Different reactivation procedures enable or prevent episodic memory updating

Abstract

The present study asked whether the specific method of reactivation modulates the impact of new learning on reactivated episodic memories. The study consisted of three sessions that were spaced 48 hr apart. It used an ABAC paradigm that allowed for the simultaneous assessment of retroactive interference (RI: reduced A–B recall after A–C learning) and intrusions from C into A–B recall. In Session 1, participants learned a list of paired‐associates A–B. In Session 2, memory for A–B was reactivated or not and then participants either learned a second list of paired‐associates A–C or completed a control task. Three different reminder conditions were compared to a no‐reminder condition: a test condition, in which participants were asked to recall B in response to A, a restudy condition, in which A–B pairs were presented again for study, and a cue‐word only reminder condition, in which A cues were presented in an unrelated rating task. In Session 3, recall of A–B was tested. Moderate or indirect reactivation of A–B (presentation of cue‐words only) resulted in high RI effects and intrusion rates, whereas strong and direct reactivation (test and restudy) drastically reduced these effects. We suggest that direct reactivation of A–B before A–C learning strengthens memory and draws attention to list differences, thereby enhancing list segregation, and reducing memory updating.

Generalising reconsolidation: Spatial context and prediction error

“…Experiment 2 bolstered prior findings that prediction error triggers reconsolidation and extended them by showing that the error can come in different forms, some quite obvious. The results of this type of blatant manipulation are in some conflict with previous findings that the error must be neither to small nor too large to destabilize a memory and trigger reconsolidation (e.g., Forcato et al, 2009;Scully & Hupbach, 2019). Moreover, most prediction error manipulations occur within the memory task itself, rather than as part of a different task.…”

“…Studies have shown that spatial context is special in its ability to trigger reconsolidation in comparison to other context cues (as long as it is an unfamiliar context, Hupbach et al, 2009), though it is still not clear why that is and whether there are any other context cues that may work (Hupbach et al, 2008). Scully and Hupbach (2019) showed that the degree of activation of List 1 was linked to the intrusion rate of List 2 items into List 1, such that only specific reminders were effective in producing memory updating. Reminders that were too weak or too strong did not produce a memoryupdating pattern.…”

Sleep enhances reconsolidation-based strengthening of visuospatial memories

“…Notably, we do not see a larger effect of reactivation in the wake group compared to the sleep group, suggesting that if context effects were present they were relatively small compared to the main reactivation effect driven by the recall test. Nonetheless, direct and indirect reminders may have different consequences 36 , and so future studies controlling for spatial context are warranted. Finally, our sample sizes in sleep physiology analyses were somewhat low, particularly with regard to Experiment 2, and samples were unbalanced with regard to gender (majority female).…”

“…The fact that new learning did not directly conflict with the original memory, as was the case in some previous studies 15 , 20 , may have allowed for strengthening rather than interference. Additionally, using a test as the reminder protects from retroactive interference compared to a weaker/indirect reminder 36 , and may allow for better memory segregation 37 . Reconsolidation also leads to strengthening when reactivation is followed by re-learning of the same material 21 , 22 , mild stress 9 , 10 , exercise 11 , or pharmacological interventions 38 .…”

What happened when? Brain and behavioral responses to modified structure and content in episodic cueing

“…learning a list or watching a video; e.g. [22,23]). In the present study, we therefore aimed to extend the understanding of mnemonic prediction errors at the neural and behavioral level by selectively targeting predictions about two different aspects of episodic memories, either their content ("what") or their structure ("when").…”