Obayashi Choji, Nakashima Taisuke, Onitsuka Toshiaki, Maekawa Toshihiko, Hirano Yoji, Hirano Shogo, Oribe Naoya, Kaneko Kunihiko, Kanba Shigenobu, Tobimatsu Shozo
Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan.
Clin Neurophysiol. 2009 Aug;120(8):1525-33. doi: 10.1016/j.clinph.2009.06.016. Epub 2009 Jul 24.
Schizophrenia impairs early visual cognitive processing. Low and high spatial frequency (LSF, HSF) visual information are differentially processed in humans. We investigated whether electrophysiological abnormalities exist in visual processing for spatial frequency (SF)-filtered neutral/emotional faces in schizophrenics.
Subjects consisted of 16 male chronic schizophrenics and 23 controls. Event-related potentials (ERPs) to SF-filtered (LSF or HSF) and unfiltered (broad SF; BSF) pictures of neutral, happy, and fearful faces were recorded at 20 scalp sites. The relationships between the P100 (P1)/N170 amplitudes and the Global Assessment of Functioning (GAF) scores in patients were also evaluated.
For the P1 amplitudes at O1/O2, controls exhibited a significant LSF>BSF difference, while schizophrenics showed no LSF>BSF difference. For the N170 amplitudes at T5/T6, controls revealed a significant HSF>BSF difference, while schizophrenics showed no such difference. For the P1 latencies, controls but not schizophrenics showed a significant difference (LSF>BSF=HSF). For the N170 latencies, no significant SF differentiation was found between the two groups. For both P1 and N170 amplitudes, no significant effects of facial expressions were observed in controls and patients regardless of SFs. There were significant negative correlations between the GAF scores and the N170 amplitudes to BSF faces in schizophrenics, but not for P1 amplitudes.
Schizophrenics showed abnormal P1 and N170 responses to SF changes in faces, thus indicating decreased SF sensitivities for processing of faces.
Abnormal early visual processing may underlie some of the deficits associated with face recognition in schizophrenia.
精神分裂症会损害早期视觉认知加工。人类对低空间频率（LSF）和高空间频率（HSF）视觉信息的处理方式存在差异。我们研究了精神分裂症患者在对空间频率（SF）滤波后的中性/情绪面孔进行视觉加工时是否存在电生理异常。
研究对象包括16名男性慢性精神分裂症患者和23名对照者。在20个头皮部位记录对SF滤波（LSF或HSF）以及未滤波（宽SF；BSF）的中性、快乐和恐惧面孔图片的事件相关电位（ERP）。还评估了患者中P100（P1）/N170波幅与功能总体评定量表（GAF）评分之间的关系。
在O1/O2部位的P1波幅方面，对照者表现出显著的LSF>BSF差异，而精神分裂症患者未表现出LSF>BSF差异。在T5/T6部位的N170波幅方面，对照者表现出显著的HSF>BSF差异，而精神分裂症患者未表现出此类差异。在P1潜伏期方面，对照者表现出显著差异（LSF>BSF = HSF），而精神分裂症患者未表现出差异。在N170潜伏期方面，两组之间未发现显著的SF差异。对于P1和N170波幅，无论SF如何，对照者和患者中均未观察到面部表情的显著影响。精神分裂症患者的GAF评分与对BSF面孔的N170波幅之间存在显著负相关，但与P1波幅无关。
精神分裂症患者对面孔SF变化表现出异常的P1和N170反应，这表明在面孔加工中SF敏感性降低。
早期视觉加工异常可能是精神分裂症中与面孔识别相关的一些缺陷的基础。
