Rumination and intentional forgetting of emotional material

The tendency to respond to negative life events and negative mood states with ruminative thinking has been linked to emotion dysregulation and to a heightened risk for the onset and maintenance of emotional disorders. To further investigate this maladaptive response style, the present study examined whether rumination is linked to individual differences in the ability to intentionally forget emotional material. In a directed forgetting task, participants were instructed to memorise a list of positive and negative words and were subsequently told to forget these words. Next, participants were told to memorise a new list and, finally, recall was tested for all to-be-forgotten and to-be-remembered words. Our results demonstrate a close relation between rumination and recall in the forget condition but not in the remember condition. Specifically, compared to participants who scored low on the Ruminative Responses Scale (RRS), participants who scored high exhibited reduced forgetting of positive and negative to-be-forgotten words. These results remained stable when depression scores were included as a covariate suggesting that irrespective of depressive symptoms, rumination and intentional forgetting of emotional material are closely related.     

Directed forgetting of emotional stimuli in borderline personality disorder

On the basis of clinical literature, the authors hypothesized that individuals with borderline personality disorder (BPD) would show biased information processing when they were exposed to negative affective stimuli of a particular type. Individuals with BPD and controls were tested using a directed forgetting paradigm. Study participants were exposed to 3 types of words (borderline, neutral, positive) and were cued to either remember or forget each word as it was presented. There were no group differences on a free recall task for words in the remember condition. However, participants with BPD recalled significantly more of the borderline words from the forget condition than did controls. In other words, borderline participants remembered borderline words that they were instructed to forget. These results may be consistent with enhanced encoding of salient words and perhaps related themes in BPD individuals.     

Directed forgetting of emotional words

Emotional material may induce processing limitations affecting memory performance. In the present study, the authors investigated how the emotional content of words influences the degree to which participants can be directed to forget them. In Experiment 1, the authors found that negative-valence words were recalled better when participants were told to forget them than when they were told to remember them. This effect was only obtained when a study-list of negative words was presented after the cue to remember or forget the first list. The effect was correlated with negative mood as assessed by the PANAS. Similar results were obtained in Experiment 2, in which the induction of negative arousal by a mild stressor abolished the directed forgetting of words when the following study list was comprised of negative words. These results support the idea that directed forgetting relies on cognitive control processes that may be disrupted by negative emotion.     

Directed forgetting in obsessive-compulsive disorder: replication and extension

Previous research indicates that patients with obsessive-compulsive disorder (OCD) show impaired ability to forget negative material (Behav Res Ther 34 (1996) 633). The present study was intended to replicate and extend these findings by separating emotional valence from personal relevance, using idiographic stimulus selection to control for heterogeneity of OCD concerns, and the addition of an anxious control group. We used a directed forgetting paradigm, in which participants were instructed to either remember or forget a series of words. No differences in impairment were found among the groups during a free recall test, in which they were asked to recall both "remember" and "forget" words. However, during a recognition test, OCD patients showed greater impaired forgetting for OCD-relevant words than did nonanxious and anxious controls. Valence of words did not emerge as a contributing factor to impaired forgetting.     

高低创造性思维水平者定向遗忘效应的差异研究

采用单字法定向遗忘范式,考察远距离联想任务得分高低者在中性和负性词语定向遗忘效应上的差异,来探讨创造性思维水平高低与主动抑制的关系。实验采用2(高/低创造性思维水平)×2(中性/负性词汇)×2(记住/忘记指令)×2(2s/5s时间间隔)混合设计,发现高低创造力组,在材料不同呈现时间下,对不同情绪材料的定向遗忘效应分别不同。低创者在2s和5s以及高创者在5s时间间隔时,均对中性词语表现出定向遗忘效应,而对负性词汇没有表现出明显的定性遗忘效应。高创者在2s时间间隔下,对中性和负性词语均表现出定向遗忘效应。结果表明较短时间内高创者对负性情绪的主动抑制能力优于低创者。     

False memories are hard to inhibit: differential effects of directed forgetting on accurate and false recall in the DRM procedure

Directed forgetting research shows that people can inhibit the retrieval of words that they were previously instructed to forget. The present research applied the directed forgetting procedure to the Deese/Roediger and McDermott (DRM) recall task to determine if directed forgetting instructions have similar or different effects on accurate and false memory. After studying lists of semantically related words, some participants were told to forget those lists, whereas other participants were not. All participants were then shown additional lists to remember. Following study, all participants were asked to free recall as many of the studied words as possible, including those they were previously instructed to forget. Directed forgetting instructions inhibited the accurate recall of studied words, but not the false recall of nonstudied critical words, whether measured by a within-participant or between-participants design. Contrary to an implicit activation hypothesis, false memories survived instructions to forget. These findings were reviewed in terms of fuzzy trace theory and the activation/monitoring approach to false memory.     

Directed forgetting of autobiographical events

Two diary experiments demonstrated directed forgetting (DF) of autobiographical events, previously observed only for less complex memory items. Using a 2-week diary paradigm, we compared recall between a group of participants who were directed to forget Week 1 memories (forget group) and a group who did not receive a forget instruction (remember group). In Experiment 1, the forget group remembered fewer items from Week 1 than did the remember group. The effect was observed for negative and positive valence events, as well as for high and low emotional intensity events. The effect was replicated in Experiment 2 despite a memorable holiday (Valentine's Day) that occurred during the manipulation week. Forget participants remembered fewer low emotional intensity items in Experiment 2. We conclude that intentional forgetting is a plausible explanation for the loss of some autobiographical memories.     

Cognitive load hypothesis of item-method directed forgetting

This study examined the effect of the processing demands of to-be-remembered (TBR) words on item-method directed forgetting. Experiment 1 found that a standard memory group remembered fewer to-be-forgotten (TBF) words than a naming group, in which participants simply named the TBR words during the study phase, even though both groups were equally instructed to forget the TBF words. Experiment 2 manipulated the number of TBR words in the study list, keeping the number of TBF words constant, and found that TBF word forgetting was more difficult in the few TBR words condition than the more TBR words condition. The same pattern was found in the result of Experiment 3 when a cued recall test, instead of a free recall test, was used. In all the experiments, participants were asked to recall the TBF words before the TBR words. These findings are consistent with the cognitive load hypothesis that it is easier to forget when there are fewer cognitive resources available during encoding.     

Cognitive load hypothesis of item-method directed forgetting

This study examined the effect of the processing demands of to-be-remembered (TBR) words on item-method directed forgetting. Experiment 1 found that a standard memory group remembered fewer to-be-forgotten (TBF) words than a naming group, in which participants simply named the TBR words during the study phase, even though both groups were equally instructed to forget the TBF words. Experiment 2 manipulated the number of TBR words in the study list, keeping the number of TBF words constant, and found that TBF word forgetting was more difficult in the few TBR words condition than the more TBR words condition. The same pattern was found in the result of Experiment 3 when a cued recall test, instead of a free recall test, was used. In all the experiments, participants were asked to recall the TBF words before the TBR words. These findings are consistent with the cognitive load hypothesis that it is easier to forget when there are fewer cognitive resources available during encoding.     

Emotional constraints on intentional forgetting

One way people control the contents of their minds is intentional forgetting—voluntarily forgetting events after they have happened. The events people would most like to forget are unpleasant and emotional. This study used a directed forgetting procedure with emotional and neutral pictures to examine whether people can intentionally forget emotional events as easily as mundane ones. When the to-be-forgotten list was neutral, participants showed successful intentional forgetting. But when the to-be-forgotten list was emotional, directed forgetting failed. Results contribute to understanding the ways that emotion constrains mental control by capturing mental processes including memory retrieval. Emotion may short-circuit attempts to forget those parts of the past people would most like to forget.     

The role of forget-cue salience in list-method directed forgetting

Research suggests that manipulating the wording of the forget cue in list-method directed forgetting affects the magnitude of directed forgetting both in younger children (Aslan, Staudigl, Samenieh, & Bauml, in press) and in older adults (Sahakyan, Delaney, & Goodmon, 2008). This occurs when the forget cue overemphasises the importance of forgetting in the current context. The present experiment investigated whether de-emphasising forgetting affected the magnitude of list-method directed forgetting in college adults. Some participants received overt forget cues that explicitly instructed them to forget earlier studied items, whereas others received covert forget cues that implied forgetting by emphasising selective remembering (e.g., "you will only need to remember some of the items"). Results indicated equivalent directed forgetting for both types of cues. However, regardless of the type of cue received, participants who reported using specific forgetting strategies in response to the forget cue showed directed forgetting, whereas those that reported doing nothing did not show any effects. The results underscore that successful directed forgetting requires engagement of controlled processes.     

Directed forgetting of complex pictures in an item method paradigm

An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect—that is, better recognition of “to-be-remembered” than of “to-be-forgotten” pictures—was observed, although its size was smaller than previously reported for words or line drawings. The magnitude of the directed forgetting effect correlated negatively with participants’ depression and dissociation scores. The results indicate that, at least in an item method, directed forgetting occurs for complex pictures as well as words and simple line drawings. Furthermore, people with higher levels of dissociative or depressive symptoms exhibit altered memory encoding patterns.     

Directed forgetting of complex pictures in an item method paradigm

An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect--that is, better recognition of "to-be-remembered" than of "to-be-forgotten" pictures--was observed, although its size was smaller than previously reported for words or line drawings. The magnitude of the directed forgetting effect correlated negatively with participants' depression and dissociation scores. The results indicate that, at least in an item method, directed forgetting occurs for complex pictures as well as words and simple line drawings. Furthermore, people with higher levels of dissociative or depressive symptoms exhibit altered memory encoding patterns.     

Directed forgetting in the list method affects recognition memory for source

The effects of list-method directed forgetting on recognition memory were explored. In Experiment 1 (N = 40), observers were instructed to remember words and their type-cases; in Experiment 2 (N = 80), the instruction was to remember words and their colours. Two lists of 10 words were presented; after the first list, half of the observers (forget) were instructed to forget that list, and the other half (remember) were not given the forget instruction. Recognition of items (words) as well as source (encoding list + case/colour) was measured for forget and remember observers. The forget instruction affected case/colour memory more consistently than item and list memory; a multinomial analysis indicated that source information was affected by the forget instructions. The results indicated that recognition of source information may be a more sensitive indicator of forgetting than recognition of items.     

The role of forget-cue salience in list-method directed forgetting

Research suggests that manipulating the wording of the forget cue in list-method directed forgetting affects the magnitude of directed forgetting both in younger children (Aslan, Staudigl, Samenieh, & Bauml, in press) and in older adults (Sahakyan, Delaney, & Goodmon, 2008). This occurs when the forget cue overemphasises the importance of forgetting in the current context. The present experiment investigated whether de-emphasising forgetting affected the magnitude of list-method directed forgetting in college adults. Some participants received overt forget cues that explicitly instructed them to forget earlier studied items, whereas others received covert forget cues that implied forgetting by emphasising selective remembering (e.g., “you will only need to remember some of the items”). Results indicated equivalent directed forgetting for both types of cues. However, regardless of the type of cue received, participants who reported using specific forgetting strategies in response to the forget cue showed directed forgetting, whereas those that reported doing nothing did not show any effects. The results underscore that successful directed forgetting requires engagement of controlled processes.     

越努力去忘就越能忘记吗？—情绪材料定向遗忘的"剂量效应"

采用项目法定向遗忘研究范式,在两个实验中分别使用情绪性语词和图片材料,考察主观努力程度影响情绪材料定向遗忘的心理机制。研究采用2(语词或图片情绪效价：正词/负词)×2（指示符：记住/忘记)×3（努力程度：20%/60%/100%）的被试内设计,因变量为情绪性语词或图片的再认率和定向遗忘效应。结果表明,正效价词在三种努力程度忘记条件的再认率无差别,而越努力去忘记负效价词,反而越能记住;正负效价的图片材料都呈现出越努力去忘记反而越能记住的特点。以上结果表明,语词与图片分别适合有意识加工和无意识加工,记住指令导致对情绪性语词和图片的选择性复述,符合选择性复述/被动衰退理论,而不同努力程度的忘记指令又引发了对情绪性语词和图片的主动抑制,符合注意抑制/执行控制理论。     

Divided attention facilitates intentional forgetting: evidence from item-method directed forgetting

This study examined the effects of post-cue interval and cognitive load on item-method directed forgetting. The results of Experiment 1 (free recall test) and Experiment 2 (cued recall test) showed that forget item retention increased as the post-cue interval increased. Moreover, increasing the cognitive load of participants by asking them to perform a secondary counting task did not impair, but rather facilitated, the intentional forgetting of the studied item under long post-cue interval conditions. These results and analyses of recall gains from the additional use of the independent cue suggest that the improved recall of forget items caused by an increase in the post-cue interval came from an automatic process, and that after receiving the forget cue, participants did not engage a suppression operation that was resource-demanded. The current findings suggest that forgetting is more effective when participants perform a secondary task after receiving the forget cue.     

Directed forgetting in the list method affects recognition memory for source

The effects of list-method directed forgetting on recognition memory were explored. In Experiment 1 (N = 40), observers were instructed to remember words and their type-cases; in Experiment 2 (N = 80), the instruction was to remember words and their colours. Two lists of 10 words were presented; after the first list, half of the observers (forget) were instructed to forget that list, and the other half (remember) were not given the forget instruction. Recognition of items (words) as well as source (encoding list + case/colour) was measured for forget and remember observers. The forget instruction affected case/colour memory more consistently than item and list memory; a multinomial analysis indicated that source information was affected by the forget instructions. The results indicated that recognition of source information may be a more sensitive indicator of forgetting than recognition of items.     

Impaired directed forgetting in abstinent heroin addicts

Drug-related memories persist long into abstinence and are potent elicitors of drug craving and relapse. We report two experiments examining whether heroin-dependent individuals are impaired in intentionally suppressing drug-related memories. Experiment 1 adopted the Item paradigm where addicts and healthy controls were presented with a list of words each followed by a remember or forget cue. Experiment 2 adopted the List paradigm where they studied one list of items and were then split into a remember group and a forget group. Both groups studied a second list, except that the forget group was told to forget the first list. Compared with controls, addicts showed a reduced directed forgetting effect in the Item method and a total absence of one measure of directed forgetting in the List method (List 2 benefits). Results indicate that heroin addicts are impaired in directed forgetting and that the deficits are likely associated with memory encoding as opposed to retrieval. Possible problems include reduced ability in actively suppressing/stopping encoding of irrelevant information into memory or inability in changing/resetting encoding strategies. In neither experiment did the addicts show any differential directed forgetting effects between drug-related words and neutral words, indicating the generic nature of their intentional forgetting deficits.     

Directed forgetting of a single item

In two experiments, we investigated directed forgetting of a single item. We presented participants with two phone numbers to remember and instructed half of the participants to forget the first phone number. The first number was either learned on a single trial (Experiment 1) or on three trials (Experiment 2). In Experiment 1, there was evidence of directed forgetting as a result of differential encoding; the forget instruction affected recall and recognition for both phone numbers. In Experiment 2, the evidence favored differential rehearsal because the forget instruction affected recall but not recognition. These results indicate that instructions to forget can affect memory of single items.