Ohara Naotoshi, Hirano Yoji, Oribe Naoya, Tamura Shunsuke, Nakamura Itta, Hirano Shogo, Tsuchimoto Rikako, Ueno Takefumi, Togao Osamu, Hiwatashi Akio, Nakao Tomohiro, Onitsuka Toshiaki
Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Medical Corporation Seiryokai, Mimamigaoka Hospital, Fukuoka, Japan.
Front Psychiatry. 2020 Sep 3;11:554844. doi: 10.3389/fpsyt.2020.554844. eCollection 2020.
Neuropsychological studies have revealed that patients with schizophrenia (SZ) have facial recognition difficulties and a reduced visual evoked N170 response to human faces. However, detailed neurophysiological evidence of this face processing deficit in SZ with a higher spatial resolution has yet to be acquired. In this study, we recorded visual evoked magnetoencephalography (MEG) and examined whether M170 (a magnetic counterpart of the N170) activity deficits are specific to faces in patients with chronic SZ.
Participants were 26 patients with SZ and 26 healthy controls (HC). The M170 responses to faces and cars were recorded from whole-head MEG, and global field power over each temporal cortex was analyzed. The distributed M170 sources were also localized using a minimum-norm estimation (MNE) method. Correlational analyses between M170 responses and demographics/symptoms were performed.
As expected, the M170 was significantly smaller in the SZ compared with the HC group in response to faces, but not to cars (faces: p = 0.01; cars: p = 0.55). The MNE analysis demonstrated that while the M170 was localized over the fusiform face area (FFA) in the HC group, visual-related brain regions other than the FFA were strongly activated in the SZ group in both stimulus conditions. The severity of negative symptoms was negatively correlated with M170 power (rho = -0.47, p = 0.01) in SZ. Within HC, there was a significant correlation between age and the M170 responses to faces averaged for both hemispheres (rho = 0.60, p = 0.001), while such a relationship was not observed in patients with SZ (rho = 0.09, p = 0.67).
The present study showed specific reductions in the M170 response to human faces in patients with SZ. Our findings could suggest that SZ is characterized by face processing deficits that are associated with the severity of negative symptoms. Thus, we suggest that social cognition impairments in SZ might, at least in part, be caused by this functional face processing deficit.
神经心理学研究表明，精神分裂症（SZ）患者存在面部识别困难，且对人脸的视觉诱发电位N170反应降低。然而，尚未获得具有更高空间分辨率的关于SZ患者这种面部处理缺陷的详细神经生理学证据。在本研究中，我们记录了视觉诱发脑磁图（MEG），并检查了M170（N170的磁对应物）活动缺陷是否在慢性SZ患者中对面孔具有特异性。
参与者为26例SZ患者和26名健康对照者（HC）。从全脑MEG记录对面孔和汽车的M170反应，并分析每个颞叶皮质的全局场功率。还使用最小范数估计（MNE）方法对分布式M170源进行定位。进行了M170反应与人口统计学/症状之间的相关性分析。
正如预期的那样，与HC组相比，SZ组对面孔的M170明显较小，但对汽车则不然（面孔：p = 0.01；汽车：p = 0.55）。MNE分析表明，虽然HC组的M170定位于梭状面孔区（FFA），但在两种刺激条件下，SZ组中除FFA外的与视觉相关的脑区均被强烈激活。在SZ中，阴性症状的严重程度与M170功率呈负相关（rho = -0.47，p = 0.01）。在HC中，年龄与两个半球平均对面孔的M170反应之间存在显著相关性（rho = 0.60，p = 0.001），而在SZ患者中未观察到这种关系（rho = 0.09，p = 0.67）。
本研究表明SZ患者对人脸的M170反应有特异性降低。我们的研究结果可能表明，SZ的特征是与阴性症状严重程度相关的面部处理缺陷。因此，我们认为SZ中的社会认知障碍可能至少部分是由这种功能性面部处理缺陷引起的。
