Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA.
Psychiatry Res. 2013 Sep 30;209(2):142-9. doi: 10.1016/j.psychres.2013.02.034. Epub 2013 May 9.
The aim of the present study was to examine the contributions to decision making (DM) deficits in schizophrenia (SZ) patients of expected value (EV) estimation and loss aversion. Patients diagnosed with SZ (n=46) and healthy controls (n=34) completed two gambling tasks. In one task, participants chose between two options with the same EV across two conditions: Loss frames and Keep frames. A second task involved accepting or rejecting gambles, in which gain and loss amounts varied, determining the EV of each trial. SZ patients showed a reduced "framing effect" relative to controls, as they did not show an increased tendency to gamble when faced with a certain loss. SZ patients also showed a reduced tendency to modify behavior as a function of EV. The degree to which choices tracked EV correlated significantly with several cognitive measures in both patients and controls. SZ patients show distinct deviations from normal behavior under risk when their decisions are based on prospective outcomes. These deviations are two-fold: cognitive deficits prevent value-based DM in more-impaired patients, and in less-impaired patients there is a lack of influence from well-established subjective biases found in healthy people. These abnormalities likely affect everyday DM strategies in schizophrenia patients.
本研究旨在考察预期价值（EV）估计和损失规避对精神分裂症（SZ）患者决策（DM）缺陷的贡献。诊断为 SZ 的患者（n=46）和健康对照组（n=34）完成了两项赌博任务。在一项任务中，参与者在两种条件下选择两种 EV 相同的选项：损失框架和保持框架。第二项任务涉及接受或拒绝赌博，其中收益和损失金额有所不同，确定每次试验的 EV。与对照组相比，SZ 患者表现出降低的“框架效应”，因为当面临一定的损失时，他们没有表现出增加的赌博倾向。SZ 患者还表现出随着 EV 的变化而减少行为改变的趋势。在患者和对照组中，选择与 EV 显著相关的程度与多项认知测量相关。当 SZ 患者的决策基于预期结果时，他们在风险下表现出明显偏离正常行为的情况。这些偏差有两方面：认知缺陷会阻止更严重受损患者的基于价值的 DM，而在受损程度较轻的患者中，缺乏健康人群中存在的既定主观偏见的影响。这些异常可能会影响精神分裂症患者的日常 DM 策略。
