Neural modulation of directed forgetting by valence and arousal: An event-related potential study

Abstract

Intentional forgetting benefits memory by removing no longer needed information and promoting processing of more relevant materials. This study sought to understand how the behavioural and neurophysiological representation of intentional forgetting would be impacted by emotion. We took a novel approach by examining the unique contribution of both valence and arousal on emotional directed forgetting. Participants completed an item directed forgetting task for positive, negative, and neutral words at high and lower levels of arousal while brain activity was recorded using electroencephalography (EEG). Behaviourally, recognition of to-beremembered (TBR) and to-be-forgotten (TBF) items varied as a function of valence and arousal with reduced directed forgetting for high arousing negative and neutral words. In the brain, patterns of frontal and posterior activation in response to TBF and TBR cues respectively replicated prior EEG evidence to support involvement of inhibitory and selective rehearsal mechanisms in item directed forgetting. Interestingly, emotion only impacted cue-related posterior activity, which varied depending on specific interactions between valence and arousal.Together, results suggest that the brain handles valence and arousal differently and highlights the importance of considering in a collective manner the multidimensional nature of emotion in experimentation.

Too hard to forget? ERPs to remember, forget, and uninformative cues in the encoding phase of item‐method directed forgetting

“…other findings from item-method directed forgetting (Bailey & Chapman, 2012;Gallant & Dyson, 2016;Hauswald et al, 2010) and have been previously related to findings of the LPP predicting subsequent memory performance (Dolcos & Cabeza, 2002). However, these previous findings have observed this ERP effect for TBR cues and related the effect to the standard finding of better recognition of TBR than TBF items, since no previous study has included uninformative items and cues.…”

“…For TBR items, this rehearsal is thought to persist during presentation of the remember cue, whereas for TBF items the rehearsal process is thought to be terminated upon presentation of the forget cue, leading to passive decay of their memory trace (Basden, Basden, & Gargano, 1993). In line with this selective rehearsal account, ERP studies have revealed larger parietal late positive potentials in response to TBR cues than to TBF cues (Bailey & Chapman, 2012;Gallant & Dyson, 2016;Gao et al, 2016;Hauswald, Schulz, Iordanov, & Kissler, 2010). Also consistent with selective rehearsal, the item-method directed forgetting effect is thought to result primarily from processes occurring during encoding rather than retrieval (e.g., Basden et al, 1993;Geraerts & McNally, 2008).…”

“…Based on these results, interspersing UI items as a functional baseline may help to clarify the functional significance of ERPs elicited by TBF cues and TBR cues at different temporal processing stages: The direction and timing of differences between TBR cues, TBF cues, and UI baseline cues should provide information on the cognitive processes recruited by each instruction. As indicated above, neuroscience measures have been used successfully in item-method directed forgetting research (e.g., Bailey & Chapman, 2012;Gallant & Dyson, 2016;Gao et al, 2016;Hauswald et al, 2010;Ullsperger et al, 2000;van Hooff & Ford, 2011), and differences between TBR-and TBF-associated ERPs have been established. Past studies have implicated not only attentional orienting (Gao et al, 2016), selective rehearsal (Hauswald et al, 2010), and memory encoding (Bailey & Chapman, 2012), but also executive control and inhibition (Hauswald et al, 2010;Ullsperger et al, 2000;van Hooff & Ford, 2011) in this paradigm.…”

“…In general, frontal positivities are interpreted as reflecting control processes in long-term memory, indexing retrieval inhibition, but also more generally retrieval orientation (for review, see Mecklinger, 2010). The late parietal positivity enhancement for TBR compared to TBF cues (e.g., Bailey & Chapman, 2012;Brandt, Nielsen, & Holmes, 2013;Gallant & Dyson, 2016;Hauswald et al, 2010) is thought to indicate superior encoding of TBR items, contributing to their subsequent better recognition in the testing phase. This is consistent with a general role of late parietal positivities (LPP) in memory formation (e.g., Dolcos & Cabeza, 2002).…”

Local context effects during emotional item directed forgetting in younger and older adults

“…Some theories argue that the high priority TBR items are selectively rehearsed in order to strengthen their trace in memory while low priority TBF items are dropped from such rehearsal processes (Basden & Basden, 1996). Other theories suggest that "forgetting" of TBF items is facilitated by an attentional inhibition mechanism that diminishes processing of these items (Fawcett & Taylor, 2008;Gallant & Dyson, 2016;Wylie, Fawcett, & Taylor, 2008). Whether the cognitive operations elicited by these cues would impact memory of items in close temporal proximity and how this differs across age groups has yet to be explored.…”