抑郁症患者不确定决策过程中奖赏脑区活动强度功能磁共振成像研究

Functional magnetic resonance imaging study on activity intensity of reward brain areas under uncertain decision-making in patients with depression

目的探讨抑郁症患者在不确定(风险、含糊)决策过程中预期价值(expected value,EV)、正预测误差(positive prediction error,+PE)和负预测误差(negative prediction error,-PE)加工时相关脑区活动强度变化。方法2018年7月至2021年2月,收集青岛大学附属医院就诊的抑郁症患者48例(抑郁症组),同期招募青岛大学附属医院健康查体者69例(对照组)。所有受试者在E-Prime系统下完成60%概率获得奖励的风险决策任务和奖损概率未知的含糊决策任务。应用SA-9800脑功能视听觉刺激系统和GE3.0 T功能核磁共振扫描仪对所有受试者进行决策加工时的全脑同步扫描和数据采集,Xjview软件分析相关脑区的激活情况和强度值。采用SPSS 16.0统计软件进行卡方检验、独立样本t检验。结果与对照组比较,抑郁症组在风险决策EV加工时双侧前额叶皮质(prefrontal cortex,PFC)(MNI坐标:左侧x=-45,y=21,z=-6;右侧x=0,y=69,z=-3)、左侧海马旁回(MNI坐标:x=-9,y=0,z=-22)、双侧枕叶(MNI坐标:左侧x=-51,y=-81,z=-3;右侧x=48,y=-84,z=-9)活动强度低(P<0.05),+PE加工时双侧PFC、左侧海马、双侧颞叶、左侧枕中回活动强度低(P<0.05),-PE加工时双侧PFC、右侧壳核、双侧颞叶活动强度低(P<0.05)。与对照组比较,抑郁症组在含糊决策EV加工时双侧PFC、右侧枕叶活动强度低(P<0.05),+PE加工时双侧PFC、右侧壳核、海马、双侧颞叶、双侧枕叶活动强度低(P<0.05),-PE加工时双侧PFC、双侧颞叶活动强度低(P<0.05)。结论抑郁症患者在不确定决策EV、+PE和-PE加工时表现为PFC、边缘系统、枕叶等多个奖赏脑区活动强度降低。

Objective To explore the brain activation intensity changes of depressed patients in the phase of expected value(EV),positive prediction error(+PE)and negative prediction error(-PE)under uncertain(risky,ambiguous)decision-making.Methods From July 2018 to February 2021,a total of 48 depressed patients in the Affiliated Hospital of Qingdao University were collected(depression group),and 69 sex-,age-,and educational level-matched healthy people were recruited as the control group.All participants completed risky and ambiguous decision-making tasks under the E-Prime system.SA-9800 brain functional audio-visual stimulation system and GE3.0 T functional magnetic resonance imaging(fMRI)scanners were used to conduct synchronous scanning and data acquisition.Using Xjview software to analyze the activation intensity of related brain areas to compare the activity intensity of the two groups.SPSS 16.0 software was used for chi square test,independent sample t-test.Results Under risky decision-making,compared with the control group,the brain areas with reduced activation during EV phase in depression group were bilateral prefrontal cortex(PFC)(MNI coordinate:left x=-45,y=21,z=-6;right x=0,y=69,z=-3),left para hippocampal gyrus(PHG)(MNI coordinate:x=-9,y=0,z=-22),bilateral occipital lobe(OL)(MNI coordinate:left x=-51,y=-81,z=-3;right x=48,y=-84,z=-9)(P<0.05).The brain areas with reduced activation during+PE phase were bilateral PFC,left hippocampus(HIP),bilateral temporal lobe(TL),left middle occipital gyrus(P<0.05).The brain areas with reduced activation were bilateral PFC,right putamen,bilateral TL(P<0.05)during-PE phase.Under ambiguous decision-making,compared with the control group,the brain areas with reduced activation during EV phase in depression group were bilateral PFC,right OL(P<0.05);the brain areas with reduced activation during+PE phase were bilateral PFC,right putamen and hippocampus,bilateral TL,bilateral OL(P<0.05);and the brain areas with reduced activation were bilateral PFC,bilateral TL(P<0.05)during-PE phase.Conclusion The study shows that the activities of reward brain areas such as PFC,limbic system and OL system are reduced during EV and PE phase under uncertain decision-making in depressed patients.