Psychology Department, Montclair State University, 1 Normal Ave, Montclair, NJ, 07043, USA.
Department of Psychology, University of South Dakota, 414 E. Clark Street, Vermillion, SD, 57069, USA.
Cogn Res Princ Implic. 2022 Jul 22;7(1):66. doi: 10.1186/s41235-022-00412-7.
The drift diffusion model (DDM) is a widely applied computational model of decision making that allows differentiation between latent cognitive and residual processes. One main assumption of the DDM that has undergone little empirical testing is the level of independence between cognitive and motor responses. If true, widespread incorporation of DDM estimation into applied and clinical settings could ease assessment of whether response disruption occurs due to cognitive or motor slowing. Across two experiments, we manipulated response force (motor speed) and set size to evaluate whether drift rates are independent of motor slowing or if motor slowing impacts the drift rate parameter. The hierarchical Bayesian drift diffusion model was used to quantify parameter estimates of drift rate, boundary separation, and non-decision time. Model comparison revealed changes in set size impacted the drift rate while changes in response force did not impact the drift rate, validating independence between drift rates and motor speed. Convergent validity between parameter estimates and traditional assessments of processing speed and motor function were weak or absent. Widespread application, including neurocognitive assessment where confounded changes in cognitive and motor slowing are pervasive, may provide a more process-pure measurement of information processing speed, leading to advanced disease-symptom management.
漂移扩散模型（DDM）是一种广泛应用于决策的计算模型，它允许区分潜在的认知和剩余过程。DDM 的一个主要假设是认知和运动反应之间的独立性水平，这个假设虽然已经被广泛接受，但很少有实证研究对其进行检验。如果这是正确的，那么将 DDM 估计广泛纳入应用和临床环境中，可以更容易地评估响应中断是由于认知还是运动减速引起的。在两项实验中，我们操纵了反应力（运动速度）和设置大小，以评估漂移率是否独立于运动减速，或者运动减速是否会影响漂移率参数。使用分层贝叶斯漂移扩散模型来量化漂移率、边界分离和非决策时间的参数估计。模型比较表明，设置大小的变化会影响漂移率，而反应力的变化不会影响漂移率，从而验证了漂移率和运动速度之间的独立性。参数估计与传统的处理速度和运动功能评估之间的相关性较弱或不存在。广泛的应用，包括在认知神经评估中，其中认知和运动减速的混杂变化普遍存在，可能会提供更纯粹的信息处理速度的测量，从而实现更先进的疾病症状管理。
