Analysis of activated brain areas in uncertain rewarding processing of decision making on healthy volunteers

Objective To research the activated brain areas of decision making under uncertainty reward processing on healthy volunteers. Method The E-Prime programs were presented 3 kinds of tasks of the decision under uncertain reward processing.15 right-handed healthy volunteers made a response after receiving the task. At the same time, the GE 3.0T magnetic resonance scanner scanned the brains areas of subjects. Individual analysis and group analysis was done with SPM8 software, then the brain activating regions and the peak intensity were gotten. Results Orbitofrontal cortex was activated in certainty, peak intensity 2.4328±0.1949 (P<0.05). Prefrontal cortex, occipital lobe, parietal lobe, posterior lobe of cerebellum, limbic lobe and midbrain were activated under the risk reward processing, peak intensity 2.4228±1.3762 (P<0.05). When under ambiguity reward processing, prefrontal cortex, temporal lobe, occipital lobe, left inferior frontal gyrus and posterior lobe of cerebellum were activated, peak intensity 2.4056±0.4222 (P<0.05). Compared with the task under certainty, posterior lobe of cerebellum, gyri subtemporalis and gyri fusiformis, inferior parietal lobule, anterior central convolution, orbitofrontal cortex, ventrolateral prefrontal cortex, both frontopolar and supramarginal gyrus were activated in task under risk(P<0.05); and both frontopolar were activated in task under ambiguity(P<0.05). Compared with the task under risk, dorsolateral prefrontal cortex and posterior lobe of cerebellum were activated in task under ambiguity(P<0.05). Conclusion There are differences in different types of reward processing of decision making. Key words: Decision making; Uncertain; Reward; Brain; fMRI