Benoit Roland G, Werkle-Bergner Markus, Mecklinger Axel, Kray Jutta
Experimental Neuropsychology Unit, Saarland University, Saarbrücken 66041, Germany.
Brain Cogn. 2009 Jun;70(1):123-35. doi: 10.1016/j.bandc.2009.01.004. Epub 2009 Feb 28.
This study investigated preparatory processes involved in adapting to changing episodic memory retrieval demands. Event-related potentials (ERPs) were recorded while participants performed a general old/new recognition task and a specific task that also required retrieval of perceptual details. The relevant task remained either constant or changed (predictably or randomly) across trials. Responses were slowed when participants switched from the specific to the general task but not vice versa. Hence, asymmetrical switch costs were observed, suggesting that retrieval preparation is dependent not only on the current retrieval goal but also influenced by recent retrieval attempts. Consistently, over posterior scalp regions ERPs associated with advance preparation were modulated by the preceding task, reflecting increased attentional selection requirements for the general task, and by the foreknowledge about the task sequence. When retrieval demands remained constant, frontal slow-waves elicited by retrieval-cues were more positive going for the specific task, indicating full implementation of a retrieval orientation that allows more efficient retrieval of perceptual details.
本研究调查了适应不断变化的情景记忆检索需求所涉及的准备过程。在参与者执行一般的旧/新识别任务以及还需要检索感知细节的特定任务时，记录了事件相关电位（ERP）。相关任务在各试验中保持不变或发生变化（可预测地或随机地）。当参与者从特定任务切换到一般任务时反应变慢，反之则不然。因此，观察到不对称的切换成本，这表明检索准备不仅取决于当前的检索目标，还受到近期检索尝试的影响。一致地，在头皮后部区域，与提前准备相关的ERP受到先前任务的调制，反映出一般任务对注意力选择要求的增加，以及受到关于任务序列的预知的影响。当检索需求保持不变时，由检索线索引发的额叶慢波在特定任务中更正相，表明检索取向的充分实施，这允许更有效地检索感知细节。
