Forget Instruction Research Articles

Memory modulation: Dominance of negative visual context over neutral verbal memory.

Neutral memories can be modulated via intentional memory control paradigms such as directed forgetting. In addition, previous studies have shown that neutral visual memories can be modulated indirectly, via remember and forget instructions towards competing verbal memories. Here we show that direct modulation of neutral verbal memory strength is impaired by negative visual context, and that negative visual context is resistant to indirect memory modulation. Participants were directly instructed to intentionally remember or forget newly encoded neutral verbal information. Importantly, this verbal information was interleaved with embedded negative visual context. Results showed that negative visual context eliminated the well-documented effect of direct instructions to intentionally remember verbal content. Furthermore, negative visual memory was highly persistent, overcoming its sensitivity to indirect modulation shown in previous studies. Finally, these memory effects persisted to the following day. These results demonstrate the dominance of negative visual context over neutral content, highlighting the challenges associated with memory modulation in psychopathologies involving maladaptive processing of negative visual memories.

The role of prior familiarisation and meaningfulness of verbal and visual stimuli on directed forgetting

ABSTRACT Intentional forgetting of unwanted information is a crucial cognitive function that is often studied with directed forgetting (DF) procedure, whereby cuing some study materials with Forget (F) instruction impairs their memory compared to cuing with Remember (R) instruction. This study investigates how the nature of information (verbal or pictorial), its semantic significance (meaningful or meaningless), and the degree of prior episodic familiarity influence DF. Before the DF phase, stimuli were familiarised by pre-exposing them 0, 2, or 6 times in a prior preview phase. Finally, memory for all items was assessed with old/new recognition test. Experiment 1 employed words, Experiment 2 utilised fractal images, Experiment 3 featured both meaningful and meaningless object images, and Experiment 4 used words and nonwords. Our results indicate that materials that produced better memory performance are not always harder to intentionally forget. Previewed items showed reduced DF compared to non-previewed items regardless of the nature of information, and meaningless stimuli are challenging to intentionally forget regardless of their degrees of familiarisation unless they are meaningless verbal materials. Collectively, the results highlight the importance of joint consideration of the stimulus format, its meaningfulness, and its episodic familiarity in understanding conditions that interact with intentional forgetting.

Let me give you something to think about: Does needing to remember something new make it easier to forget something old?

In an item-method directed forgetting task, memory instructions presumably operate by promoting further rehearsal of to-be-remembered (TBR) items and limiting encoding of to-be-forgotten (TBF) items. We asked whether diverting attentional resources away from TBF items and towards a new item that needed to be committed to memory would improve forgetting. To this end, study words in our experiments were presented singly followed by a remember instruction (single-TBR), by a forget instruction (single-TBF), or else were replaced by a new word to be remembered (replace-TBR) in place of the original study word which could be forgotten (replace-TBF). A typical directed forgetting effect was observed across single and replace trials. However, there was no compelling evidence that forgetting was better for replace-TBF compared to single-TBF words, suggesting that, by itself, the explicit redirection of attentional and other processing resources away from forget items may not be sufficient to improve item-method directed forgetting.

A computational account of item-based directed forgetting for nonwords: Incorporating orthographic representations in MINERVA 2.

Recent research on item-method directed forgetting demonstrates that forget instructions not only decrease recognition for targets, but also decrease false recognition for foils from the same semantic categories as targets instructed to be forgotten. According to the selective rehearsal account of directed forgetting, this finding suggests that remember instructions may engage elaborative rehearsal of the category-level information of items. In contrast to this explanation, Reid and Jamieson (Canadian Journal of Experimental Psychology / Revue canadienne de psychologie expérimentale, 76(2), 75-86, 2022) proposed that the differential rates of false recognition may emerge at retrieval when foils from "remember" and "forget" categories are compared to traces in memory. Using MINERVA S, an instance model of memory based on MINERVA 2 that incorporates structured semantic representations, Reid and Jamieson successfully simulated lower false recognition for foils from "forget" categories without assuming rehearsal of category-level information. In this study, we extend the directed forgetting paradigm to categories consisting of orthographically related nonwords. Presumably participants would have difficulty rehearsing category-level information for these items because they would have no pre-experimental knowledge of these categories. To simulate the findings in MINERVA S, we imported structured orthographic representations rather than semantic representations. The model not only predicted differential rates of false recognition for foils from "remember" and "forget" categories, but also predicted higher rates of false recognition overall than what was observed for semantic categories. The empirical data closely matched these predictions. These data suggest that differential rates of false recognition due to remember and forget instructions emerge at retrieval when participants compare recognition probes to traces stored in memory.

Different ways to forget: Electrophysiological mechanisms underlying item-method directed forgetting of angry and neutral faces.

Emotional stimuli, including faces, receive preferential processing and are consequently better remembered than neutral stimuli. Therefore, they may also be more resistant to intentional forgetting. The present study investigates the behavioral and electrophysiological consequences of instructions to selectively remember or forget angry and neutral faces. In an item-method directed forgetting experiment, angry and neutral faces were randomly presented to 25 student participants (4 males). Each face was followed by an instruction to either forget or remember it and the participants’ EEG was recorded. Later, recognition memory was unexpectedly tested for all items. Behaviorally, both hit and false alarm rates were higher for angry alike than for neutral faces. Directed forgetting occurred for neutral and angry faces as reflected in a reduction of both recognition accuracy and response bias. Event-related potentials revealed a larger late positive potential (LPP, 450 – 700 ms) for angry than for neutral faces during face presentation and, in line with selective rehearsal of remember items, a larger LPP following remember than forget cues. Forget cues generally elicited a larger frontal N2 (280 – 400 ms) than remember cues, in line with the forget instruction eliciting conflict monitoring and inhibition. Selectively following angry faces, a larger cue-evoked P2 (180 – 280 ms) was observed. Notably, forget cues following angry faces elicited a larger late frontal positivity (450 - 700 ms) potentially signaling conflict resolution. Thus, whereas both angry and neutral faces are subject to directed forgetting, on a neural level, different mechanisms underlie the effect. While directed forgetting for neutral faces may be achieved primarily by selective rehearsal, directed forgetting of angry faces involves an additional late frontal positivity, likely reflecting higher cognitive demands imposed by forgetting angry faces.

Effects of anxiety level on directed forgetting of emotional information and related metacognitive judgments

The present study investigated intentional forgetting of emotional information in low vs. high anxiety groups, by using a directed forgetting paradigm. The groups were formed based on their scores on measures of state and trait anxiety. Participants were provided with positive, negative, and neutral photographs with either remember or forget instructions and further provided metacognitive judgments of learning for each photograph, indicating how likely they are to recognize the photograph in a subsequent recognition test. In the recognition test, they identified the photographs that they had seen in the learning session, irrespective of instruction. The results showed that directed forgetting was only observed in the high anxiety group. Furthermore, higher anxiety scores negatively correlated with the recognition of negative to-be-forgotten information, indicating that high anxiety is associated with a better ability to forget negative information. Metacognitive judgments showed awareness of the forget instructions and the valence of the photographs, but they were not affected by anxiety level. The results suggest that the effects of anxiety on cognitive control may be different between participants with higher vs. lower anxiety levels in a non-clinical sample. The results are discussed within several theoretical frameworks which claim that anxiety may lead to the inhibition and avoidance of negatively valenced mental content.

Selective directed forgetting of motor sequences

We examined selective directed forgetting in motor memory using a new variant of a three-list approach, to distinguish between accounts of directed forgetting. Participants consecutively studied three lists (L1, L2, and L3) of four sequential four-finger movements each. After studying L2, participants in the forget group were instructed to selectively forget the just studied four items of L2 but to retain the previously studied four items of L1, whereas the remember group did not receive any forget instruction for L2 but was encouraged to retain the items of both lists. In addition, we switched (switch groups) or repeated the items-enacting hand (no-switch groups) between L2 and L3 for a manipulation of post-forget-cue material competition for L2. A final memory test assessed recall performance for all three lists. Selective directed forgetting (lower L2 recall in the forget group as compared to the remember group) only occurred if the same hand was used for L2 and L3 (high interference between L2 and L3 encoding) whereas no selective directed forgetting occurred if the hand switched between L2 and L3 (low interference between L2 and L3 encoding). These results suggest that an inhibitory mechanism caused (selective) directed-forgetting costs that was triggered when items studied after the forget instruction had the potential to interfere with already stored items (i.e. were to be enacted by the same hand). When subsequently studied items pertained to the other hand no directed-forgetting costs occurred.

Separation of item and context in item-method directed forgetting

Contextual information plays a critical role in directed forgetting (DF) of lists of items, whereas DF of individual items has been primarily associated with item-level processing. This study was designed to investigate whether context processing also contributes to the forgetting of individual items. Participants first viewed a series of words, with task-irrelevant scene images (used as “context tags”) interspersed between them. Later, these words reappeared without the scenes and were followed by an instruction to remember or forget that word. Multivariate pattern analyses of fMRI data revealed that the reactivation of context information associated with the studied words (i.e., scene-related activity) was greater whereas the item-related information diminished after a forget instruction compared to a remember instruction. Critically, we found the magnitude of the separation between item information and context information predicted successful forgetting. These results suggest that the unbinding of an item from its context may support the intention to forget, and more generally they establish that contextual processing indeed contributes to item-method DF.

Metamemory and Memory Discrepancies in Directed Forgetting of Emotional Information.

Directed Forgetting (DF) studies show that it is possible to exert cognitive control to intentionally forget information. The aim of the present study was to investigate how aware individuals are of the control they have over what they remember and forget when the information is emotional. Participants were presented with positive, negative and neutral photographs, and each photograph was followed by either a Remember or a Forget instruction. Then, for each photograph, participants provided Judgments of Learning (JOLs) by indicating their likelihood of recognizing that item on a subsequent test. In the recognition phase, participants were asked to indicate all old items, irrespective of instruction. Remember items had higher JOLs than Forget items for all item types, indicating that participants believe they can intentionally forget even emotional information—which is not the case based on the actual recognition results. DF effect, which was calculated by subtracting recognition for Forget items from Remember ones was only significant for neutral items. Emotional information disrupted cognitive control, eliminating the DF effect. Response times for JOLs showed that evaluation of emotional information, especially negatively emotional information takes longer, and thus is more difficult. For both Remember and Forget items, JOLs reflected sensitivity to emotionality of the items, with emotional items receiving higher JOLs than the neutral ones. Actual recognition confirmed better recognition for only negative items but not for positive ones. JOLs also reflected underestimation of actual recognition performance. Discrepancies in metacognitive judgments due to emotional valence as well as the reasons for underestimation are discussed.

Directed forgetting instructions decrease proactive interference within working memory below that of a baseline encode-only condition

ABSTRACT Directed forgetting involves the targeted removal of memory representations. Previous research has indicated that directed forgetting in working memory reduces the amount of proactive interference for to-be-forgotten memoranda relative to to-be-remembered memoranda. However, it is unknown how directed forgetting within working memory compares to an encode-only condition, in which items are encoded but do not receive a forget cue nor a remember instruction. Here, younger adults (N = 43) performed a working memory directed forgetting task with encode-only trials and a recent probes manipulation to induce proactive interference. Results indicated that (1) proactive interference for encoded-only items did not significantly differ from proactive interference for to-be-remembered items, and (2) proactive interference for to-be-forgotten items was significantly lower than that for both the remember and encode-only conditions. Thus, the present research provides support for the theories that directed forgetting instructions result in differential weakening of targeted memory representations in working memory, and that forget instructions promote goal-directed removal of memory representations. Forget instructions do not simply curtail processing after encoding. This research adds to the understanding of the removal of information from working memory and to the consequences and mechanistic processes of directed forgetting within working memory.

Pre-experimental sleep effects on directed forgetting.

A directed forgetting (DF) paradigm was used to compare the remembering and forgetting of participants with good sleep quality to those with poor sleep quality and the presence of insomnia symptoms. This study implemented a point system in place of remember and forget instructions in a DF task with the goal of computing DF costs and benefits. Relations among memory, sleep, and working memory capacity (WMC) were also examined. DF benefits were observed in both groups, with negative costs found for participants without the presence of insomnia symptoms. WMC was found to be related to memory for positive point items only, and did not differ based on sleep quality. These results suggest that the presence of self-reported insomnia symptoms does not affect performance on a DF task.

Directed forgetting in problem solving

In two experiments, we investigated intentional forgetting of problem-solving routines by adapting the list method of directed forgetting. In Experiment 1, participants practiced solving water-jar problems (Luchins, 1942). After working on a first series of problems that all could be solved by the same formula, one group of participants was instructed to forget the so-far presented items because these, allegedly, had only served as a warm-up, whereas another group did not receive a forget instruction. After practicing a different routine in a second series of problems, participants solved test problems that either could be solved by the formula previously practiced in the first or in the second series of problems. All test problems alternatively could be solved by a more direct formula. The forget instruction significantly reduced the number of test problems solved by the formula of the first series of practice problems. In Experiment 2, participants subsequently practiced two solution formulas in two series of to-be-solved anagrams. Here, a forget instruction regarding the first series of practice anagrams reduced solution speed for test anagrams that had to be solved by the same formula as the to-be-forgotten practice anagrams. Thus, in both experiments, participants relied less on a practiced routine after they had been instructed to intentionally forget the episode of acquiring that routine.

More Is Less: Increased Processing of Unwanted Memories Facilitates Forgetting.

The intention to forget can produce long-lasting effects. This ability has been linked to suppression of both rehearsal and retrieval of unwanted memories, processes mediated by the prefrontal cortex and hippocampus. Here, we describe an alternative account in which the intention to forget is associated with increased engagement with the unwanted information. We used pattern classifiers to decode human functional magnetic resonance imaging data from a task in which male and female participants viewed a series of pictures and were instructed to remember or forget each one. Pictures followed by a forget instruction elicited higher levels of processing in the ventral temporal cortex compared with those followed by a remember instruction. This boost in processing led to more forgetting, particularly for items that showed moderate (vs weak or strong) activation. This result is consistent with the nonmonotonic plasticity hypothesis, which predicts weakening and forgetting of memories that are moderately activated.SIGNIFICANCE STATEMENT The human brain cannot remember everything. Forgetting has a critical role in curating memories and discarding unwanted information. Intentional forgetting has traditionally been linked to passive processes, such as the withdrawal of sustained attention or a stoppage of memory rehearsal. It has also been linked to active suppression of memory processes during encoding and retrieval. Using functional magnetic resonance imaging and machine-learning methods, we show new evidence that intentional forgetting involves an enhancement of memory processing in the sensory cortex to achieve desired forgetting of recent visual experiences. This enhancement temporarily boosts the activation of the memory representation and renders it vulnerable to disruption via homeostatic regulation. Contrary to intuition, deliberate forgetting may involve more rather than less attention to unwanted information.

Selection for encoding: No evidence of better endogenous orienting following forget than following remember instructions.

In an item-method directedforgetting task, attentional resources are withdrawn from forget item processing (e.g., Taylor & Fawcett in Attention, Perception, & Psychophysics, 73, 1790-1814, 2011). Taylor and Hamm (Attention, Perception, & Psychophysics, 78, 168-186, 2016) demonstrated that there is no corresponding increase in the proclivity for exogenous attention to be captured following a forget instruction. This means either that the attentional resources withdrawn from the forget item are reallocated immediately (and therefore not especially vulnerable to capture) or that it is not exogenous attention thatis withdrawn. Given that endogenous attention is distinct from exogenous attention, we therefore extended the Taylor and Hamm study by using endogenous orientingrather than exogenous orienting. Words appeared individually in a peripheral location (Exp. 1) or ina central location (Exp. 2), followed by an instruction to either remember or forget. After a short (50-ms) or long (250-ms) interstimulus interval (ISI), a central cue (80% accurate) directed participants to allocate their attention to the left or right. This was followed by a discrimination target that appeared at a 1,000-ms cue-target stimulus onset asynchrony. A subsequent yes-no recognition test assessed memory for all study items. In both experiments, we observed better recognition of remember wordsthan forget words-a directedforgetting effect. We also found a cueing effect, revealed as faster reaction times to discriminate cued targetsthan to discriminate uncued targets. There was not, however, an effect of memory instruction (and/or instruction-cue ISI) on the magnitude of this cueing effect. Thus, neither exogenous attentionnor endogenous attention remains in an unengaged state following an instruction to forget.

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

In item-method directed forgetting, worse memory performance occurs for to-be-forgotten (TBF) than for to-be-remembered (TBR) items. However, recently TBF items have been found to be recognized more accurately than uninformative (UI) items not associated with any specific task. Here, we compare ERPs elicited by cues signaling the remember or the forget instruction with those elicited by uninformative cues. Participants were presented with a series of complex pictures, each followed by a symbolic TBR, TBF, or UI cue. On a yes-no recognition test, accuracy was higher for TBR than for both TBF and UI items. However, TBF items were recognized more accurately than UI items. ERPs elicited by the TBR cue were larger than ERPs elicited by both TBF and UI cues at the frontal P2, the late frontal negativity, and the late parietal positivity complex. This is consistent with more attention capture, selective rehearsal, and long-term memory encoding of TBR. In contrast, both TBF and UI cues induced a larger frontal N2 than TBR cues. Critically, TBF elicited a larger late right-frontal positivity than both UI and TBR cues and a larger late parietal positivity than UI cues. Moreover, the late right-frontal positivity was correlated with better recognition performance. It may therefore reflect processing orientation rather than inhibition per se. Results suggest that, when compared to UI cues, both TBR and TBF cues are processed actively. Distinct processing is seen at right frontal and centroparietal positive ERPs that may mediate better subsequent recognition of TBF than of UI items.

Successful list-method directed forgetting without retroactive interference of post-instruction learning

ABSTRACTThe focus of the study is the role of interference in list-method directed forgetting. More specifically, our question was whether retroactive interference of the to-be-remembered information is a necessary prerequisite for the directed forgetting effect. In Experiment 1 we used a directed forgetting procedure with one learning list without the interference of any to-be-remembered information. In line with previous results, we did not find a significant directed forgetting effect. Experiment 2 applied a directed forgetting procedure with two study lists, however, the forget instruction was given following the second list. So, List 2 items were designated as to-be-forgotten items, without further learning, whereas List 1 items were to-be-remembered items. The forget instruction selectively decreased the recall of List 2 items, without decreasing the recall performance for List 1. In Experiment 3, using the same procedure with different items, smaller learning lists and reversed output order, we replicated the results of Experiment 2. Altogether, these results point to a flexible, goal-related nature of the directed forgetting phenomenon, showing that some form of interference is a necessary requirement for successful directed forgetting. However, proactive interference of to-be-remembered information in interaction with a forget instruction is suitable for forgetting of subsequently encoded information.

Collaborative remembering revisited: Study context access modulates collaborative inhibition and later benefits for individual memory.

Collaborating groups typically show reduced recall relative to nominal groups, i.e., to the cumulated non-redundant recall of the same number of people remembering in isolation-a finding termed collaborative inhibition. Motivated by the results of several previous studies, this study examined in two experiments whether access to study context at test influences the effects of collaboration. In both experiments, subjects collaborated in triads or recalled previously studied material in isolation. Experiment 1 applied short versus prolonged retention intervals to vary access to study context at test, whereas Experiment 2 used the list-method directed forgetting task and applied remember versus forget instructions to modulate context access. In both experiments, collaborative inhibition was present when access to study context at test was intact (i.e., after the short delay and the remember instruction) but was eliminated when the access was impaired (i.e., after the prolonged delay and the forget instruction). Also, post-collaborative gains for individual recall were greater when context access was impaired and collaborative inhibition was eliminated. The findings demonstrate a critical role of access to study context at test for collaborative inhibition, indicating that impaired context access may reflect a general boundary condition for the recall impairment. The possible role of context reactivation processes for beneficial effects of social recall is discussed.

A neural signature of contextually mediated intentional forgetting.

The mental context in which we experience an event plays a fundamental role in how we organize our memories of an event (e.g. in relation to other events) and, in turn, how we retrieve those memories later. Because we use contextual representations to retrieve information pertaining to our past, processes that alter our representations of context can enhance or diminish our capacity to retrieve particular memories. We designed a functional magnetic resonance imaging (fMRI) experiment to test the hypothesis that people can intentionally forget previously experienced events by changing their mental representations of contextual information associated with those events. We had human participants study two lists of words, manipulating whether they were told to forget (or remember) the first list prior to studying the second list. We used pattern classifiers to track neural patterns that reflected contextual information associated with the first list and found that, consistent with the notion of contextual change, the activation of the first-list contextual representation was lower following a forget instruction than a remember instruction. Further, the magnitude of this neural signature of contextual change was negatively correlated with participants’ abilities to later recall items from the first list.

Instruction to forget lead to emotional devaluation

Objective: The aim of this study was to investigate if the interaction between emotion and memory is bidirectional. Specifically we tested if intentional forgetting of words and faces would lead to their subsequent emotional devaluation. Method: In three experiments we combined an item-method directed forgetting paradigm with an emotional evaluation task. In addition, to test the general response bias hypothesis, we manipulated the forget instruction so that participants would associate a positive encoding affect with this condition. Results: We found that intentionally forgotten words and faces were subsequently emotionally devaluated as compared with the to-be-remembered words and faces. Furthermore, this effect was replicated for words when we associated a positive instruction with the forget condition, which supports that the devaluation was memory specific. Conclusion: These findings suggest that the Distractor Devaluation effect previously reported in the attention field can be generalized to memory. This is one the first studies to show an influence of memory processes, namely forgetting, on emotion.

The representational consequences of intentional forgetting: Impairments to both the probability and fidelity of long-term memory.

We investigated whether intentional forgetting impacts only the likelihood of later retrieval from long-term memory or whether it also impacts the fidelity of those representations that are successfully retrieved. We accomplished this by combining an item-method directed forgetting task with a testing procedure and modeling approach inspired by the delayed-estimation paradigm used in the study of visual short-term memory (STM). or concrete colored images were each followed by a remember (R) or forget (F) instruction and sometimes by a visual probe requiring a speeded detection response (E1–E3). Memory was tested using an old–new (E1–E2) or remember-know-no (E3) recognition task followed by a continuous color judgment task (E2–E3); a final experiment included only the color judgment task (E4). Replicating the existing literature, more “old” or “remember” responses were made to R than F items and RTs to postinstruction visual probes were longer following F than R instructions. Color judgments were more accurate for successfully recognized or recollected R than F items (E2–E3); a mixture model confirmed a decrease to both the probability of retrieving the F items as well as the fidelity of the representation of those F items that were retrieved (E4). We conclude that intentional forgetting is an effortful process that not only reduces the likelihood of successfully encoding an item for later retrieval, but also produces an impoverished memory trace even when those items are retrieved; these findings draw a parallel between the control of memory representations within working and long-term memory.