Supplementary Material for: Mirroring the Self: Testing Neurophysiological Correlates of Disturbed Self-Experience in Schizophrenia Spectrum

Background: Self-disorders (SDs) have been described as
a core schizophrenia spectrum vulnerability phenotype, both in classic
and contemporary psychopathological literature. However, such a core
phenotype has not yet been investigated adopting a trans-domain approach
that combines the phenomenological and the neurophysiological levels of
analysis. The aim of this study is to investigate the relation between
SDs and subtle, schizophrenia-specific impairments of emotional
resonance that are supposed to reflect abnormalities in the mirror
neurons mechanism. Specifically, we tested whether electromyographic
response to emotional stimuli (i.e. a proxy for subtle changes in facial
mimicry and related motor resonance mechanisms) would predict the
occurrence of anomalous subjective experiences (i.e. SDs). Sampling and Methods:
Eighteen schizophrenia spectrum (SzSp) patients underwent a
comprehensive psychopathological examination and were contextually
tested with a multimodal paradigm, recording facial electromyographic
activity of muscles in response to positive and negative emotional
stimuli. Experiential anomalies were explored with the Bonn Scale for
the Assessment of Basic Symptoms (BSABS) and then condensed into
rational subscales mapping SzSp anomalous self-experiences. Results:
SzSp patients showed an imbalance in emotional motor resonance with a
selective bias toward negative stimuli, as well as a multisensory
integration impairment. Multiple regression analysis showed that
electromyographic facial reactions in response to negative stimuli
presented in auditory modality specifically and strongly correlated with
SD subscore. Conclusions: The study confirms the
potential of SDs as target phenotype for neurobiological research and
encourages research into disturbed motor/emotional resonance as possible
body-level correlate of disturbed subjective experiences in SzSp.

背景：自我紊乱（Self-disorders, SDs）无论在经典还是当代精神病理学文献中，均被界定为精神分裂症谱系核心易感表型。然而，目前尚未有研究采用结合现象学与神经生理学分析维度的跨领域研究方法，对这一核心表型展开探索。本研究旨在探究SDs与精神分裂症特异性的轻微情绪共鸣损伤之间的关联——这类损伤被认为反映了镜像神经元机制的异常。具体而言，我们检验了情绪刺激诱发的肌电反应（即面部模仿及相关运动共鸣机制轻微变化的替代指标）是否能够预测异常主观体验（即SDs）的发生。
采样与方法：18名精神分裂症谱系（schizophrenia spectrum, SzSp）患者接受了全面精神病理学评估，并同步采用多模态实验范式，记录其面对正性与负性情绪刺激时的面部肌电活动。采用波恩基本症状评估量表（Bonn Scale for the Assessment of Basic Symptoms, BSABS）对患者的体验异常进行评估，并将其整合为映射SzSp异常自我体验的合理子量表。
结果：SzSp患者表现出情绪运动共鸣失衡，且对负性刺激存在选择性偏向，同时存在多感觉整合功能损伤。多元回归分析显示，仅针对听觉模态负性刺激诱发的面部肌电反应，与SD得分呈显著强相关。
结论：本研究证实了SDs作为神经生物学研究核心表型的潜力，并推动了将运动/情绪共鸣异常作为SzSp患者主观体验紊乱的躯体层面关联指标的相关研究。