How do word frequency and memory task influence directed forgetting: An ERP study

• Published in: International journal of psychophysiology 2019-12, Vol.146, p.157-172
• Main Authors: Ye, Jingheng, Nie, Aiqing, Liu, Si
• Format: Article
• Language: English
• Subjects: DF effect; Directed forgetting; ERP old/new effect; Item memory; Source memory; Word frequency
• ISSN: 0167-8760; 1872-7697
• DOI: 10.1016/j.ijpsycho.2019.10.005

In daily life, it is important either to remember sometimes or to intentionally forget on other occasions. The issue of forgetting following instructions (i.e. directed forgetting, DF) has been broadly studied; however, whether the frequency of contents would matter in DF remains unclear, and the understanding of its neural mechanism in both circumstances of item memory and source memory requires improvement in depth. For these purposes, the current study manipulated word frequency and memory task to investigate relevant behavioral features and neural activities of DF. Adopting event-related potential (ERP) technique, this study applied two-character Chinese words of two types of word frequency (high vs low) in the item-method DF paradigm. During encoding, we found that the increased frontal positivity, an index of active inhibition, was regulated by both word frequency and memory task, while the enhanced parietal positivity reflecting selective rehearsal didn't fluctuate across conditions. In the course of test, three ERP old/new effects were identified: the familiarity-based FN400 and the recollection-driven LPC were both modulated by word frequency and memory task, but the right frontal old/new effect was significant solely in source memory; also, these effects provided compelling evidence for the influences of word frequency and memory task on DF. Our results reinforce the differentiation between absolute familiarity and relative familiarity in memory, reveal their sensitivity to DF, and also support the dual-process interpretation. Implications are made to examine more influential factors for future research. •Whether content frequency matters in directed forgetting (DF) remains unclear.•This study explored the modulations of word frequency and memory task on DF.•Both selective rehearsal and active inhibition were affected by these two factors.•Familiarity- and recollection-based process of DF mapped onto the old/new effects.•The right frontal old/new effect was merely significant in source memory.