Hoffman R E
Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
Acta Psychiatr Scand Suppl. 1999;395:89-94. doi: 10.1111/j.1600-0447.1999.tb05987.x.
The mechanism of hallucinated speech or 'voices', a symptom commonly reported by schizophrenic patients, is poorly understood. We have undertaken two types of study to explore the hypothesis that this symptom arises from pathologically altered speech perception networks. The first consists of neural network computer simulations of narrative speech perception. We have shown that if these networks are partially disconnected or undergo a 'monamine' neuromodulatory disturbance, 'hallucinated speech' (speech percepts occurring in the absence of phonetic input) are simulated as well as specific speech perception impairments. The latter finding prompted us to conduct parallel studies of actual schizophrenic patients using a 'masked speech tracking' (MST) task. MST requires subjects to track narrative speech the phonetic clarity of which is reduced with superimposed multispeaker 'babble.' Hallucinators demonstrated speech perception impairments and experimentally induced perceptual 'illusions' which clearly differentiated them from non-hallucinators and normal controls. Our results support the hypothesis that 'voices' are spurious products of altered speech perception networks.
精神分裂症患者常报告的一种症状——幻听言语或“声音”的机制，目前了解甚少。我们进行了两类研究，以探究这一症状源于言语感知网络发生病理性改变的假说。第一项研究是对叙述性言语感知进行神经网络计算机模拟。我们已经表明，如果这些网络部分断开连接或受到“单胺”神经调节干扰，就会模拟出“幻听言语”（在没有语音输入时出现的言语感知）以及特定的言语感知障碍。后一项发现促使我们使用“掩蔽言语追踪”（MST）任务对实际的精神分裂症患者进行平行研究。MST要求受试者追踪叙述性言语，其语音清晰度会因叠加的多说话者“嘈杂声”而降低。有幻听的患者表现出言语感知障碍以及实验诱导的感知“错觉”，这将他们与无幻听患者和正常对照组明显区分开来。我们的结果支持了“声音”是言语感知网络改变的虚假产物这一假说。
