Background and Hypothesis Hallucinations may be driven by an excessive influence of prior expectations on current experience. Initial work has supported that contention and implicated the anterior insula in the weighting of prior beliefs. Study Design Here we induce hallucinated tones by associating tones with the presentation of a visual cue. We find that people with schizophrenia who hear voices are more prone to the effect and using computational modeling we show they overweight their prior beliefs. In the same participants, we also measured glutamate levels in anterior insula, anterior cingulate, dorsolateral prefrontal, and auditory cortices, using magnetic resonance spectroscopy. Study Results We found a negative relationship between prior-overweighting and glutamate levels in the insula that was not present for any of the other voxels or parameters. Conclusions Through computational psychiatry, we bridge a pathophysiological theory of psychosis (glutamate hypofunction) with a cognitive model of hallucinations (prior-overweighting) with implications for the development of new treatments for hallucinations.

中文翻译：

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通过 1H-MR 波谱法关联谷氨酸盐、条件性幻觉和临床幻觉

背景和假设 幻觉可能是由先前的期望对当前经验的过度影响所驱动的。初步工作支持该论点，并暗示前脑岛在先前信念的权重中。研究设计 在这里，我们通过将音调与视觉提示的呈现相关联来诱发幻觉音调。我们发现听到声音的精神分裂症患者更容易受到这种影响，并且我们使用计算模型表明他们过度重视他们先前的信念。在同一参与者中，我们还使用磁共振波谱测量了前脑岛、前扣带回、背外侧前额叶和听觉皮层中的谷氨酸水平。研究结果 我们发现先前超重和脑岛谷氨酸水平之间存在负相关关系，而其他任何体素或参数都不存在这种关系。结论 通过计算精神病学，我们将精神病的病理生理学理论（谷氨酸功能减退）与幻觉的认知模型（先前超重）联系起来，这对开发新的幻觉治疗方法具有重要意义。