MIMIC model individual differences

Are Individual Differences Quantitative Or Qualitative? An Integrated Behavioral And Fmri Mimic Approach.
Authors: Jacqueline N. Zadelaar, Wouter D. Weeda, Lourens J. Waldorp, Anna C. K. Van Duijvenvoordee, N. E. Blankenstein, Hilde M. Huizenga

In cognitive neuroscience there is a growing interest in individual differences. We propose the Multiple Indicators Multiple Causes (MIMIC) model of combined behavioral and fMRI data to determine whether such differences are quantitative or qualitative in nature. A simulation study revealed the MIMIC model to have adequate power for this goal, and parameter recovery to be satisfactory. The MIMIC model was illustrated with a re-analysis of Van Duijvenvoorde et al. (2016) and Blankenstein et al. (2018) decision making data. This showed individual differences in Van Duijvenvoorde et al. (2016) to originate in qualitative differences in decision strategies. Parameters indicated some individuals to use an expected value decision strategy, while others used a loss minimizing strategy, distinguished by individual differences in vmPFC activity. Individual differences in Blankenstein et al. (2018) were explained by quantitative differences in risk aversion. Parameters showed that more risk averse individuals preferred safe over risky choices, as predicted by heightened vmPFC activity. We advocate using the MIMIC model to empirically determine, rather than assume, the nature of individual differences in combined behavioral and fMRI datasets.

个体差异的性质是定量还是定性？一种综合行为与fMRI模拟方法。
作者：Jacqueline N. Zadelaar, Wouter D. Weeda, Lourens J. Waldorp, Anna C. K. Van Duijvenvoordee, N. E. Blankenstein, Hilde M. Huizenga

在认知神经科学领域，对个体差异的研究兴趣日益浓厚。本研究提出了一种综合行为与fMRI数据的多种指标多种原因（MIMIC）模型，旨在确定这些差异在本质上是否为定量或定性。模拟研究表明，MIMIC模型具备实现此目标所需的充分效力，且参数恢复情况令人满意。MIMIC模型通过重新分析Van Duijvenvoorde等（2016）及Blankenstein等（2018）的决策数据进行了阐述。结果显示，Van Duijvenvoorde等（2016）的个体差异源于决策策略的定性差异。参数表明，部分个体采用期望值决策策略，而另一些个体则采用损失最小化策略，这些差异可通过个体差异在vmPFC活动中的表现来区分。Blankenstein等（2018）的个体差异则由风险规避的定量差异所解释。参数显示，风险规避程度较高的个体更倾向于选择安全而非冒险，这与vmPFC活动增强的预测相吻合。我们主张利用MIMIC模型来实证地确定，而非假设，综合行为与fMRI数据集中个体差异的性质。