Krakau Sofie, Chaieb Leila, Helmstaedter Christoph, von Wrede Randi, Fell Juergen
Department of Epileptology, University Hospital Bonn, Bonn, Germany.
Eur J Neurosci. 2020 Sep;52(5):3411-3418. doi: 10.1111/ejn.14743. Epub 2020 May 4.
Mind wandering refers to a shift of attention away from a task at hand to task-unrelated thoughts. Several groups have shown increased activation of the left medial temporal lobe (MTL) before and during spontaneous thoughts suggesting that the left MTL may play a crucial role in mind wandering. Due to its relevance for long-term memory, we further hypothesized that the left MTL is particularly involved in mind wandering towards the past. Accordingly, we predicted a reduced propensity to mind wander and less past-oriented mind wandering in patients with left MTL epilepsies. To this end, we experimentally investigated mind wandering in 89 in-patients undergoing diagnostic evaluation of their putative epileptic disorder. Patients performed a sustained attention to response task with embedded experience sampling probes aiming to assess occurrence, meta-awareness and temporal orientation (past/present/future) of mind-wandering episodes. We did not find significant differences in the propensity to mind wander between patient subgroups. However, the left MTL epilepsy subgroup showed significantly reduced past-oriented mind wandering compared to right MTL epilepsies, as well as a trend towards diminished past-oriented mind wandering compared to idiopathic epilepsies. Possibly due to compensatory mechanisms, the right MTL epilepsy subgroup showed significantly increased past-oriented mind wandering compared to extratemporal epilepsies and patients with syncopes. These behavioural findings point to a rejection of the hypothesis that the amount of time engaged in mind wandering crucially depends on the left MTL. However, our data do support the idea that the left MTL is particularly involved in mind wandering towards the past.
思绪游荡是指注意力从手头的任务转移到与任务无关的想法上。几个研究小组发现，在自发思考之前和期间，左内侧颞叶（MTL）的激活增加，这表明左MTL可能在思绪游荡中起关键作用。由于其与长期记忆的相关性，我们进一步假设左MTL特别参与向过去的思绪游荡。因此，我们预测左MTL癫痫患者思绪游荡的倾向会降低，且较少出现面向过去的思绪游荡。为此，我们对89名正在接受疑似癫痫疾病诊断评估的住院患者的思绪游荡进行了实验研究。患者执行一项持续注意力反应任务，并嵌入经验抽样探针，旨在评估思绪游荡发作的发生、元意识和时间取向（过去/现在/未来）。我们没有发现患者亚组之间在思绪游荡倾向上有显著差异。然而，与右MTL癫痫患者相比，左MTL癫痫亚组面向过去的思绪游荡显著减少，与特发性癫痫患者相比，也有减少面向过去思绪游荡的趋势。可能由于代偿机制，与颞叶外癫痫患者和晕厥患者相比，右MTL癫痫亚组面向过去的思绪游荡显著增加。这些行为学发现表明，关于思绪游荡所花费时间的多少关键取决于左MTL这一假设不成立。然而，我们的数据确实支持左MTL特别参与向过去的思绪游荡这一观点。
