关键词: 老化, 描述性决策, 经验性决策, 功能性磁共振成像, 单试次分析

Abstract: Decision making can be categorized into description-based and experience-based decision making, depending on whether decision
makers have access to the information of the alternative options. With advanced age, older adults’ cognitive function declines, which may impair their decision-making ability. A previous meta-analysis study showed that the age-related changes on description-based and experience-based decision making was asymmetrical, manifesting as older adults was more vulnerable in experience-based decision making relative to younger counterparts. However, the neural basis underlying this age difference in decision-making category-specific is less understood. In this study, we aimed to examine the age differences in different decision-making tasks (i.e., description-based versus experience-based) combining behavioral and fMRI approaches. We hypothesized that the ability of experience-based decision-making is more susceptible to aging compared to description-based decision making, from evidence of both behavioral and neural aspects. Besides, to examine whether the hyper-activation of brain regions in older adults helps maintain decision-making ability, we performed the single-trial analysis using the logistic mixed-effects model, assuming that the hyper-activation of brain regions in older adults can be benefit for maintaining decision-making ability equaled to young adults.

Twenty-six young adults and 26 older adults completed both description-based and experience-based decision-making tasks in the fMRI scanner, respectively. Description-based decision-making was measured using the risk gambling task. In the experimental condition, the participants needed to choose between a risky option (e.g., 100% gain 10 RMB) and a non-risky option (e.g., 1% gain 1000 RMB or 99% gain 0 RMB). In the control condition, participants were instructed to choose between two equal “100% 0 RMB” options. The probability of participants choosing the non-risky option was used to measure participants' decision-making performance. The experience-based decision making was measured adopting the probability learning task. In the experimental condition, participants were asked to choose between two colored circles that represented as a high value or a low value cue respectively. In the control condition, participants were expected to choose between two same gray circles. The probability of participants choosing high-value options was used to measure participants' decision performance. The order of the two experimental tasks was balanced across participants. To increase involvement, the participants were told that their final reward would be tied to the money they ultimately received in the tasks. The behavioral results herein revealed that the ability of description-based decision making for older adults was relatively reserved, but the agerelated alterations were observed in experience-based decision-making task. Neurally, compared with young adults, older adults exhibited more hyperactivation of decision-related brain regions, regardless of the types of decision tasks. However, this age-related hyper-activation of decision-making regions was asymmetry that was more beneficial for description-based decision making, which might be the potential neural bases of the asymmetry of impaired decision-making ability in the older adults.

This study was the first to combine behavioral and fMRI approaches to explore the age differences in description-based and experience-based decision making. Our results showed that age effect on decision making was task-specific that experience-based decision was more susceptible to aging, which provides direction for decision-making interventions in older adults.