Item-method Directed Forgetting Paradigm Research Articles

Forgetting cues are ineffective in promoting forgetting in the item-method directed forgetting paradigm

This study aims to investigate the effectiveness of forgetting cues in an item-method directed forgetting (DF) paradigm. A modified no-cue (NC) condition, in which participants could not adopt intentional forgetting strategy, was added to an item-method DF paradigm. Memory retention was compared between NC condition and to-be-forgotten (TBF) condition. The results revealed that the recognition reaction times (RTs) were shorter for the remembered TBF (TBF-R) words than for the remembered NC (NC-R) words, and were longer for the forgotten TBF words relative to the forgotten NC words, indicating that participants might be more familiar with the TBF words than the NC words. Event-related potential results showed that both LPC activity and frontal old/new effect were enhanced for TBF-R words relative to the NC-R words. These results might indicate that participants were more familiar with TBF words than NC words. This study further supports the view that forgetting cues may not in fact promote forgetting in the item-method DF paradigm.

Elaborately rehearsed information can be forgotten: A new paradigm to investigate directed forgetting.

In previous item-method directed forgetting (DF) studies, forgetting may have occurred when the maintenance rehearsal of memory items was performed. In this study, a modified item-method DF paradigm was adopted to investigate whether forgetting instruction could produce a positive effect on forgetting the items that were elaborately rehearsed. During the study phase, a to-be-forgotten (TBF) word was followed by a forgetting cue. If no cue followed, the word was a to-be-remembered (TBR) item. Participants were required to intentionally memorize the word when it appeared. During the test phase, a yes/no recognition (Experiment 1) or a remember/know procedure (Experiment 2) was adopted. The behavioural results revealed that both the hit rate (Experiment 1) and remembering rate (Experiment 2) were higher for TBR relative to TBF words. For correctly identified old words, reaction times were consistently shorter for TBR compared to TBF words. These results revealed superior memory retention for TBR than for TBF words. The event-related potential (ERP) results revealed that, during both FN400 and late-positive complex (LPC) time windows, the remembered TBR words evoked more positive ERPs than the remembered TBF words and correctly rejected (CR) words (i.e., FN400 and LPC old/new effects). However, more negative ERPs were evoked for both remembered and forgotten TBF words than for CR words during the LPC time window (i.e., reversed LPC old/new effect). These results demonstrated that TBF words were associated with lower level of familiarity and recollection process than TBR words. The memory representation of TBF information might be inhibited.

Can self-referential information improve directed forgetting? Evidence from a multinomial processing tree model.

A large body of research has shown that self-referential processing can enhance an individual’s memory of information. However, there are many arguments about how self-referential processing affects directed forgetting (DF). In this study, two experiments were designed to investigate the DF effect and its internal psychological mechanism under explicit and implicit referential conditions using the item-method DF paradigm combined with the storage-retrieval MPT model. We compare the difference in the DF effect between self-referential and other-referential conditions and explain the reasons for the difference. Our results suggest that the item-method DF effect is the result of a selective rehearsal mechanism and a retrieval inhibition mechanism working together. Both self-reference and other-reference can cause DF in explicit referential processing or implicit referential processing, although the DF effect is stronger under the self-referential condition. Furthermore, the memory advantage effect of implicit self-referential processing is stronger than that of explicit self-referential processing.

Frontal Control Process in Intentional Forgetting: Electrophysiological Evidence.

In this study, we aimed to seek for the neural evidence of the inhibition control process in directed forgetting (DF). We adopted a modified item-method DF paradigm, in which four kinds of cues were involved. In some trials, the words were followed by only a forgetting (F) cue. In the other trials, after a word was presented, a maintenance (M) cue was presented, followed by an explicit remembering (M-R) cue or an forgetting (M-F) cue. Data from 19 healthy adult participants showed that, (1) compared with the remembering cue (i.e., M-R cue), forgetting cues (i.e., M-F cue and F cue) evoked enhanced frontal N2 and reduced parietal P3 and late positive complex (LPC) components, indicating that the forgetting cues might trigger a more intensive cognitive control process and that fewer amounts of cognitive resources were recruited for the further rehearsal process. (2) Both the M cue and the F cue evoked enhanced N2 and decreased P3 and LPC components than the M-R or M-F cue. These results might indicate that compared with the M-R and M-F cues, both the M and F cues evoked a more intensive cognitive control process and decreased attentional resource allocation process. (3) The F cue evoked a decreased P2 component and an enhanced N2 component relative to the other cues (i.e., M-R, M-F, M), indicating that the F cue received fewer amounts of attentional resources and evoked a more intensive cognitive control process. Taken together, forgetting cues were associated with enhanced N2 activity relative to the maintenance rehearsal process or the remembering process, suggesting an enhanced cognitive control process under DF. This cognitive control process might reflect the role of inhibition in DF as attempting to suppress the ongoing encoding.

The challenge of forgetting: Neurobiological mechanisms of auditory directed forgetting.

Directed forgetting (DF) is considered an adaptive mechanism to cope with unwanted memories. Understanding it is crucial to develop treatments for disorders in which thought control is an issue. With an item-method DF paradigm in an auditory form, the underlying neurocognitive processes that support auditory DF were investigated. Subjects were asked to perform multi-modal encoding of word-stimuli before knowing whether to remember or forget each word. Using functional magnetic resonance imaging, we found that DF is subserved by a right frontal-parietal-cingulate network. Both qualitative and quantitative analyses of the activation of this network show converging evidence suggesting that DF is a complex process in which active inhibition, attentional switching, and working memory are needed to manipulate both unwanted and preferred items. These results indicate that DF is a complex inhibitory mechanism which requires the crucial involvement of brain areas outside prefrontal regions to operate over attentional and working memory processes. Hum Brain Mapp 39:249-263, 2018. © 2017 Wiley Periodicals, Inc.

Neurophysiological correlates of emotional directed-forgetting in persons with Schizophrenia: An event-related brain potential study

BackgroundRecent research has shown that patients with schizophrenia (SCZ) exhibit reduced directed forgetting (DF) for negative words, suggesting impaired ability to instantiate goal-directed inhibition in order to suppress a competing, emotion-driven responses (i.e., emotional memory enhancement). However, disrupted inhibition is not the only possible mechanism by which patients could manifest reduced emotional DF. Therefore, the primary objective of the current study was to use event-related brain potential (ERP) recordings to investigate alternative hypotheses. MethodsERPs were recorded while patients and controls completed an item-method DF paradigm using negative and neutral words. The N2 indexed goal-directed inhibition of to-be-forgotten items. The late positive potential (LPP) indexed emotional memory enhancement for negative study items. The P300 indexed selective rehearsal of to-be-remembered items. ResultsThe SCZ group exhibited a reduced DF effect overall, but this was not modulated by emotion. N2 amplitude at anterior sites was larger for forget versus remember cues in the control group only, but this effect was not modulated by emotion. LPP amplitude was greater for negative versus neutral words in both groups, independent of region. P300 amplitude at posterior sites was greater for remember versus forget cues in the control group only. DiscussionThese data suggest that reduced DF in SCZ may be due, in part, to both diminished goal-directed inhibition of to-be-forgotten items and reduced selective rehearsal of to-be-remembered items. However, these data do not support the hypothesis that goal-directed, inhibitory processes are disrupted by competing, emotion-driven processes in SCZ. Patients' ERP data also suggested that they did not exhibit disproportionately heightened encoding of emotional stimuli, nor did they have deficient selective rehearsal of to-be-remembered emotional items.

The Role of Memory Traces Quality in Directed Forgetting: A Comparison of Young and Older Participants.

A reduced directed-forgetting (DF) effect in normal aging has frequently been observed with the item method. These results were interpreted as age-related difficulties in inhibiting the processing of irrelevant information. However, since the performance of older adults is usually lower on items to remember, the age effect on DF abilities could also be interpreted as reflecting memory problems. Consequently, the present study aimed at investigating the influence of memory traces quality on the magnitude of the DF effects in normal aging. We predicted that increasing the quality of memory traces (by increasing presentation times at encoding) would be associated with attenuated DF effects in older participants due to the increased difficulty of inhibiting highly activated memory traces. A classical item-method DF paradigm was administered to 48 young and 48 older participants under short and long encoding conditions. Memory performance for information to memorize and to suppress was assessed with recall and recognition procedures, as well as with a Remember/Know/Guess (RKG) paradigm. The results indicated that, when memory traces are equated between groups, DF effects observed with the recall, recognition and RKG procedures are of similar amplitude in both groups (all ps>0.05). This suggests that the decreased DF effect previously observed in older adults might not actually depend on their inhibitory abilities but may rather reflect quantitative and qualitative differences in episodic memory functioning.

Effects of memory instruction on attention and information processing: Further investigation of inhibition of return in item-method directed forgetting

In the item-method directed-forgetting paradigm, the magnitude of inhibition of return (IOR) is larger after an instruction to forget (F) than after an instruction to remember (R). In the present experiments, we further investigated this increased magnitude of IOR after F as compared to R memory instructions (dubbed the F > R IOR difference), in order to understand both the consequences for information processing and the purpose of the differential withdrawal of attention that results in this difference. Words were presented in one of four peripheral locations, followed by either an F or an R memory instruction. Then, a target appeared in either the same location as the previous word or one of the other locations. The results showed that the F > R IOR difference cannot be explained by attentional momentum (Exp. 1), that the spatial compatibility of the response options with target locations is not necessary for the F > R IOR difference to emerge (Exp. 2), and that the F > R IOR difference is location-specific rather than response-specific (Exp. 3). These results are consistent with the view that F > R IOR represents a bias against responding to information emanating from an unreliable source (Taylor & Fawcett, 2011).