Metacognition influences item-method directed forgetting

In 4 experiments, we examined whether metacognitive beliefs about item memorability influence item-method directed forgetting. In Experiment 1, participants studied loud and quiet items, which were subsequently cued as to-be-remembered (TBR) or to-be-forgotten (TBF). Typically, the volume of stimuli does not influence recall, although loud items are judged as more memorable than quiet items (Rhodes & Castel, 2009). In contrast, we found a recall advantage for loud items in directed forgetting, although this was observed for TBR items but not TBF items. The loud item advantage disappeared in Experiment 2, when we eliminated all TBF trials and instead inserted additional trials during which participants could engage in extra rehearsal of earlier presented items. In Experiments 3 and 4, a recall advantage for loud items was observed again when items were assigned a mixture of positive and negative values, but it did not emerge when items were assigned graded positive values. Overall, the results showed that the recall advantage for loud items emerges only in response to the need to forget some items. We propose 2 mechanisms to account for these results-either participants select to rehearse loud items as a controlled strategy that allows them to forget some items, or they have an unconscious preference for loud items that emerges only in response to the need to forget. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

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.     

Decomposing item-method directed forgetting of emotional pictures: Equivalent costs and no benefits

Using an item-method directed forgetting task, we presented negative, neutral, and positive photographic pictures, one at a time, each followed by an instruction to remember or forget. We determined that the directed forgetting effect, defined as better subsequent recognition of to-be-remembered (TBR) items than to-be-forgotten (TBF) items, was equivalent across negative, neutral, and positive pictures. To disentangle the underlying costs (i.e., decrease in memory for TBF items) and benefits (i.e., increase in memory for TBR items), we compared recognition memory performance in the directed forgetting task to that of a novel within-subjects remember-all control condition (Experiment 1) and to a between-subjects remember-all control group (Experiment 2). We observed costs without benefits across all three emotions—negative, neutral, and positive—in both experiments. These results demonstrate that equivalent directed forgetting effects for emotional stimuli are not attributable to different underlying component processes. Instead, our results suggest that selection for encoding is accomplished in similar ways, regardless of emotional content.     

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.     

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.     

In support of selective rehearsal: Double-item presentation in item-method directed forgetting

Psychonomic Bulletin & Review - Despite the substantial evidence highlighting the role of selective rehearsal in item-method directed forgetting, recent work has suggested that forgetting may...     

Forgetting is effortful: Evidence from reaction time probes in an item-method directed forgetting task

Reaction time (RT) was measured in response to visual detection probes embedded within an item-method directed forgetting paradigm. In Experiment 1, study words were presented individually followed by an instruction to remember (R) or forget (F). Probes were presented at stimulus onset asynchronies (SOAs) of 1,400, 1,800, or 2,600 msec in relation to the study word or memory instruction. After the study trials, a yes-no recognition task measured retention of R and F words. Experiment 2 added a no-word control condition and no-probe catch trials. In both experiments, post-F probe RTs were longer than post-R probe RTs at early SOAs. Confirming that participants attended to the memory instructions, there was a significant directed forgetting effect, with greater recognition of R than of F words. These findings contradict the view that directed forgetting in the item-method paradigm is due to the passive decay of nonrehearsed F items; instead, they are consistent with the view that intentional forgetting in an item-method paradigm occurs via the operation of an active, potentially inhibitory, cognitive process.     

A salient distractor does not disrupt conjunction search

Leading theories of attention posit that bottom-up and top-down factors simultaneously affect attentional priority in visual search. Recent evidence, however, suggests that subjects may rely exclusively on top-down guidance when searching for a target defined by a specific known feature (Bacon & Egeth, 1994). In the present experiment, we addressed this issue in a conjunction search task. We investigated how searching for a green O among green Ts and red Os is affected by the presence of a distractor with a unique shape (green X), color (blue O), or both (blue X). We showed that the salient distractor does not disrupt performance on target-present trials, but produces a large interference on target-absent trials. We conclude that salience-based and top-down processes are alternative modes of guidance, rather than joint contributors in the allocation of attentional priority.     

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).     

Time does not cause forgetting in short-term serial recall

Time-based theories expect memory performance to decline as the delay between study and recall of an item increases. The assumption of time-based forgetting, central to many models of serial recall, underpins their key behaviors. Here we compare the predictions of time-based and event-based models by simulation and test them in two experiments using a novel manipulation of the delay between study and retrieval. Participants were trained, via corrective feedback, to recall at different speeds, thus varying total recall time from 6 to 10 sec. In the first experiment, participants used the keyboard to enter their responses but had to repeat a word (called the suppressor) aloud during recall to prevent rehearsal. In the second experiment, articulation was again required, but recall was verbal and was paced by the number of repetitions of the suppressor in between retrieval of items. In both experiments, serial position curves for all retrieval speeds overlapped, and output time had little or no effect. Comparative evaluation of a time-based and an event-based model confirmed that these results present a particular challenge to time-based approaches. We conclude that output interference, rather than output time, is critical in serial recall.     

Angry faces are more resistant to forgetting than are happy faces: directed forgetting effects on the identity of emotional faces

Using the item-method directed forgetting paradigm (i.e. intentionally forgetting specified information), we examined directed forgetting of facial identity as a function of facial expression and the sex of the expresser and perceiver. Participants were presented with happy and angry male and female faces cued for either forgetting or remembering, and were then asked to recognise previously studied faces from among a series of neutral faces. For each recognised test face, participants also recalled the face’s previously displayed emotional expression. We found that angry faces were more resistant to forgetting than were happy faces. Furthermore, angry expressions on male faces and happy expressions on female faces were recognised and recalled better than vice versa. Signal detection analyses revealed that male faces gave rise to a greater sensitivity than female faces did, and male participants, but not female participants, showed greater sensitivity to male faces than to female faces. Several theoretical implications are discussed.     

Increasing stimulus intensity does not affect sensorimotor synchronization

When people synchronize taps with isochronously presented stimuli, taps usually precede the pacing stimuli [negative mean asynchrony (NMA)]. One explanation of NMA [sensory accumulation model (SAM), Aschersleben in Brain Cogn 48:66–79, 2002] is that more time is needed to generate a central code for kinesthetic-tactile information than for auditory or visual stimuli. The SAM predicts that raising the intensity of the pacing stimuli shortens the time for their sensory accumulation, thereby increasing NMA. This prediction was tested by asking participants to synchronize finger force pulses with target isochronous stimuli with various intensities. In addition, participants performed a simple reaction-time task, for comparison. Higher intensity led to shorter reaction times. However, intensity manipulation did not affect NMA in the synchronization task. This finding is not consistent with the predictions based on the SAM. Discrepancies in sensitivity to stimulus intensity between sensorimotor synchronization and reaction-time tasks point to the involvement of different timing mechanisms in these two tasks.     

Providing corrective feedback during retrieval practice does not increase retrieval-induced forgetting

Recalling a subset of studied materials can impair subsequent retrieval of related, nontested materials. In two experiments, we examined the influence of providing corrective feedback (no feedback, immediate feedback, delayed feedback) during retrieval practice on this retrieval-induced forgetting effect. Performance was assessed with category cued recall (e.g., recall all exemplars studied under Weather), category-and-stem cued recall (e.g., Weather–B___), and recognition. We report a dissociation between the effects of feedback on memory of the tested materials and the nontested materials. Whereas providing immediate or delayed feedback (compared to no feedback) improved recall and recognition of the tested items, it had no influence on retrieval-induced forgetting. These results are consistent with the inhibition account of retrieval-induced forgetting. From an applied perspective, this finding is encouraging for students and educators who use testing to foster learning.     

Remembering the good, forgetting the bad: intentional forgetting of emotional material in depression

The authors examined intentional forgetting of negative material in depression. Participants were instructed to not think about emotional nouns that they had learned to associate with a neutral cue word. The authors provided participants with multiple occasions to suppress the unwanted words. Overall, depressed participants successfully forgot negative words. Moreover, the authors obtained a clear practice effect. However, forgetting came at a cost: Compared with the nondepressed participants and with the depressed participants who were instructed to forget positive words, depressed participants who were instructed to forget negative words showed significantly worse recall of the baseline words. These results indicate that training depressed individuals in intentional forgetting could prove to be an effective strategy to counteract automatic ruminative tendencies and mood-congruent biases.     

Recognition-induced forgetting does not occur for temporally grouped objects unless they are semantically related

Recent evidence has shown that practice recognizing certain objects hurts memories of objects from the same category, a phenomenon called recognition-induced forgetting. In all previous studies of this effect, the objects have been related by semantic category (e.g., instances of vases). However, the relationship between objects in many real-world visual situations stresses temporal grouping rather than semantic relations (e.g., a weapon and getaway car at a crime scene), and temporal grouping is thought to cluster items in models of long-term memory. The goal of the present study was to determine whether temporally grouped objects suffer recognition-induced forgetting. To this end, we implemented a modified recognition-induced forgetting paradigm in which the objects were temporally clustered at study. Across four experiments, we found that recognition-induced forgetting occurred only when the temporally clustered objects were also semantically related. We conclude by discussing how these findings relate to real-world vision and inform models of memory.     

Categorical perception of emotional facial expressions does not require lexical categories

Does our perception of others' emotional signals depend on the language we speak or is our perception the same regardless of language and culture? It is well established that human emotional facial expressions are perceived categorically by viewers, but whether this is driven by perceptual or linguistic mechanisms is debated. We report an investigation into the perception of emotional facial expressions, comparing German speakers to native speakers of Yucatec Maya, a language with no lexical labels that distinguish disgust from anger. In a free naming task, speakers of German, but not Yucatec Maya, made lexical distinctions between disgust and anger. However, in a delayed match-to-sample task, both groups perceived emotional facial expressions of these and other emotions categorically. The magnitude of this effect was equivalent across the language groups, as well as across emotion continua with and without lexical distinctions. Our results show that the perception of affective signals is not driven by lexical labels, instead lending support to accounts of emotions as a set of biologically evolved mechanisms.     

Lesions in the anterior thalamic nuclei of rats do not disrupt acquisition of stimulus sequence learning

Four experiments examined the effects of encoding multiple standards in a temporal generalization task in the visual and auditory modalities both singly and cross-modally, using stimulus durations ranging, across different experiments, from 100 to 1,400 ms. Previous work has shown that encoding and storing multiple auditory standards of different durations resulted in systematic interference with the memory of the standard, characterized by a shift in the location of peak responding, and this result, from Ogden, Wearden, and Jones (2008), was replicated in the present Experiment 1. Experiment 2 employed the basic procedure of Ogden et al. using visual stimuli and found that encoding multiple visual standards did not lead to performance deterioration or any evidence of systematic interference between the standards. Experiments 3 and 4 examined potential cross-modal interference. When two standards of different modalities and durations were encoded and stored together there was also no evidence of interference between the two. Taken together, these results, and those of Ogden et al., suggest that, in humans, visual temporal reference memory may be more permanent than auditory reference memory and that auditory temporal information and visual temporal information do not mutually interfere in reference memory.     

Directed forgetting between,but not within,dissociative personality states

To investigate amnesia between identities in dissociative identity disorder (DID), the authors assessed explicit and implicit memory performance on a directed-forgetting task in 12 DID patients who switched from one state to an "amnesic" state between presentation and memory testing. DID patients were instructed either to remember or to forget neutral and emotional words. Besides an overall decrease in explicit memory, patients demonstrated selective forgetting of to-be-forgotten, but not of to-be-remembered words in the amnesic state. Patients did not exhibit any directed forgetting within the same state. Implicit memory was fully preserved across states. Independent of state, patients recalled more emotional than neutral information. These results may extend the conceptualization of memory processes in DID, suggesting an important role for retrieval inhibition.     

Superior modulation of activation levels of stimulus representations does not underlie superior discrimination in autism

The performance of children with and without autism was compared in object-based positive and negative priming tasks within a visual search procedure. Object-based positive and negative priming effects were found in both groups of children. This result provides the first evidence for the activation of object-based representations during visual search task performance and further supports the notion that both excitatory and inhibitory guidance mechanisms are involved in target location in visual search. The children with autism were overall better than the typically developing children at visual search, thus replicating demonstrations of superior discrimination in autism. Furthermore, there was no difference between the magnitude of the positive nor the negative priming effects of the groups. This finding suggests that excitatory and inhibitory control operate comparably in autism and normal development. These results are discussed in the light of the superior ability of individuals with autism to discriminate between items. More specifically, it is argued that superior discrimination in autism does not result from enhanced top-down excitatory and inhibitory control.     

Intentional forgetting can increase,not decrease,residual influences of to-be-forgotten information

Intentionally forgotten information remains in memory at essentially full strength, as measured by recognition and priming, but access to that information is impaired, as measured by recall. Given that pattern, it seemed plausible that intentionally forgotten information might have a greater impact on certain subsequent judgments than would intentionally remembered information. In 2 experiments, participants cued to forget nonfamous names were subsequently more likely to make false attributions of fame to those names than were participants instructed to remember them. These findings implicate retrieval inhibition as a potent factor in the interplay of recollection and priming in memory and judgment. They also point to possible unintended consequences of instructions to forget, suppress, or disregard in legal or social settings.