Reduced model-based decision-making in schizophrenia.
Reduced model-based decision-making in schizophrenia.
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DOI：
10.1037/abn0000164
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发表时间：
2016-08
影响因子：
4.6
通讯作者：
Barch DM
中科院分区：
文献类型：
--
作者：
Culbreth AJ;Westbrook A;Daw ND;Botvinick M;Barch DM
精神分裂症患者利用奖赏历史自适应指导行为的能力减弱。然而，传统上用于评估此类缺陷的任务往往依赖于多个认知和神经过程，导致病因尚未解决。在目前的研究中，我们采用了最新的强化学习的计算形式来区分基于模型的决策和无模型的决策，希望能明确与深圳地区强化学习障碍相关的机制。在这个框架下，决策是无模型的，因为它完全依赖于先前的奖励历史，而如果它依赖于预期信息，如激励状态、未来结果和获得各种结果的可能性，则是基于模型的。对33名精神分裂症患者和30名对照组进行了基于模型和无模型的决策评估，采用了两阶段两种选择的强迫选择任务，以辨别个体对两种形式的强化学习的依赖差异。我们发现，与对照组相比，精神分裂症患者减少了对基于模型的决策的依赖。此外，对基于模型的行为的参数估计与智商和工作记忆测量呈正相关，这表明精神分裂症中出现的基于模型的缺陷可能部分是由更高阶的认知缺陷解释的。这些发现显示了特定的强化学习和决策缺陷，从而为理解精神分裂症的紊乱行为提供了有价值的见解。
Individuals with schizophrenia have a diminished ability to use reward history to adaptively guide behavior. However, tasks traditionally used to assess such deficits often rely on multiple cognitive and neural processes, leaving etiology unresolved. In the current study, we adopted recent computational formalisms of reinforcement learning to distinguish between model-based and model-free decision-making in hopes of specifying mechanisms associated with reinforcement-learning dysfunction in SZ. Under this framework, decision-making is model-free to the extent that it relies solely on prior reward history, and model-based if it relies on prospective information such as motivational state, future consequences, and the likelihood of obtaining various outcomes. Model-based and model-free decision-making was assessed in 33 schizophrenia patients and 30 controls using a 2-stage 2-alternative forced choice task previously demonstrated to discern individual differences in reliance on the two forms of reinforcement-learning. We show that, compared to controls, schizophrenia patients demonstrate decreased reliance on model-based decision-making. Further, parameter estimates of model-based behavior correlate positively with IQ and working memory measures, suggesting that model-based deficits seen in schizophrenia may be partially explained by higher-order cognitive deficits. These findings demonstrate specific reinforcement-learning and decision-making deficits and thereby provide valuable insights for understanding disordered behavior in schizophrenia.