Schmack Katharina, Rothkirch Marcus, Priller Josef, Sterzer Philipp
Department of Psychiatry, Charité Universitätsmedizin Berlin, Berlin, 10117, Germany.
Berlin Institute of Health, Berlin, Germany.
Hum Brain Mapp. 2017 Apr;38(4):1767-1779. doi: 10.1002/hbm.23480. Epub 2017 Jan 18.
Positive symptoms of schizophrenia such as delusions and hallucinations are thought to arise from an alteration in predictive mechanisms of the brain. Here, we empirically tested the hypothesis that schizophrenia is associated with an enhanced signalling of higher-level predictions that shape perception into conformity with acquired beliefs. Twenty-one patients with schizophrenia and twenty-eight healthy controls matched for age and gender took part in a functional magnetic resonance imaging (fMRI) experiment that assessed the effect of an experimental manipulation of cognitive beliefs on the perception of an ambiguous visual motion stimulus. At the behavioural level, there was a generally weaker effect of experimentally induced beliefs on perception in schizophrenia patients compared with controls, but a positive correlation between the effect of beliefs on perception and the severity of positive symptoms. At the neural level, belief-related connectivity between a region encoding beliefs in the orbitofrontal cortex (OFC) and a region encoding visual motion in the visual cortex (V5) was higher in patients compared with controls, indicating a stronger impact of cognitive beliefs on visual processing in schizophrenia. We suggest that schizophrenia might be associated with a generally weaker acquisition of externally generated beliefs and a compensatory increase in the effect of beliefs on sensory processing. Our current results are in line with the notion that enhanced signalling of higher-level predictions that shape perception into conformity with acquired beliefs might underlie positive symptoms in schizophrenia. Hum Brain Mapp 38:1767-1779, 2017. © 2017 Wiley Periodicals, Inc.
精神分裂症的阳性症状，如妄想和幻觉，被认为源于大脑预测机制的改变。在此，我们通过实证检验了以下假设：精神分裂症与更高层次预测的信号增强有关，这种预测会使感知与习得的信念保持一致。21名精神分裂症患者和28名年龄及性别匹配的健康对照者参与了一项功能磁共振成像（fMRI）实验，该实验评估了认知信念的实验性操纵对模糊视觉运动刺激感知的影响。在行为层面，与对照组相比，精神分裂症患者中实验诱导的信念对感知的影响通常较弱，但信念对感知的影响与阳性症状的严重程度呈正相关。在神经层面，与对照组相比，患者眶额皮质（OFC）中编码信念的区域与视觉皮质（V5）中编码视觉运动的区域之间与信念相关的连接性更高，这表明精神分裂症中认知信念对视觉处理的影响更强。我们认为，精神分裂症可能与外部产生的信念的普遍较弱习得以及信念对感觉处理的影响的代偿性增加有关。我们目前的结果与以下观点一致：将感知塑造成与习得信念一致的更高层次预测的信号增强可能是精神分裂症阳性症状的基础。《人类大脑图谱》38:1767 - 1779, 2017。© 2017威利期刊公司。
