新一期Brain杂志网络版刊登了法国研究人员的最新论文"Mentalizing under influence: abnormal dependence on prior expectations in patients with schizophrenia"，科学家认为精神分裂症患者不能正确辨别他人行为意图的原因之一，在于他们不能恰当运用已有经验和刚刚获取的直观信息。
电地铁上，如果一个人从座位上站起来，他是想在下一站下车，还是想给你让座？正常人一般能很快辨别他人行为意图，这也是人们在社会生存的一项基本技能，但精神分裂症患者却没有这种能力。
人们判断他人行为意图的能力主要建立在两种信息的基础上：第一种是通过观察他人动作获取的直观信息；第二种来源于已有的知识和经验。只有借助后者，人们才能理解感觉器官提供的零碎信息。
法国研究人员对阴性和阳性两种精神分裂症患者进行实验，其中阴性症状表现为情感淡漠、主动性缺乏，阳性症状表现为幻觉和妄想。
首先，实验对象观看一些视频片段，在这些片段中，演员们分别带着不同的目的去操作一些物体。为形成先验印象，其中一些片段被多次播放。然后，实验对象重新观看经过删节的相同片段。研究人员通过这种方式控制实验对象能获取的直观信息量，然后让他们猜测演员的意图。
实验结果表明，阴性患者不会利用经验，对他人的意图完全没有任何预期；反之，阳性患者则会过分依赖经验，以至于无视直观信息，他们的想法不会因感官感受到的信息而改变。
精神分裂症患者的这种症状无法通过药物治疗，新研究成果有助于人们探索新的认知疗法，帮助患者更好地运用经验来判断他人的行为意图。此外，这一发现也可用来治疗和阴性精神分裂症类似的自闭症。（生物谷Bioon.com）
doi:10.1093/brain/awr306
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Mentalizing under influence: abnormal dependence on prior expectations in patients with schizophrenia
Valerian Chambon1, Elisabeth Pacherie2,*, Guillaume Barbalat3,4,*, Pierre Jacquet1, Nicolas Franck1,4 and Chl?é Farrer5,6
An impaired ability to appreciate other people's mental states is a well-established and stable cognitive deficit in schizophrenia, which might explain some aspects of patients’ social dysfunction. Yet, despite a wealth of literature on this topic, the basic mechanisms underlying these impairments are still poorly understood, and their links with the clinical dimensions of schizophrenia remain unclear. The present study aimed to investigate the extent to which patients’ impaired ability to appreciate other people's intentions (known as mentalizing) may be accounted for by abnormal interaction between the two types of information that contribute to this ability: (i) the sensory evidence conveyed by movement kinematics; and (ii) the observer's prior expectations. We hypothesized that this is not a generalized impairment, but one confined to certain types of intentions. To test this assumption, we designed four tasks in which participants were required to infer either: (i) basic intentions (i.e. the simple goal of a motor act); (ii) superordinate intentions (i.e. the general goal of a sequence of motor acts); (iii) social basic; or (iv) social superordinate intentions (i.e. simple or general goals achieved within the context of a reciprocal interaction). In each of these tasks, both prior expectations and sensory information were manipulated. We found that patients correctly inferred non-social, basic intentions, but experienced difficulties when inferring non-social superordinate intentions and both basic and superordinate social intentions. These poor performances were associated with two abnormal patterns of interaction between prior expectations and sensory evidence. In the non-social superordinate condition, patients relied heavily on their prior expectations, while disregarding sensory evidence. This pattern of interaction predicted the severity of ‘positive’ symptoms. Social conditions prompted exactly the opposite pattern of interaction: patients exhibited weaker dependence on prior expectations while relying strongly on sensory evidence, and this predicted the severity of ‘negative’ symptoms. We suggest both these patterns can be accounted for by a disturbance in the Bayesian inferential mechanism that integrates sensory evidence (conveyed by movement kinematics) into prior beliefs (about others’ mental states and attitudes) to produce accurate inferences about other people's intentions. on.
