预测误差和期待价值在精神分裂症患者奖赏决策中的应用研究

目的探讨不同严重度阴性症状的精神分裂症(schizophrenia, SZ)患者奖赏决策过程中预测误差和期待价值使用情况。方法纳入稳定期SZ患者80例，其中阴性症状低分组(low-negative symptom, LNS)和阴性症状高分组(high-negative symptom, HNS)各40例。并纳入健康对照(health control, HC)40例。使用汉化的强化学习任务范式，比较代表不同指标的图片的正确率在三组间是否有差异。结果HNS组在赢得奖励条件下的正确率低于HC组，差异具有统计学意义(P=0.04)，而避免损失条件下与HC组相当，差异无统计学意义(P>0.05)。代表期待价值使用的高概率赢钱-高概率避免损失(frequent winners vs frequent loss avoiders, FW-FLA)图片的正确率在三组间差异无统计学意义(F=1.68，P=0.19)。结论阴性症状重的SZ患者在赢得奖励条件不能很好地运用预测误差指导奖赏决策，但在防止损失条件下可以。认知功能相对较好的SZ患者在期待价值使用方面没有明显受损。

Application of prediction error and expected value in reward decision-making in schizophrenia patients

ObjectiveTo investigate the application of prediction error(PE) and expected value(EV) in the reward decision-making process in schizophrenia(SZ) patients with different severity of negative symptoms. MethodsA total of 80 patients with SZ in stable stage and 40 healthy controls(HC) were enrolled in the study. SZ patients were divided into low-negative symptom(LNS) group and high-negative symptom(HNS) group. All participants were asked to finish the Chinese-based Reinforcement Learning Task(RLT). Using the correct rate of picture selection under different conditions of the learning stage to evaluate the subject''s ability to use PE and EV. ResultsThe correct rate of the HNS group was significantly lower than that of the HC group in gain condition(P=0.04), but under the condition of loss avoidance, the differences on correct rate between the HNS group and the HC group were not significant(P>0.05). There was no significant difference between the three groups in the correct rate of frequent winners vs frequent loss avoiders(FW-FLA) used to represent EV(F=1.68, P=0.19). ConclusionSZ patients with severe negative symptoms cannot use PE well to guide reward decision-making under the condition of gain, but they can do under the condition of loss avoidance. Patients with relatively good cognitive function show no significant impairment in application of EV.