Task compliance predicts suppression-induced forgetting in a large sample

Peiduo Liu,Wenjing Yang,Michael C Anderson,Justin C Hulbert,Yuhua Guo,Jiang Qiu

doi:10.1038/s41598-021-99806-8

Abstract

Suppression-induced forgetting (SIF) refers to a memory impairment resulting from repeated attempts to stop the retrieval of unwanted memory associates. SIF has become established in the literature through a growing number of reports built upon the Think/No-Think (TNT) paradigm. Not all individuals and not all reported experiments yield reliable forgetting, however. Given the reliance on task instructions to motivate participants to suppress target memories, such inconsistencies in SIF may reasonably owe to differences in compliance or expectations as to whether they will again need to retrieve those items (on, say, a final test). We tested these possibilities on a large (N = 497) sample of TNT participants. In addition to successfully replicating SIF, we found that the magnitude of the effect was significantly and negatively correlated with participants’ reported compliance during the No-Think trials. This pattern held true on both same- and independent-probe measures of forgetting, as well as when the analysis was conditionalized on initial learning. In contrast, test expectancy was not associated with SIF. Supporting previous intuition and more limited post-hoc examinations, this study provides robust evidence that a lack of compliance with No-Think instructions significantly compromises SIF. As such, it suggests that diminished effects in some studies may owe, at least in part, to non-compliance—a factor that should be carefully tracked and/or controlled. Motivated forgetting is possible, provided that one is sufficiently motivated and capable of following the task instructions.

Highlights

Suppression-induced forgetting (SIF) refers to a memory impairment resulting from repeated attempts to stop the retrieval of unwanted memory associates
suppression-induced forgetting (SIF) often generalizes from cued-recall tests using the originally learned cue to independent probes (IPs; e.g., either a semantic category cue with word stems; or a second, studied cue associated to the original response)
Five participants were removed from the eventual data analysis as they asked to withdraw early from the study because they indicated becoming uncomfortable being in the MRI scanner for the full duration of the TNT phase, leaving 141 participants contributing to the analysis of SIF and facilitation effects

Summary

Introduction

Suppression-induced forgetting (SIF) refers to a memory impairment resulting from repeated attempts to stop the retrieval of unwanted memory associates. Given the reliance on task instructions to motivate participants to suppress target memories, such inconsistencies in SIF may reasonably owe to differences in compliance or expectations as to whether they will again need to retrieve those items (on, say, a final test). The TNT paradigm, introduced by Anderson and G reen[11], was developed to empirically test the ability to suppress unwanted memories by measuring a predicted aftereffect of repeated memory stoppage: suppressioninduced forgetting. Participants undergoing this procedure typically are first asked to learn cue-target word pairs to criterion (e.g., 50%) before proceeding to the critical TNT phase of the experiment. Additional evidence supporting the inhibition account stems from a growing number of neuroimaging studies of healthy adults pointing to a prefrontally mediated top-down inhibition of brain regions supporting aspects of the target memory representation[10]

Methods

Results

Discussion

Conclusion