Centre de recherche de l'Institut Universitaire en Santé Mentale de Montréal, 7331 Hochelaga, Montreal, Canada, H1N 3V2; Department of Psychiatry, University de Montréal, 2900 boulevard Édouard-Montpetit, Montreal, Canada, H3T 1J4; Institut Philippe-Pinel de Montréal, 10905 Henri-Bourassa, Montreal, Canada, H1C 1H1.
Centre de recherche de l'Institut Universitaire en Santé Mentale de Montréal, 7331 Hochelaga, Montreal, Canada, H1N 3V2; Department of Psychiatry, University de Montréal, 2900 boulevard Édouard-Montpetit, Montreal, Canada, H3T 1J4.
Psychiatry Res Neuroimaging. 2019 Apr 30;286:45-52. doi: 10.1016/j.pscychresns.2019.03.007. Epub 2019 Mar 14.
Schizophrenia is a severe psychiatric disorder characterized by important cognitive deficits, which ultimately compromise the patients' ability to make optimal decisions. Unfortunately, the neurobiological bases of impaired reward-related decision-making in schizophrenia have rarely been studied. The objective of this study is to examine the neural mechanisms involved in reward-related decision-making in schizophrenia, using functional magnetic resonance imaging (fMRI). Forty-seven schizophrenia patients (DSM-IV criteria) and 23 healthy subjects with no psychiatric disorders were scanned using fMRI while performing the Balloon Analogue Risk Task (BART). A rapid event-related fMRI paradigm was used, separating decision and outcome events. Between-group differences in grey matter volumes were assessed with voxel-based morphometry. During the reward outcomes, increased activations were observed in schizophrenia in the left anterior insula, the putamen, and frontal sub-regions. Reduced grey matter volumes were observed in the left anterior insula in schizophrenia which spatially overlapped with functional alterations. Finally, schizophrenia patients made fewer gains on the BART. The fact that schizophrenia patients had increased activations in sub-cortical regions such as the striatum and insula in response to reward events suggests that the impaired decision-making abilities of these patients are mostly driven by an overvaluation of outcome stimuli.
精神分裂症是一种严重的精神障碍，其特征是存在重要的认知缺陷，最终导致患者无法做出最佳决策。不幸的是，精神分裂症患者在奖励相关决策中受损的神经生物学基础很少被研究。本研究旨在使用功能磁共振成像（fMRI）研究精神分裂症患者中与奖励相关的决策的神经机制。使用 fMRI 对 47 名精神分裂症患者（DSM-IV 标准）和 23 名无精神障碍的健康受试者进行扫描，同时进行气球模拟风险任务（BART）。使用快速事件相关 fMRI 范式分离决策和结果事件。基于体素的形态测量学用于评估灰质体积的组间差异。在奖励结果中，精神分裂症患者在左侧前岛叶、壳核和额叶亚区观察到激活增加。精神分裂症患者的左侧前岛叶灰质体积减少，与功能改变重叠。最后，精神分裂症患者在 BART 中获得的收益较少。精神分裂症患者在奖励事件中出现纹状体和岛叶等皮质下区域的激活增加，这表明这些患者的决策能力受损主要是由于对结果刺激的高估所致。
