Collaboration enhances later individual memory for emotional material

Research on collaborative remembering suggests that collaboration hampers group memory (i.e., collaborative inhibition), yet enhances later individual memory. Studies examining collaborative effects on memory for emotional stimuli are scarce, especially concerning later individual memory. In the present study, female undergraduates watched an emotional movie and recalled it either collaboratively (n?=?60) or individually (n?=?60), followed by an individual free recall test and a recognition test. We replicated the standard collaborative inhibition effect. Further, in line with the literature, the collaborative condition displayed better post-collaborative individual memory. More importantly, in post-collaborative free recall, the centrality of the information to the movie plot did not play an important role. Recognition rendered slightly different results. Although collaboration rendered more correct recognition for more central details, it did not enhance recognition of background details. Secondly, the collaborative and individual conditions did not differ with respect to overlap of unique correct items in free recall. Yet, during recognition former collaborators more unanimously endorsed correct answers, as well as errors. Finally, extraversion, neuroticism, social anxiety, and depressive symptoms did not moderate the influence of collaboration on memory. Implications for the fields of forensic and clinical psychology are discussed.     

The word frequency effect in recognition memory versus repetition priming

The role of word frequency in recognition memory and repetition priming was investigated by using a manipulation of attention. In Experiment 1, the lexical decision task produced greater repetition priming for low-frequency words than for high-frequency words following either the attended or the unattended study condition. The recognition memory test, on the other hand, showed a low-frequency word advantage only following the attended study condition. Furthermore, this advantage was limited to the measure of recognition memory based on conscious recollection of the study episode. In Experiment 2, a speeded recognition memory test replicated the pattern obtained with the unspeeded recognition memory test in Experiment 1. These results argue against the view that the word frequency effects in recognition memory and repetition priming have the same origin. Instead, the results suggest that the word frequency effect in recognition memory has its locus in conscious recollection.     

Environmental context and human memory

Five experiments examined the effects of environmental context on recall and recognition. In Experiment 1, variability of input environments produced higher free recall performance than unchanged input environments. Experiment 2 showed improvements in cued recall when storage and test contexts matched, using a paradigm that unconfounded the variables of context mismatching and context change. In Experiment 3, recall of categories and recall of words within a category were better for same-context than different-context recall. In Experiment 4, subjects given identical input conditions showed strong effects of environmental context when given a free recall test, yet showed no main effects of context on a recognition test. The absence of an environmental context effect on recognition was replicated in Experiment 5, using a cued recognition task to control the semantic encodings of test words. In the discussion of these experiments, environmental context is compared with other types of context, and an attempt is made to identify the memory processes influenced by environmental context.     

A test of two different revelation effects using forced-choice recognition

The revelation effect refers to the finding of an increased propensity to classify recognition test probes as old when they are preceded by a problem solving task. Recent research indicates that revelation effects are dissociable based on whether the revelation task involves an item that is the same as or different than the subsequently presented recognition probe. Using a two-alternative forced-choice design, we found a revelation effect for both words (Experiment 1) and nonwords (Experiment 2) in the condition where the revealed item was the same as the target item (same revelation condition), but no effect when the revealed item was different than either test alternative (different revelation condition). These results were replicated using a mixed list design containing both words and nonwords (Experiment 3). Results support Verde and Rotello’s (2004) two-factor account of the revelation effect, which proposes that changes in memory sensitivity underlie revelation effects in the same revelation condition, and that changes in the decision criterion are responsible in the different revelation condition.     

Collaboration and prospective memory: comparing nominal and collaborative group performance in strangers and couples

To perform prospective memory (PM) tasks in day-to-day life, we often enlist the help of others. Yet the effects of collaboration on PM are largely unknown. Adopting the methodology of the “collaborative recall paradigm”, we tested whether stranger dyads (Experiment 1) and intimate couples (Experiment 2) would perform better on a “Virtual Week” task when working together or each working separately. In Experiment 1, we found evidence of collaborative inhibition: collaborating strangers did not perform to their pooled individual potential, although the effect was modulated by PM task difficulty. We also found that the overall collaborative inhibition effect was attributable to both the retrospective and prospective components of PM. In Experiment 2 however, there was no collaborative inhibition: there was no significant difference in performance between couples working together or separately. Our findings suggest potential costs of collaboration to PM. Intimate relationships may reduce the usual costs of collaboration, with implications for intervention training programmes and for populations who most need PM support.     

Conversation memory: the effects of speaker status on memory for the assertiveness of conversation remarks

We conducted three experiments to examine the effects of information about a speaker's status on memory for the assertiveness of his or her remarks. Subjects either read (Experiments 1 and 2) or listened to a conversation (Experiment 3) and were later tested for their memory of the target speaker's remarks with either a recognition (Experiment 1) or a recall procedure (Experiments 2 and 3). In all experiments the target speaker's ostensible status was manipulated. In Experiment 1, subjects who believed the speaker was high in status were less able later to distinguish between remarks from the conversation and assertive paraphrases of those remarks. This result was replicated in Experiment 2, but only when the status information was provided before subjects read the conversation and not when the information was provided after the conversation had been read. Experiment 2's results eliminate a reconstructive memory interpretation and suggest that information about a speaker's status affects the encoding of remarks. Experiment 3 examined this effect in a more ecologically representative context.     

The effects of amount of processing on recall and recognition

Johnson-Laird, Gibbs and de Mowbray (1978) and Ross (1981) have argued that amount of processing, as indexed by the overall number of decisions a subject makes, provides a good predictor of incidental memory performance. Conversely, McClelland, Rawles and Sinclair (1981) have provided evidence that it is normally the number of positive decisions rather than the overall number of decisions per se that determines level of recall. The present study replicated and extended the findings of McClelland and his colleagues. In free recall (Experiment 1 and 3), cued recall (Experiment 3) and recognition in the presence or absence of context cues (Experiments 2 and 3), an account based on number of positive decisions provided by far the better explanation. Experiment 3 also revealed that the experimental manipulations had a somewhat greater effect on recall than recognition. This is explained in terms of Tulving and Pearlstone's (1966) distinction between availability and accessibility. It is suggested that words associated with negative decisions are not only less accessible in memory, there are also fewer of them available for recall and recognition.     

Food delivery as a conditional stimulus: Feature-learning and memory in pigeons

Three experiments investigated the learning and memory of discriminations based on presence versus absence of a pre-trial food delivery. In Experiment 1 half the illuminations of a response key were followed by food regardless of the subject's behavior. In one group an extra food delivery preceded only reinforced trials (feature-positive condition), whereas in a second group it preceded only nonreinforced trials (feature-negative condition). Key pecks and approaches revealed more rapid and superior discrimination learning in the first group. Experiment 2 replicated the results of Experiment 1 but yielded no evidence that greater “unexpectedness” of pretrial food conditions facilitates discriminative performance. In Experiment 3, individual pigeons trained on a conditional discrimination exhibited a within-subject feature-positive superiority. Delay between pretrial and trial stimuli interacted with feature-positive versus feature-negative training in both the between-group (Experiment 2) and within-subject (Experiment 3) procedures: performance was decremented at both short and long delays in the feature-positive condition but was decremented only at longer delays in the feature-negative condition. The feature-positive superiority obtained here is incompatible with explanations based on either the general concept of “perceptual organization” or on the conditional nature of feature-negative discriminations.     

Effects of repeated collaborative retrieval on individual memory vary as a function of recall versus recognition tasks

Our research examines how prior group collaboration modulates later individual memory. We recently showed that repeated collaborative recall sessions benefit later individual recall more than a single collaborative recall session (Blumen & Rajaram, 2008). Current research compared the effects of repeated collaborative recall and repeated collaborative recognition on later individual recall and later individual recognition. A total of 192 participants studied a list of nouns and then completed three successive retrieval sessions in one of four conditions. While two collaborative recall sessions and two collaborative recognition sessions generated comparable levels of individual recall (CRecall-CRecall-I Recall ～ CRecognition-CRecognition-I Recall , Experiment 1a), two collaborative recognition sessions generated greater levels of individual recognition than two collaborative recall sessions (CRecognition-CRecognition- IRecognition > CRecall-CRecall- I Recognition , Experiment 1b). These findings are discussed in terms of two opposing mechanisms that operate during collaborative retrieval—re-exposure and retrieval disruption—and in terms of transfer-appropriate processing across collaborative and individual retrieval sessions.     

Mutual inhibition in collaborative recall: evidence for a retrieval-based account

In Experiment 1 participants gave 3 successive free recalls of items learned either individually or in pairwise collaboration. The first and third recalls were performed individually, the second alone or in collaboration. Collaborative recall led to an inhibitory effect after individual learning but not after collaborative learning, in which partners had similar retrieval strategies. Consistent with a retrieval locus for collaborative inhibition, non-recalled items reappeared in subsequent individual recall. Experiment 2 showed that collaborative inhibition was eliminated when a separate retrieval cue was given for each item. Experiments 2 and 3 also showed that when participants learned items in the same order, their retrieval strategies were more similar and they showed less collaborative inhibition. It is concluded that mutual interference in collaborative recall is due to the mutual disruption of individual retrieval strategies.     

Typicality and familiarity of faces

We examined context-free familiarity information as a source of the effects of face typicality upon face recognition. Experiment 1 tested memory for typical and unusual faces by (1) subjects who received an input list followed immediately by a recognition test (standard condition), (2) subjects who viewed all test faces (targets and lures) prior to the input list (prefamiliarization condition), and (3) subjects who viewed all test faces after the input list but prior to recognition (postfamiliarization condition). Although false-alarm errors in the standard condition were lower for unusual than for typical faces, this effect was reduced by postfamiliarization and was eliminated entirely by prefamiliarization. The prefamiliarization and typicality effects were replicated in Experiment 2, which showed that patterns of old judgments were compatible with the hypothesis that, although familiarity of new faces is greater if these faces are typical, the increment in familiarity that results from presentation is greater if these faces are unusual.     

Recognition memory for tactile sequences.

In three experiments participants were required to compare the similarity in item order for two temporally separated sequences of tactile stimuli presented to the fingers of the hand. Between-sequence articulatory suppression but not tactile interference impaired recognition accuracy (Experiment 1), and the null effect of tactile interference was not due to the second tactile sequence overwriting the sensory record of the first sequence (Experiment 2). Experiment 3 showed that compared to a condition where the second sequence was presented in the tactile modality only, recognition was enhanced when the second sequence was seen presented either to the hand or on a diagrammatic representation of a hand. A final experiment showed that the effects of Experiment 1 were replicated when the underside of the forearm was used for stimulus presentation, suggesting that the data are not idiosyncratic to the first method of presentation. The pattern of results suggests memory for a sequence of tactile stimuli involves the deployment of strategies utilising a combination of verbal rehearsal and visuo-spatial recoding rather than relying solely on the retention of sensory traces. This is taken to reflect limitations in both the capacity and duration of tactile sensory memory.     

Working memory load differentially affects tip-of-the-tongue states and feeling-of-knowing judgments

Tip-of-the-tongue states (TOTs) are judgments of the likelihood of imminent retrieval for items currently not recalled, whereas feeling-of-knowing judgments (FOKs) are predictions of successful recognition for items not recalled. The assumption has been that similar metacognitive processes dictate these similar judgments. In Experiment 1, TOTs and FOKs were compared for general information questions. Participants remembered four digits (working memory load) during target retrieval for half of the questions, and there was no memory load for the other questions. Working memory did not affect recall but decreased the number of TOTs and increased FOKs. In Experiment 2, participants maintained six digits during retrieval. TOTs decreased in the working memory condition, but FOKs remained constant. Experiment 3 replicated the results of Experiment 2 while asking for FOKs for recall. In each of the first three experiments, positive metacognitive judgments also affected working memory performance, supporting the idea that working memory and metamemory use similar monitoring processes. In Experiment 4, visual working memory did not affect TOTs or FOKs. The data support a view that TOTs and FOKs are separable metacognitive entities.     

Effects of pair collaboration and word-frequency in recognition memory: a study with the remember-know procedure

The present study investigated the effects of pair collaboration and word-frequency on recognition memory, using the "remember-know" procedure. The aim was to test the predictions of the information-exchange hypothesis (Clark, Hori, Putnam & Martin, 2000), which states that collaborative facilitation occurs when participants are able to share their recollective memories with other members of the group. Results showed that recognition performance was significantly better in the collaborative than in the individual condition, and better for low-frequency than for high-frequency words. The advantage of collaborating dyads was produced by an increase of correct hits, coupled with a significant reduction of false alarms. Furthermore, the analysis of the "remember" (R) and "know" (K) responses indicated that the effects of both pair collaboration and word-frequency were larger on recollection than on familiarity processes. It is concluded that, in a collaborative condition, arguments based on the retrieval of the contextual details associated with the target words are more effective than those based on familiarity in increasing the proportions of correct hits. In addition, it is proposed that collaboration may lead to a reduction of the probability to accept new items on the basis of familiarity (K) responses.     

The effects of collaboration on recall of social information

Three experiments examined the effects of passage type on both individual and collaborative memory performance. In Experiment 1, both individuals and collaborative groups recalled more information from passages containing social information than non-social information. Furthermore, collaborative inhibition (CI) was observed for both types of passages. In Experiment 2, which included a social passage that did not contain gossip, significant main effects of both gossip (gossip > non-gossip) and sociability (explicit > implicit) were observed. As in Experiment 1, CI was observed across all conditions. Experiment 3 separately manipulated gossip and the interest level of the passages and both of these factors enhanced memory performance. Moreover, robust CI was again observed across all conditions. Taken together, the present results demonstrate a mnemonic benefit for social information in individuals and collaborative groups.     

When two is too many: Collaborative encoding impairs memory

Humans routinely encode and retrieve experiences in interactive, collaborative contexts. Yet much of what we know about human memory comes from research on individuals working in isolation. Some recent research has examined collaboration during retrieval, but not much is known about how collaboration during encoding affects memory. We examined this issue. Participants created episodes by elaborating on study materials alone or collaboratively, and they later performed a cued-recall task alone, with the study partner, or with a different partner (Experiment 1). Collaborative encoding impaired recall. This counterintuitive outcome was found for both individual and group recall, even when the same partners collaborated across encoding and retrieval. This impairment was significantly reduced, but persisted, when the encoding instructions encouraged free-flowing collaboration (Experiment 2). Thus, the collaborative-encoding deficit is robust in nature and likely occurs because collaborative encoding produces less effective cues for later retrieval.     

Net effect of memory collaboration: How is collaboration affected by factors such as friendship,gender and age?

The purpose of the study was to investigate explicit spatial and verbal collaborative memory performance. Factors such as friendship, age and gender were chosen for ecological and theoretical reasons. In Experiment 1 friendship and age were studied. The task was to retrieve the location of 25 pictures, which were presented in a 5 x 5-matrix grid. All participants retrieved once individually and once dyadically. Dyads were compared to the predicted base line, i.e., the pooled score from two participants working on their own (the same participants as in the dyad). Based on cognitive development aspects and collaboration data, it was predicted that the young collaborating dyads would not be able to reduce the net negative effects of collaboration to the same extent as older dyads. The findings revealed that, (1) dyadic collaboration affected spatial memory performance negatively, i.e., net negative effects of collaboration; (2) older (15-years-old), as opposed to young (7-years-old) dyads, reduced the net negative effects of collaboration and; (3) friend dyads, regardless of age, were able to reduce the net negative effect. In experiment 2, gender differences were studied in two explicit memory tasks. The purpose was to investigate if earlier findings of collaboration can be generalised to another ecological aspect of group composition, i.e., gender. Gender differences were studied at individual and group level. The results suggest that gender related memory differences exist on an individual and dyadic level in terms of absolute scores. Women remember explicit memory tasks to a greater degree than men. No main effect was found for gender in collaboration, i.e., both genders suffered compared to predicted potential.     

成员关系对协作提取成绩的影响

当人们与搭档组成社会群体一起协作讨论某些已经发生的事件或经验时, 该社会群体中的成员关系对协作提取成绩的影响仍不明确。本研究通过两项实验, 分别使用语词词单和情景故事作为实验材料, 考察成员关系(包括关系类型和关系时长)对协作提取成绩的影响。研究结果表明, 当记忆的材料为语词词单时, 青年陌生组出现了协作抑制; 而当记忆的材料为情景故事时, 青年夫妻和老年夫妻组均出现了协作促进。此外, 老年夫妻在协作提取情景故事的过程中使用的有效交流策略更多, 且这些有效交流策略的使用与更高的协作提取成绩有关。该结果支持了具有长时亲密关系的老年夫妻之间的“交互记忆系统”对协作促进的关键作用, 为理解成员关系对协作提取成绩的影响提供了全面的证据。     

Effect of post-encoding emotion on recollection and familiarity for pictures

Although prior studies have examined the effect of post-encoding emotional arousal on recognition memory for words, it is unknown whether the enhancement effect observed on words generalizes to pictures. Furthermore, prior studies using words have showed that the effect of emotional arousal can be modulated by stimuli valence and delay in emotion induction, but it is unclear whether such modulation can extend to pictures and whether other factors such as encoding method (incidental vs. intentional encoding) can be modulatory. Five experiments were conducted to answer these questions. In Experiment 1, participants encoded a list of neutral and negative pictures and then watched a 3-min neutral or negative video. The delayed test showed that negative arousal impaired recollection regardless of picture valence but had no effect on familiarity. Experiment 2 replicated the above findings. Experiment 3 was similar to Experiment 1 except that participants watched a 3-min neutral, negative, or positive video and conducted free recall before the recognition test. Unlike the prior two experiments, the impairment effect of negative arousal disappeared. Experiment 4, where the free recall task was eliminated, replicated the results from Experiment 3. Experiment 5 replicated Experiments 1 and 2 and further showed that the impairment effects of negative arousal could be modulated by delay in emotion induction but not by encoding method or stimuli valence. Taken together, the current study suggests that the enhancement effect observed on words may not generalize to pictures.     

Age differences in collaborative memory: the role of retrieval manipulations

In two experiments, we examined age differences in collaborative inhibition (reduced recall in pairs of people, relative to pooled individuals) across repeated retrieval attempts. Younger and older adults studied categorized word lists and were then given two consecutive recall tests and a recognition test. On the first recall test, the subjects were given free-report cued recall or forced-report cued recall instructions (Experiment 1) or free recall instructions (Experiment 2) and recalled the lists either alone or in collaboration with another subject of the same age group. Free-report cued recall and free recall instructions warned the subjects not to guess, whereas forcedreport cued recall instructions required them to guess. Collaborative inhibition was obtained for both younger and older adults on initial tests of free-report cued recall, forced-report cued recall, and free recall, showing that the effect generalizes across several tests for both younger and older adults. Collaborative inhibition did not persist on subsequent individual recall or recognition tests for list items. Older adults consistently falsely recalled and recognized items more than did younger adults, as had been found in previous studies. In addition, prior collaboration may exaggerate older adults’ tendency toward higher false alarms on a subsequent recognition test, but only after a free recall test. The results provide generality to the phenomenon of collaborative inhibition and can be explained by invoking concepts of strategy disruption and source monitoring.