditory hallucinations with non-hallucinating controls (n = 407). Schizophrenia patients showed weaker language lateralization than healthy controls but the effect size was small (g = -0.26). When patients with auditory hallucinations were compared to non-hallucinating controls, the effect size was substantially larger (g = -0.45). These effect sizes suggest that reduced language lateralization is a weak trait marker for schizophrenia as such and a strong trait marker for the experience of auditory hallucinations within the schizophrenia population.
左侧语言半球优势减弱被认为是精神分裂症的特征标志物，但实证证据尚存在分歧。最近的研究表明，幻听对于患者是否表现出语言侧化减弱至关重要。因此，本研究的目的是使用双耳分听技术对研究精神分裂症患者语言侧化的研究进行统计整合。为此，进行了两项荟萃分析，一项将精神分裂症患者与健康对照组（n=1407）进行比较，另一项将有幻听的精神分裂症患者与无幻听的对照组（n=407）进行比较。精神分裂症患者的语言侧化弱于健康对照组，但效应量较小（g=-0.26）。当将有幻听的患者与无幻听的对照组进行比较时，效应量明显更大（g=-0.45）。这些效应大小表明，语言侧化减弱作为精神分裂症的特征标志物较弱，而作为精神分裂症患者出现幻听的特征标志物较强。
