风险框架情境下决策理性的老化研究

Development and aging of decision-making rationality under risk framework

研究背景由于框架的影响,人们在决策时会表现出一些非理性选择和决策,但随着年龄的增长是否也存在老龄化效应,值得关注。方法以232例年轻人(青年组)和120例老年人(老年组)为被试进行2×2×2完全被试间试验。其中自变量包括决策情境的个体相关性(高相关性、低相关性)、框架价态(正框架、负框架)和年龄段(青年、老年);控制变量为风险概率,作为被试内变量(低概率为33%、高概率为40%),因变量为决策分数。观察风险框架决策情境下之风险决策理性,以及风险寻求倾向的增龄性变化。结果在风险决策框架情境下,老年组被试的非理性决策趋势更强(框架效应),正框架下决策评分为5.13±2.12、负框架下决策评分为6.55±1.05[F(1,118)=21.470,P=0.000;η2=0.156];青年组正框架下决策评分为3.18±2.49、负框架下决策评分为5.00±2.41[F(1,230)=31.260,P=0.000;η2=0.121]。老年组被试更倾向风险选择[F(1,350)=4.820,P=0.029]。结论情境框架发展过程中风险寻求趋势的增加及理性的轻微退行性改变,可以反映老年人眶额叶皮质及腹内侧前额叶皮质、杏仁核功能的老龄化,以及腹内侧前额叶皮质功能的良好维持。此外,老年人对风险概率的理解并未出现退行性改变,但可预示老年人对期望效应值的敏感性下降。

Background Humans often display irrational choice and decision-making due to the frame effect. However, it is unclear whether this irrational choice and decision-making will increase during the aging process. Methods The present research explored development and aging of risky-seeking and rational decision-making with 232 younger adults and 120 older adults. The experiment was a 2 （Age： younger adult and old adult） ~ 2 （Frame： positive and negative） x 2 （Relevance： lower level and higher level）, with the risky probability as a control variable and the decision-making scores as dependent variables. Results The results revealed that older adults demonstrated much more irrational decision- making （framing effect）. In the detail, the risky decision-making score of the older adults in the positive framing was 5.13 ± 2.12, and 6.55 ± 1.05 in the negative framing [F （1,118） = 21.470, P = 0.000; η^2= 0.156], while the risky decision-making score of the younger adults in the positive framing was 3.18 ±2.49, and 5.00 ±2.41 in the negative framing [F （1,230） = 31.260, P = 0.000; η^2= 0.121]. Meanwhile, the older adults showed risk seeking for the life-death scenario [F （1,350） = 4.820, P = 0.029]. Conclusions These results suggested that the hypofunction in orbital and medial prefrontal cortex and amygdale in older adults might be the underlying mechanisms. Furthermore, the susceptibility to expected value （EV） of the older adults might decrease although their scores in risky probability understanding were not significantly different from the younger adults.