| Decision making is a higher order cognitive process of human being and the central element of human intelligent activity. Decision making is a process of evaluating and choosing between alternative schemes. Decision making, which exists everywhere and at any time in our life, is an inherent behavior for humans to adjust to the environment, From a simple gambling decision making requiring the choice between big and small bets, to a relatively complex investment decision making, and to the more complex marriage and love decision-making, decision making turns to be more and more important in people's social life. A scientific decision -making not only relates to the living standard of individuals or families, but also influences the operation and management of an enterprise, or even impact a country's development. Therefore, the research on decision making has become the common focus of many disciplines such as economics, management, psychology, cognitive neuroscience and neuro-economics, etc. Simon and Kahneman, two psychologists, won Nobel Economics Prize successively within a rather short time interval, which in itself demonstrates the great importance of the study on decision making. The science on decision making, which integrates theoretical study and practical application as a whole, would become a discipline that contributes directly to social economy constructionIn real life, there are two decision -making situations as usual. One of them is the certain situation where the several schemes are definite, and individuals make decision based on their subjective value assessment, whereas the other is the uncertainty situation, in which several schemes are uncertain, i.e. the objective value or obtaining probability of each scheme is uncertain or both of them are uncertain. Evidently, people are faced with more uncertain decision making situations in real life, .the traditional decision-making studies in uncertain situations, share a common feature, that there exist two or more alternative schemes during the decision -making process and the individuals need to make a choice among them. In real life , another kind of decision -making is prevalent but seldom attracts researchers' attention .This decision making is that the event individuals meet in uncertainty situations requires them to make an acceptance or rejection decision according to their subjective assessment .This research mainly investigates the cognitive and neural mechanism underlying decision makings during the uncertainty situations. Therefore, the present study develops a new research task, entitled acceptance/ rejection gambling task to explore the decision making process in uncertain situations. This research was divided into three parts: Part one includes experiment 1 and 2, which adopts acceptance/ rejection gambling task to examine the cognitive processes and mechanism underlying the decision making under uncertain circumstance. Part two includes experiment 3 and 4, which adopts the fMRI measures to study the neural mechanism underlying the decision making in this uncertain situation. Part three embraces experiment 5, which make an exploratory study on the decision making in this uncertain situation in real life.Part one focuses on the cognitive processes and its mechanism in the uncertain situation. Research Purpose:(l) to examine subjects' confidence assessment process for judgment/decision-making and the relation between confidence subjective probability and objective probability through systematically manipulating the objective probability in uncertain situation; (2)to examine subjects' cognitive mechanism underlying the process of decision-making, with the focus on the relation between confidence subjective probability and decision-making through systematically manipulating the objective probability in uncertain situation. Method: employing confidence assessment task and acceptance /rejection gambling task the present study investigates the confidence assessment and decision-making processes on 101 college student subjects, In order to coincide with the real situation, subjects are paid completely based on their performances during the gambling task. Result; (1) Overall, as confidence increases, the response times have a obvious tendency to decline during the phase of judgment/decision-making and that of assessment. But at the judgment/decision-making stage, the response times were significantly shorter at the first confidence level (50-52%) than those in the second (53-59%) and the third (60-69%) confidence levels. At the assessment phase, the response times at the first confidence level (50-52%) were significantly shorter than those during the second (52-59%), the third (60-69%) and the fourth (70-79%) confidence levels. (2) Overall, subjects' subjective probability of judgment /decision-making confidence increases with the rise of the environmental objective probability. The subjects' subjective probability of judgment /decision-making confidence is significantly higher than environmental objective probability, which shows overconfidence. (3) The response times for subjects' making rejection decision is significantly longer than those during making acceptance decision. (4) Generally speaking, as confidence level rises, the ratio of subjects' making acceptance decision becomes larger, whereas the ratio of subjects' rejection decision declines. In addition, the ratio of making acceptance decision at the first confidence (50-52%) level is higher than that at the second confidence (53-59%). Conclusion: when assessing the environmental objective probability, individuals usually show overconfidence tendency. Of decision-making in this uncertain situation, individuals' confidence about the events' favorable results has a direct influence on decision-making—as confidence level improves, the ratio of individuals' acceptance decision rises, and the latter varies linearly as a function of the former.Part two mainly investigates the neural mechanism underlying the decision making during this uncertain circumstance. Research Purpose:(1)explore the cerebral regions activated under the uncertain condition, and the degree to which cerebral activations fit with the behavioral data.(2)investigate the cerebral regions involved in the assessment of the confidence for the judgment/decision making activity(3)investigate the brain regions sensitive to the confidence evaluation, and the extent to which the cerebral activation data fit with the behavioral data of region of Interest(ROI).Methods: Employing fMRI measures, we carried investigations on 33 right handed undergraduates with respect to the neural mechanism underlying their decision/confidence assessment, and the task was the newly developed acceptance/rejection gambling task and the confidence assessment tasks. Results: the decision making under uncertain circumstances activated numerous brain regions such as left/right precuneus(BA7), left middle frontal gyrus(BA6/9), right middle frontal gyrus(BA9), right inferior parietal lobule(BA40), right inferior temporal gyrus(BA37), left insula(BA13), right cingulate gyrus(BA32).(2)the cerebral regions activated specfic to the rejection decision(rejection minus acceptance) include left inferior frontal gyrus(BA 13/47), right inferior frontal gyrus(BA 13/47), right superior temporal gyrus(BA22), left superior temporal gyrus(BA22), right anterior cingulate guyrus(BA32), and all these activations were positive.(3)at the same voxel within the ROI of left inferior frontal gyrus(BA47) and right anterior cingulate guyrus(BA32),the time-signal strength curve under rejection condition is much higher than that under acceptance condition.(4)judgment/ decision confidence assessment activated several cerebral regions, such as right postcentral gyrus/precentral gyrus(BA2/6), left/right cingulate gyrus(BA24/32), left superior parietal lobule(BA7), right superior parietal lobule(BA7), left inferior frontal gyrus(BA6), left middle frontal gyrus(BA6), right middle frontal gyrus(BA6), right middle occipital gyrus(BA18), left middle occipital gyrus(BA18), left inferior parietal lobule(BA40), right inferior parietal lobule(BA18).(4)within regions of interest, ie, left/right cingulate gyrus(BA24/32),the number of voxels activated increased as the confidence level fell down, and there is a negative linear correlation between them.(5)the number of voxels activated, as well as the time-signal strength curve had a prominent tendency to increase as the confidence level fell down within ROI the left inferior frontal gyrus, and there is a negative linear correlation between them. Conclusion, the decision making under uncertain circumstances activated several cerebral regions, such as left/right precuneus(BA7), left middle frontal gyrus(BA6/9), right middle frontal gyrus(BA9), right inferior parietal lobule(BA40), right inferior temporal gyrus(BA37), left insula(BA13), right cingulate gyrus(BA32).When subtracted by the activations during acceptance condition, the cerebral structures activated specific to the rejection decision includes left inferior frontal gyrus(BA 13/47), right inferior frontal gyrus(BA 13/47), right superior temporal gyrus(BA22), left superior temporal gyrus(BA22), right anterior cingulate guyrus(BA32), and all these activations were positive.The cerebral activation data on cingulate gyrus(BA24/32) and left inferior frontal gyrus(BA47)fit well with the behavioral data, indicating the cerebral activation data is , to some extent a good predictor for the subjects behavioral performances.Part Three is the explorative research on decision-making in the realistic uncertain situations." Research Purpose: (1) To examine the relation between confidence change and the number of negative premises (lost times) in three kinds of life events (important, ordinary, and unimportant). (2) To examine the relation between confidence and decision-making in three kinds of life events. (3) To examine relation between negative premise (lost times) and decision-making in three kinds of life events. Method: to explore the decision-making processes of three kinds of life events among 210 college student subjects. Result: (1) Generally speaking, of three kinds of life events, confidence level declines with the ascent of the number of the negative premises. For important life events, the turning point of THE confidence decline occurs between the third premise and the fourth premises, FOR ordinary life events, the turning point of confidence decline also occurs between the third and the fourth premises. In contrast, for the unimportant life events, the turning point of confidence decline occurs between the second and the third premise. (2)Three kinds of life events have different acceptance threshold, with 51% for the acceptance threshold of important life events, 61% for that of the ordinary life events and 62% for that of the unimportant life events. The important life events are significantly lower with respect to their acceptance threshold than the other two life events, and the acceptance threshold between ordinary and unimportant events showed no significant differences. (3)At important life events, the number of premises critical for the switching of subjects' decision-making is from the fourth to the fifth, where that for the switching of subjects' decision-making at ordinary life events is from the third to the fourth, at unimportant life events. In addition, the number of premises CRITICAL for the switching of decision making is from the second to the third. S=TRUNC (premise /n)+1 model can properly fit the observation data in terms of number of premises necessary for the decision switching during three kinds of life events. Conclusion: of three kinds of life events, negative premises significantly decrease individual's confidence, and the confidence decreases to a certain degree will lead to switch in decision making. Thus, the lowest confidence level is the very acceptance threshold. Three kinds of life events have different acceptance threshold, with 51% for the important life events, 61% for the ordinary life events and 62% for that of the unimportant life events. S=TRUNC (premise/n)+1 model can best fit the observation data with reference to the number of premises necessary for the decision switching during three kinds of life events... |
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