抑郁症患者时距复制任务中的表现及其认知机制

Performance and Cognitive Mechanisms in the Time Reproduction Task in Patients with Depression

目的:采用时间复制任务探讨抑郁症患者时距知觉表现及工作记忆和注意网络在其中的作用机制。方法:研究采用2(组别:抑郁症组、正常组)×5(标准时距:700ms、1700ms、2700ms、3700ms、4700ms)的混合实验设计,其中组别为被试间变量,标准时距为被试内变量。因变量指标为相对误差和变异系数。同时采用N-back任务测量工作记忆,测量指标为反应时和正确率;采用注意网络范式测量注意功能,测量指标为反应时。结果:相对于正常组,抑郁症组在700ms和1700ms上相对误差显著大于1,在4700ms上相对误差显著小于1;复制700ms、1700ms、2700ms、3700ms及4700ms的变异系数均显著更大;抑郁症组在执行控制网络上的反应时显著更长;进一步中介分析发现执行控制网络的反应时在组别与1700ms、2700ms、3700ms和4700ms时距的复制变异系数之间无中介作用,2-back任务的正确率在组别与1700ms、2700ms、3700ms和4700ms时距的复制变异系数之间起中介作用。结论:抑郁症患者存在更加高估短时距和低估长时距的趋势,工作记忆的中介作用是抑郁症患者在时距复制任务中产生更大变异性的内部机制。

Objective:Exploring the performance of time reproduction task in patients with depression and the mediat⁃ing effects played by working memory and attentional networks.Methods:The study adopted a mixed experimental design of 2(group:depression group,normal group)x 5(standard duration:700ms,1700ms,2700ms,3700ms,4700ms),with group as the between-subjects variable and standard duration as the within-subjects variable.The dependent variable indicators were ration and coefficients of variation.Working memory was also measured by using the N-back task with indicators of re⁃sponse time and correctness.And the attentional network paradigm was used to measure attentional functions,as indicated by response time.Results:The depression group had longer reproduction intervals on 700 ms and 1700 ms and shorter re⁃production intervals on 4700 ms.The coefficients of variation at 700 ms,1700 ms,2700 ms,3700 ms and 4700 ms were sig⁃nificantly greater in the depression group than those in the normal group.Further mediation analyses found that correctness on the 2-back task mediated group and the coefficients of variation on 1700ms,2700ms,3700ms,and 4700ms,respective⁃ly.Conclusion:The depression group had a tendency to more overestimate the shorter time intervals and more underesti⁃mate the longer time intervals.Further mediation analyses revealed the mediating effect of working memory as an internal mechanism for greater variability in the time reproduction task.