Differentiating the DF effect in episodic memory: evaluating the contribution of the procedures of collaborative memory.

Existing research has demonstrated a significant directed forgetting (DF) effect in memory. However, it remains unclear whether this phenomenon would occur in the context of interpersonal collaboration. Additionally, the contribution of emotional valence to the DF effect in item memory and source memory (which are subtypes of episodic memory) also needs to be explored. To address these issues, we conducted two experiments that combined the collaborative memory paradigm with the item-method procedure of DF. In both experiments, positive, neutral, or negative words were presented as stimuli, each followed by an R/F cue during encoding. We conducted two recalls, labeled Recall 1 and Recall 2, which consisted of both memory tasks. Recall 1 was performed either individually or collaboratively, whereas Recall 2 was done individually. Experiment 1 and Experiment 2 adopted the free-flowing procedure and the turn-taking procedure of collaborative memory, respectively. We obtained three implications from our current findings. (a) The occurrence of the DF effect in item memory was found regardless of the procedure of collaborative memory, and it was insensitive to the emotional valence of words or to whether participants had collaborated or not. These patterns demonstrate that both the mechanisms of elaborative rehearsal and active suppression/encoding blocking were engaged across words of different emotional valences and in nominal and collaborative circumstances. (b) In source memory, the DF effect showed different patterns in ongoing and post-collaborative memory, which underpins the dual-process models. (c) The amplitude of the DF effect was sensitive to the interaction of emotional valence by the status of collaboration, and the impact of collaboration differed between the two experiments, offering telling evidence of different aspects of the retrieval strategy disruption hypothesis (RSDH). Directions for identifying more influential factors are put forward.