中国科学院心理健康重点实验室知识库

决策是每个人每天都会进行的活动。二择一时,有人择一而终,有人变换不定。这种个体差异可能与坚持性人格和认知灵活性有关。本研究旨在探讨这种行为特征背后的认知神经机制,以便进一步理解决策变换中存在的个体差异。本研究采用了单变量和多变量体素形态学分析的方法分析了350名大学生(其中女性194人,平均年龄19.97岁)在随机猜牌任务中的换牌频率与大脑灰质体积的相关情况,探讨了坚持性人格特质和认知灵活性与换牌频率的关系,并考察了两者在大脑灰质体积与换牌频率中的中介作用。单变量和多变量体素形态学分析结果都表明,左侧后扣带回、右侧额中回、右侧额极和右侧脑岛区域的灰质体积可以预测被试的换牌频率;坚持性人格和认知灵活性在其中起到了中介作用。这些结果阐释了换牌频率个体差异的认知机制和神经基础,对理解为何有的人一味坚持,而有的人灵活变换背后的原因提供了理论基础,同时为开发改善非理性决策行为的方法提供了重要的参考价值。

Decision making is a common, frequent and important task. It is not uniform though; there are individual differences in decision making processes. One notable differences between decision makers is in repeated binary choice situations. Specifically, when facing repeated binary choices, some people keep choosing the same option while others often switch. Previous research used a random card guessing task to explore the underlying mechanism of such differences in choice strategy. In this task, participants are asked to match a computer-generated “random” choice of a black or red card. The computer does not follow a random choice pattern; it follows a canonical random sequence generated by a Bernoulli process characterized by an equal numbers of black and red choices, switch of color on half of the trials, and streak length following an exponential distribution. In theory, participants should guess cards randomly. Nevertheless, they switch significantly less often than the computer does. In other words, participants present some change resistance and have an increased likelihood to select the same card; this likelihood varies among participants. One notable gap in this research stream pertains to the underlying cognitive and neural mechanism of such card switching behaviors. We partially address this gap in this study. Three hundred and fifty healthy Chinese college students (194 females, mean age = 19.97 years) were recruited for this study. All of them completed the Card Guessing Task, the Temperament and Character Inventory-Revised (TCI-R), and the Wisconsin Card Sorting Test (WCST). One session of high-resolution magnetic resonance anatomical image was also acquired for each individual using a 3T MRI scanner. First, subjects’ frequency of switching, persistence error on the WCST as an index for cognitive flexibility, and persistence dimension score on TCI-R were calculated. Next, the correlation between gray matter volume (GMV) and frequency of switching was tested with both univariate and multivariate voxel-based morphometry (VBM). In addition, the mediation roles of trait persistence and cognitive flexibility in the GMV and switching frequency were tested. Results suggested that the mean frequency of card switching in our sample was 43%, which was significantly lower than 50% (p < 0.001). Importantly, the number varied from 0% to 80%, suggesting large between-individual differences. Correlation analysis showed that both trait persistence and cognitive flexibility negatively correlated with card switching frequency. Univariate VBM analysis showed that (1) the GMV in the Frontal Pole (FP), Posterior Cingulate Gyrus (PCC), Putamen and the left Insular Cortex positively correlated with the card switching frequency, and (2) the GMV in the Medial Temporal Lobe and right Insular Cortex negatively correlated with card switching frequency. Multivariate VBM analysis suggested that the GMV of Posterior Cingulate Gyrus (PCC), Middle Frontal Gyrus (MFG), Insular Cortex, and Frontal Pole could significantly predict individuals’ frequency of card switching. Last, mediation analysis revealed that both trait persistence and cognitive flexibility mediate the relationship between GMV of the implicated regions and card switching frequency. Overall, this study examined individual differences in card switching frequency and the cognitive and neural mechanisms that underlie them. Understanding the reason why some people persist in choosing the same option, while others frequently change their choices is important, and can serve as a basis for understating complex decision making situations that follow a repeated binary choice pattern.