Stramaccia Davide F, Penolazzi Barbara, Altoè Gianmarco, Galfano Giovanni
Department of Developmental and Social Psychology, University of Padova, Padova, Italy; Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
Department of Life Sciences, University of Trieste, Trieste, Italy.
Neurobiol Learn Mem. 2017 Oct;144:114-130. doi: 10.1016/j.nlm.2017.07.005. Epub 2017 Jul 11.
Retrieving information from episodic memory may result in later inaccessibility of related but task-irrelevant information. This phenomenon, known as retrieval-induced forgetting, is thought to represent a specific instance of broader cognitive control mechanisms, that would come into play during memory retrieval, whenever non-target competing memories interfere with recall of target items. Recent neuroimaging studies have shown an association between these mechanisms and the activity of the right Prefrontal Cortex. However, so far, few studies have attempted at establishing a causal relationship between this brain region and behavioural measures of cognitive control over memory. To address this missing link, we delivered transcranial Direct Current Stimulation (tDCS) over the right Inferior Frontal Gyrus (rIFG) during a standard retrieval-practice paradigm with category-exemplar word pairs. Across two experiments, tDCS abolished retrieval-induced forgetting to different degrees, compared to the sham control group whereas no effects of stimulation emerged in an ancillary measure of motor stopping ability. Moreover, influence analyses on specific subsets of the experimental material revealed diverging patterns of results, which depended upon the different categories employed in the retrieval-practice paradigm. Overall, the results support the view that rIFG has a causal role in the control of interference in memory retrieval and highlight the often underestimated role of stimulus material in affecting the effects. The present findings are therefore relevant in enriching our knowledge about memory functions from both a theoretical and methodological perspective.
从情景记忆中提取信息可能会导致相关但与任务无关的信息在之后难以获取。这种现象被称为提取诱发遗忘，被认为是更广泛的认知控制机制的一个具体实例，每当非目标竞争记忆干扰目标项目的回忆时，该机制就会在记忆提取过程中发挥作用。最近的神经影像学研究表明，这些机制与右侧前额叶皮层的活动之间存在关联。然而，到目前为止，很少有研究试图在这个脑区与对记忆的认知控制的行为测量之间建立因果关系。为了解决这个缺失的环节，我们在一个使用类别-范例词对的标准提取练习范式中，对右侧额下回（rIFG）进行经颅直流电刺激（tDCS）。在两个实验中，与假刺激对照组相比，tDCS在不同程度上消除了提取诱发遗忘，而在运动停止能力的辅助测量中未出现刺激效应。此外，对实验材料特定子集的影响分析揭示了不同的结果模式，这取决于提取练习范式中使用的不同类别。总体而言，结果支持这样一种观点，即rIFG在控制记忆提取中的干扰方面具有因果作用，并突出了刺激材料在影响效应方面经常被低估的作用。因此，本研究结果从理论和方法两个角度丰富了我们对记忆功能的认识。
