| ObjectiveTo research the activated brain areas during expected value(EV)and positive and negative prediction error(±PE)progress of uncertainty decision making(risk,ambiguity)and their relationships with behavior strategy in healthy volunteers and depression by using functional magnetic resonance imaging and cognitive neuroscience methods,and to explain the pathogensis of depression from these senses.MethodChapter 1:26 healthy volunteers did 60%-win decision making task and unknown ambiguity task presented by the E-Prime programs,and at the same time,recorded the choose process and profit and losses scores.The stimulus of auditory and vision linked the GE 3.0T magnetic resonance scanner scanned the brains of the subjects when they did tasks.By using the SPM8 and REST software to get the fMRI data analysis,including preprocessing,individual analysis and group analysis,the xjview to present the brain activated regions and the peak intensity and the SPSS17.0 to analyse the behavior data and their relationships with the activated intensity of brain regions.Chapter 2:15 depression patients and 26 healthy volunteers did 60%-win decision making task and unknown ambiguity task presented by the E-Prime programs,and at the same time,recorded the choose process and profit and losses scores.The stimulus of auditory and vision linked the GE 3.0T magnetic resonance scanner scanned the brains of the subjects when they did tasks.By using the SPM8 and REST software to get the fMRI data analysis,including preprocessing,individual analysis,group analysis and comparison between two groups brain activated regions and the peak intensity,the xjview to present the brain activated regions and the peak intensity.To compare the neural activation characteristics under uncertainty reward decision making between healthy volunteers and depression,especially in depressed patients.ResultsChapter 1:Research on the brain activation characteristics of expected value and prediction error in uncertain decision making(1)Risk stay strategy:9.04±2.33,risk shift strategy:2.96±2.33,risk quit strategy:0;ambiguity stay strategy:7.88±2.15,ambiguity shift strategy:2.80±1.61,ambiguity quit strategy:1.32±1.03(2)During expected value phase of risk decesion making,bilateral prefrontal cortex(PFC),right cingulate gyrus,bilateral striatum,left insular,bilateral temporal lobe,left superior parietal lobule,right inferior parietal lobule,left middle occipital gyrus,bilateral posterior lobe of cerebellum were activated(P<0.05).The coding of EV in ambiguity decesion making activated bilateral PFC,right anterior cingulate cortex(ACC),bilateral temporal lobe,left parahippocampus gyrus,left insular,right amygdala,right hippocampus,bilateral inferior parietal lobule,right occipital lobe,right posterior lobe of cerebellum(P<0.05).When computed positive prediction error,bilateral PFC,right putamen,bilateral temporal lobe,bilateral inferior parietal lobule,bilateral posterior lobe of cerebellum were activated in risk decesion making(P<0.05),whereas bilateral PFC,left ACC,bilateral striatum,right insular,bilateral temporal lobe,bilateral inferior parietal lobule,left inferior occipital gyrus and left posterior lobe of cerebellum were activated in ambiguity decesion making(P<0.05).When under negative prediction error context,in risk decesion making,bilateral PFC,right ACC,bilateral insular,bilateral temporal lobe,right inferior parietal lobule,right middle occipital gyrus,left posterior lobe of cerebellum were activated(P<0.05),in ambiguity decesion making,bilateral PFC,right ACC,bilateral insular,left putamen,bilateral temporal lobe,bilateral inferior parietal lobule,bilateral posterior lobe of cerebellum were activated(P<0.05).(3)Correlation analysis showed that in risk decesion making,stay strategy was positively correlated with the activated intensity of left OFC(r=0.57,p<0.01)activated when computed EV,whereas was negatively correlated with that of left insular activated when computed EV(r=-0.63,p<0.01).The stay strategy scores was positively correlated with the activated intensity of right putamen when prediction error is positive(r=0.667,p<0.01),whereas was negatively correlated with that of bilateral insular activated when computed–PE(r左=-0.625,r右=-0.693,p<0.01).Correlation analysis also showed that the behavioral strategy scores have no correlation with the activated intensity of brain regions coding EV in ambiguity decesion making;the stay strategy is positively correlated with the activation intensity of putamen which codes positive prediction error(r=0.684,p<0.01),whereas was negatively correlated with that of bilateral insular activated when computed–PE(r_左=-0.631,r_右=-0.646,p<0.01).There is no other correlativity between behavioral strategy and brain activition intensity was found.Chapter 2:Research on the cerebral activation model of expected value and prediction error in uncertain decesion making in depressive patients(1)Of the depression group,risk stay strategy:6.18±1.33,risk shift strategy:5.72±1.42,risk quit strategy:0;ambiguity stay strategy:4.40±1.43,ambiguity shift strategy:6.00±1.33,ambiguity quit strategy:1.60±1.07;(2)In the risk decesion making,in the depression group,the coding of EV activated bilateral PFC,bilateral cingulate gyrus,bilateral temporal lobe,bilateral inferior parietal lobule,bilateral posterior lobe of cerebellum(p<0.05).When computed positive prediction error,bilateral PFC,right cingulate gyrus,left temporal lobe,bilateral inferior parietal lobule,left posterior lobe of cerebellum in the depression group were activated(P<0.05).When under negative prediction error context,in the depression group,bilateral PFC,right parietal lobe,right occipital lobe,bilateral posterior lobe of cerebellum were activated(P<0.05).In ambiguity decesion making,in the depression group,the coding of EV activated bilateral PFC,bilateral cingulate gyrus,bilateral temporal lobe,bilateral inferior parietal lobule,bilateral posterior lobe of cerebellum(p<0.05).When computed positive prediction error,in the depression group,bilateral PFC,right cingulate gyrus,left temporal lobe,bilateral inferior parietal lobule,left posterior lobe of cerebellum in the control group were activated(P<0.05).When under negative prediction error context,in the depression group,bilateral PFC,right parietal lobe,right occipital lobe,bilateral posterior lobe of cerebellum were activated(P<0.05).(3)Group comparison analyses:in risk decesion making,the coding of EV in depression group activated less in bilateral PFC,left parahippocampus gyrus,bilateral temporal lobe,bilateral occipital lobe,bilateral posterior lobe of cerebellum than in control group(p<0.05),whereas activated less in bilateral PFC,left hippocampus,bilateral temporal lobe,left middle occipital gyrus and bilateral posterior lobe of cerebellum when coded+PE(p<0.05),the coding of-PE in depression group activated less in bilateral PFC,right putamen,bilateral temporal lobe,right inferior parietal lobule and bilateral posterior lobe of cerebellum than in the control group(p<0.05).Group comparison analyses of ambiguity decesion making showed the coding of EV in depression group activated less in bilateral PFC,right temporal lobe,right inferior parietal lobule,right occipital lobe,bilateral posterior lobe of cerebellum than in control group(p<0.05),whereas activated less in bilateral PFC,right putamen and hippocampus,bilateral temporal lobe,bilateral inferior parietal lobule,bilateral occipital lobe and bilateral posterior lobe of cerebellum when coded+PE(p<0.05),The coding of-PE in depression group activated less in bilateral PFC,bilateral temporal lobe,right inferior parietal lobule and left posterior lobe of cerebellum than in the control group(p<0.05).Conclusion1.The expected value of uncertain decesion making is dominated by three kinds of brain functional regions:the putamen reward approach brain regions(Reward,R),the insular loss aversion brain regions(Loss,L)and PFC adjustment brain regions;the positive prediction error processing dominated by the reward approach brain regions;the negative prediction error processing dominated by the loss aversion brain regions;positive and negative prediction error both activate prefrontal cortex which is a brain region adjust reward and loss,the activation intensity in ambiguity processing is higher than in risk processing,which could be called The ALR Model of Brain Uncertain Decision Making.2.The brain activation of expected value and prediction error of the depression patients has changed,the amount of brain areas and intensity of brain activation which code reward approach(Reward,R)decreases,the activation amount and the activation intensity of brain areas which execute adjustment(Adjustment,A)function declines,loss aversion brain regions have no changes,which appear as The weaken ALR model of Brain Decision Making of depression.These differences might be one of reasons of pathogenesis of depression. |
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