认知负荷对疼痛共情的影响:来自ERP研究的证据

先前研究表明,对他人的疼痛共情受到多种因素的调节。认知负荷对疼痛共情的调节作用尚无研究。本研究使用事件相关电位技术探究高低认知负荷对疼痛共情神经加工过程的影响。实验通过不同长度的数字串记忆任务,形成高/低两种认知负荷,要求被试在不同认知负荷条件下观看他人处于疼痛/不疼痛情境下的图片,同时记录被试的在观看图片时的EEG数据。通过比较不同条件下观看图片诱发的ERP成分发现:早期成分P2和N2上认知负荷水平与图片类型出现了显著的交互作用,即在高认知负荷下疼痛图片诱发的波幅与非疼痛图片诱发的波幅差异显著,而低认知负荷下两种图片诱发的波幅差异不显著。这表明认知负荷主要影响疼痛共情加工的早期、自动化加工阶段。相比较于低认知负荷条件下,在高认知负荷下他人的疼痛获得了更好的加工。

Empathy for pain influenced by cognitive load:Evidence from an ERP study

Observing other in pain triggers the empathic responses, which involve two stages of processing temporally:an early, automatic processing that result in emotional contagion and affective sharing, and a later, cognitively controlled process related to emotional regulation. Previous studies suggest that this neural response can be modulated by numerous factors. However, no study has explored how working memory (WM) load can influence empathy for pain. Actually, almost every individual has to deal with other's emotions with concurrent cognitive task in everyday life. To explore how other's pain is processed under different cognitive load seems to be meaningful both theoretically and practically.In the present study, we investigated how different levels of working memory load can influence the processing of task-irrelevant stimuli showing other's pain. Twenty two healthy undergraduates (eleven males) participated in the 2×2 within-subject designed experiment (mean age 20 ± 2.4). We manipulated cognitive load by requiring participants to memorize two (low WM load) or six (high WM load) digits at the beginning of each trial. Then picture depicting a person's hands/forearms/feet in painful or non-painful situations was presented as a distractor. The participants were informed that these pictures were task-irrelevant and they should focus on memorizing the digits and they were required to judge if a given set of digits was the same as the one they saw at the beginning of the trial after the presentation of the picture. EEG during the observation of pictures under different WM loads was recorded by a 64-channel amplifier using a standard 10-20 system (Brain Products).The ERP results revealed that the WM load can influence the early automatic component P2 and N2. Comparing to low WM load, in the high WM-load condition, the painful pictures elicited significantly larger amplitudes in P2 and more negative amplitudes in N2 than the non-painful pictures. Meanwhile, under the low WM-load conditions, there was no significant difference between the painful and non-painful pictures.The present study found that the cognitive load mainly influence the early automatic stage of processing in empathy for pain. This result indicate that other's pain attracts greater attention and can be better processed when the cognitive control resources were depleted (i.e., under high, relative to low, concurrent WM load). Under high WM load, enhanced emotional sharing and affective arousal level was reflected in the effect observed on P2 and N2. These findings were explained from the perspective of load theory.