Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States.
UCB-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, CA, United States.
Sci Rep. 2020 Jun 1;10(1):8881. doi: 10.1038/s41598-020-63962-0.
Auditory working memory impairments feature prominently in schizophrenia. However, the existence of altered and perhaps compensatory neural dynamics, sub-serving auditory working memory, remains largely unexplored. We compared the dynamics of induced high gamma power (iHGP) across cortex in humans during speech-sound working memory in individuals with schizophrenia (SZ) and healthy comparison subjects (HC) using magnetoencephalography (MEG). SZ showed similar task performance to HC while utilizing different brain regions. During encoding of speech sounds, SZ lacked the correlation of iHGP with task performance in posterior superior temporal gyrus (STGp) that was observed in healthy subjects. Instead, SZ recruited the visual word form area (VWFA) during both stimulus encoding and response preparation. Importantly, VWFA activity during encoding correlated with the magnitude of SZ hallucinations, task performance and an independent measure of verbal working memory. These findings suggest that VWFA plasticity is harnessed to compensate for STGp dysfunction in schizophrenia patients with hallucinations.
听觉工作记忆障碍是精神分裂症的一个显著特征。然而，支持听觉工作记忆的神经动力学的改变和可能的代偿作用在很大程度上仍未得到探索。我们使用脑磁图（MEG）比较了精神分裂症患者（SZ）和健康对照组（HC）在言语声音工作记忆期间皮质中诱导的高伽马功率（iHGP）的动力学。SZ 与 HC 具有相似的任务表现，同时利用了不同的大脑区域。在言语声音的编码过程中，SZ 缺乏与健康受试者在后上颞叶（STGp）中 iHGP 与任务表现相关的相关性。相反，SZ 在刺激编码和反应准备期间都招募了视觉单词形式区（VWFA）。重要的是，编码期间的 VWFA 活动与 SZ 幻觉的程度、任务表现和言语工作记忆的独立测量相关。这些发现表明，在有幻觉的精神分裂症患者中，VWFA 的可塑性被用来弥补 STGp 功能障碍。
