Recall of mental sleep experience with or without prior verbalization.

We investigated whether verbalization of contents of mental sleep experience (MSE), just after awakening provoked during rapid eye movement (REM) sleep, facilitates subsequent recall in the morning. Twelve subjects were awakened four times in each of two experimental nights and alternately asked to recall, with or without concurrent verbalization, MSE contents preceding the awakening. In the morning, the subjects were asked to report MSEs both verbalized and nonverbalized during the night. If subjects were unable to provide a spontaneous morning report, they were prompted using a probe, which was the title given by the subjects to each MSE at the end of its verbalization or covert recall at night. Frequencies of spontaneous reports were high, regardless of whether MSEs had been previously verbalized or not. The proportions of spontaneous and probed reports were similar for verbalized and nonverbalized MSEs, but spontaneous morning reports were longer than probed ones, regardless of their previous verbalization. Spontaneous and probed morning reports corresponding to night reports shared similar linguistic structures (i.e., length of sentences and proportions of waking-related utterances, which are indicative of difficulty of retrieval for MSE contents) and had similar percentages of contents common to night and morning reports. These findings support the hypothesis that verbalization does not directly influence the further accessibility of MSE contents.     

Blackout of my nights: Contentless,timeless and selfless report from the night in patients with central hypersomnias

At the extreme spectrum of consciousness during sleep, some patients with rare hypersomnias reported experiencing a specific night ‘blackout’ when sleeping, i.e., an absence of experiences or recall of them from sleep onset to offset. Thus, we explored through questionnaires the conscious experiences (dreaming experience, mind, self) during the night in 133 patients with idiopathic hypersomnia, 108 patients with narcolepsy, and 128 healthy controls. The night blackout was more frequent in idiopathic hypersomnia than in narcolepsy and control groups. Patients with idiopathic hypersomnia and frequent night amnesia had lower dream recall frequencies, and felt more often sleep as deep and mind as blank during the night. They had a higher proportion of slow wave sleep on their (retrospectively collected) sleep recordings than those without night blackout. This night blackout provides a new model for studying loss of consciousness during sleep, here as a contentless, selfless and timeless feeling upon awakening.     

Children's recall 1 or 2 years after an event.

In Study 1, children were reinterviewed about an event they had taken part in 2 years earlier when they were 6 years old (M.-E. Pipe & J. C. Wilson, 1994). In Study 2, children were reinterviewed about an event in which they had participated 1 year earlier when they were 6 or 9 years of age (S. Gee & M.-E. Pipe, 1995). Interviews were conducted with or without cue items and distractors, as in the original studies. The amount of information reported in free recall decreased over the 1- or 2-year delays, and for 6-year-olds, there was also a small decrease in accuracy of free recall. Reinstating specific cue items in Study 2 maintained recall when attention was drawn to them, but prompting children led to a decrease in accuracy. Whereas information repeated across interviews was highly accurate, information reported for the first time at the long delays was not.     

Conflict and metacognitive control: the mismatch-monitoring hypothesis of how others' knowledge states affect recall

Information about others' success in remembering is frequently available. For example, students taking an exam may assess its difficulty by monitoring when others turn in their exams. In two experiments, we investigated how rememberers use this information to guide recall. Participants studied paired associates, some semantically related (and thus easier to retrieve) and some unrelated (and thus harder). During a subsequent cued recall test, participants viewed fictive information about an opponent's accuracy on each item. In Experiment 1, participants responded to each cue once before seeing the opponent's performance and once afterwards. Participants reconsidered their responses least often when the opponent's accuracy matched the item difficulty (easy items the opponent recalled, hard items the opponent forgot) and most often when the opponent's accuracy and the item difficulty mismatched. When participants responded only after seeing the opponent's performance (Experiment 2), the same mismatch conditions that led to reconsideration even produced superior recall. These results suggest that rememberers monitor whether others' knowledge states accord or conflict with their own experience, and that this information shifts how they interrogate their memory and what they recall.     

The role of age of acquisition in memory: effects on judgements of learning and recall

Judgements of learning (JOLs) are self-made predictions of the likelihood that one will later recall information. The influence of stimulus characteristics on JOLs and recall continues to receive attention, yet there are still a number of unexplored lexical word features that may exert an effect on mnemonic processing. Using a standard cue-target paradigm, we focused on the role of word age of acquisition (AoA) and evaluated the role of both cue and target AoA on responses. We replicated the robust delayed-JOL effect and used a novel items analysis approach to examine the relationship between intrinsic word features and accuracy and reaction times for both JOLs and recall. A consistent effect of target AoA was found, even after controlling for a range of covariates previously shown to impact JOLs and recall. These results expand the role of AoA in word processing and suggest that it is a key variable in memory and metacognition; they also support Koriat's (1997) cue utilization framework.     

Cue familiarity but not target retrievability enhances feeling-of-knowing judgments.

Two hypotheses concerning people's ability to predict later memory performance for unrecalled items were investigated. The target retrievability hypothesis states that feeling-of-knowing judgments (FKJs) are based on partial target information; and the cue familiarity hypothesis asserts that they are based on recognition of the cues. In Experiments 1 and 2, subjects either generated or read the targets of paired associates. Half of the cues had been primed in a pleasantness-rating task. The generation manipulation increased recall but had no effect on FKJs. Cue priming had no effect on recall but increased FKJs. In Experiment 3, using general information questions, primed after the initial recall attempt, both cue and target priming increased FKJs. Experiment 4, which remedied difficulties in Experiment 3, showed no effect of target priming whereas cue priming increased FKJs. The results favor the cue familiarity hypothesis.     

Les variations dans le rappel onirique : synthèse et intégration des connaissances

The purpose of this review is to identify the main factors influencing dream recall frequency by focussing on the most recent developments and important contributions to the field. In summary, the capacity to produce dream experiences appears to depend on visuospatial skills while the capacity to recall dreams depends primarily on motivational factors as well as on variables affecting the accessibility of the dream experience. With respect to the various traits traditionally associated with dream recall (e.g. absorption, psychological boundaries, mental imagery, creativity), they likely reflect an estimation bias. Finally, the role of the dream experience's saliency on its recall remains uncertain.     

Recalled aspects of original encoding strategies influence episodic feelings of knowing

We tested the hypothesis that the feeling of knowing (FOK) after a failed recall attempt is influenced by recalling aspects of the original encoding strategy. Individuals were instructed to use interactive imagery to encode unrelated word pairs. We manipulated item concreteness (abstract vs. concrete) and item repetitions at study (one vs. three). Participants orally described the mediator produced immediately after studying each item, if any. After a delay, they were given cued recall, made FOK ratings, and attempted to recall their original mediator. Concreteness and item repetition enhanced strategy recall, which had a large effect on FOKs. Controlling on strategy recall reduced the predictive validity of FOKs for recognition memory, indicating that access to the original aspects of encoding influenced FOK accuracy. Confidence judgments (CJs) for correctly recognized items covaried with FOKs, but FOKs did not fully track the strategy recall associations with CJs, suggesting emergent effects of strategy cues that were elicited by recognition tests but not accessed at the time of the FOK judgment. In summary, cue-generated access to aspects of the original encoding strategy strongly influenced episodic FOKs, although other influences were also implicated.     

Forgetting as a function of sleep at different times of day

The experiment studied the separate effects of sleep and time period of retention interval on forgetting. A free recall task was given to independent groups of subjects either at night or in the morning, and a second recall demanded 5 h later, after an intervening period of sleeping or waking activity. Oral body temperatures (BT) were measured at each session. The data were analysed in terms of (a) immediate recall at test 1, and (b) amount forgotten from test 1 to test 2. Immediate recall was higher for morning groups, in agreement with previous findings, serial position analysis indicating that the effect is confined to enhancement of the primary memory component. Long-term retention was higher over the night interval, irrespective of sleeping conditions, though having slept at night produced better retention than having stayed awake. Sleep during the morning was not effective in reducing forgetting. BT showed a marked drop for both night groups and rise for day groups over the retention interval. Alternative explanations for the classical sleep/memory findings are suggested in terms of (a) differential effects of sleep stages on memory, and (b) the underlying diurnal variation in BT and other processes.     

The role of familiarity in episodic memory and metamemory for music

Participants heard music snippets of varying melodic and instrumental familiarity paired with animal-name titles. They then recalled the target when given either the melody or the title as a cue, or they gave name feeling-of-knowing (FOK) ratings. In general, recall for titles was better than it was for melodies, and recall was enhanced with increasing melodic familiarity of both the cues and the targets. Accuracy of FOK ratings, but not magnitude, also increased with increasing familiarity. Although similar ratings were given after melody and title cues, accuracy was better with title cues. Finally, knowledge of the real titles of the familiar music enhanced recall but had, by and large, no effect on the FOK ratings.     

Associative relationships between pre-sleep sentence stimuli and reports of mental sleep experience

The aim of this experiment was to study some linguistic relationships between pre-sleep verbal stimuli and contents of reports of mental experience during sleep. In 4 weekly sessions 16 subjects listened before sleep to a sentence stimulus, which was either semantically acceptable (SEM+) or not (SEM-), and were told to retain it for a recall test after awakening; they were awakened once each night during NREM or REM sleep and asked to report their mental experience during sleep. The relationships between the stimulus and the contents of the reports were classified using Clark's (1970) associative rules. Both pre-sleep sentence stimuli were frequently incorporated into contents of NREM and REM reports, without significant differences between the two types of sleep. The SEM+ sentence led prevalently to incorporations through paradigmatic associative relationships, while the SEM- sentence led to incorporations through both paradigmatic and syntagmatic relationships. It appears that all the features of the lexical constituents of the stimulus may be involved in the processing leading to incorporation.     

Interserial and intraserial interference processes in morning recall of mental sleep experience

This study investigated ways in which predictions from interference theory might explain partial or total failure in the morning recall of mental sleep experience (MSE) episodes reported after provoked night awakening. Interference could take place either between the contents of one MSE episode (intraserial interference) or between the contents of different MSE episodes (interserial interference) and would be more likely to affect morning recall where similar (i.e., interrelated) contents in MSEs are involved. If interference were mainly intraserial, in the morning there would be no change in the difficulty of retrieving interrelated contents, whereas, if it were mainly interserial, there would be increased difficulty in the retrieval of such contents. All the possible pairs of reports obtained by awakening 8 subjects four times in REM sleep during each of four experimental nights spaced at weekly intervals were scored for interrelated contents, using Clark's (1970) system of analysis of paired units, which operates by matching linguistic features. Results showed that interrelations in morning report pairs are as frequent as in night report pairs, maintaining the same linguistic characteristics and with little transfer of contents from one MSE to another. Overall these findings are compatible with the hypothesis that interference is primarily intraserial rather than interserial. It is consequently suggested that morning recall failure may be due to temporary blocking of retrieval.     

The effects of “effort after meaning” on recall: Differences in within- and between-subjects designs

In four experiments, we examined free recall of ambiguous sentences with or without corresponding cues to facilitate comprehension, using Auble and Franks’s (1978) paradigm to examine effort after meaning (Bartlett, 1932). The ambiguous sentences were studied without cues, with cues meaningfully embedded in them, with cues provided shortly before the sentence (precue), or with cues following the sentence after several seconds (delayed cue). When these conditions were manipulated within subjects, the process of cue integration in the pre- and delayed-cue conditions enhanced recall, relative to the no-cue and embedded-cue conditions. Furthermore, in a test condition in which subjects first attempted to recall the cues alone, recall was also best in the delayed-cue condition. The effects described above did not occur when the cue presentation conditions varied between subjects, and on a test of order reconstruction, there was even an advantage for sentences studied in the embedded-cue condition over those studied in the delayed-cue condition. The dissociative effects of experimental design on sentence recall and order reconstruction suggest that effort after meaning might enhance memory for study items at the cost of impairing memory for temporal order information.     

Getting the Picture: Effects of Sketch Plans and Photographs on Children's,Adolescents' and Adults' Eyewitness Recall

We compared the effects of three types of visual aid on free recall across three age groups in an eyewitness paradigm. Child, adolescent and adult participants (N = 144) viewed a short film depicting a non‐violent crime and, following a brief delay, gave a free‐recall account. Participants then described the event once again, with the aid of their own sketch plan, a provided sketch plan or photograph, or with no visual aid. Interviews were transcribed verbatim and coded for the type and accuracy of information reported. Across all age groups, relative to the control condition, all three visual aids increased the amount of new information reported during the second free‐recall account and helped participants to maintain accuracy. All three visual aids therefore had a positive effect on participants' performance; in a forensic setting, however, witnesses' own sketch plans are likely to be the safest, most easily applied and most time effective.Copyright © 2015 John Wiley & Sons, Ltd.     

Memory for movement: Interaction of location and distance cues and imagery ability

The present experiments examined the role of imagery ability in recall of either the terminal location or the distance of a preselected horizontal linear movement following changes in the recall starting position. Subjects were selected on the basis of their scores on a shortened version of the Betts Questionnaire upon Mental Imagery (Betts Q.M.I., Sheehan 1967). Both high and low imagers were assigned to one of four groups, HIL, LIL, HID, LID, the last letter indicating the movement cue (terminal location or distance moved) to be recalled. Recall of the appropriate movement cue from one of four new recall starting positions occurred after either a 5-sec or 30-sec unfilled retention interval. Analysis of constant error indicated all groups were unable to recall the specified movement cue independent of the other source of information, even when subjects were given explicit instructions to utilise an imagery strategy. The data corroborate our earlier findings that memory for self paced movements is based on an interaction of location and distance cues derived from the criterion movement.     

Repetition and trace interaction: Superadditivity

This paper reports five experiments that examined memory for repeated and unrepeated pairs of words. In over 40 experimental comparisons, cued recall of the repeated pairs was better than it would have been if the words had been repeated as independent cognitive events. Therefore, memory traces do interact with other traces of the same nominal items. Our account of superadditive recall is that some encodings fail on the final test because they lack a needed piece of information. Specifically, some need additional item-specific information to enable access by the cue, and some need relational information for recall of the target. The second trial is an implicit test of memory, whose results give the system a heuristic basis for standing pat or doing more encoding. If a retrieved encoding needs less than a new one to become a success, it has a good chance of becoming a success, and recall is superadditive. However, if the ease of retrieving the encoding is for the wrong reasons, such as massed repetition, the item remains a failure, and recall is subadditive.     

Poor recall of eye-movement signals from Stage 2 compared to REM sleep: implications for models of dreaming

An ongoing assumption made by sleep researchers is that since dreams are more often recalled on awakening from rapid eye movement (REM) sleep, dreams must occur more often during this stage of sleep. An alternative hypothesis is that cognition occurs throughout sleep, but the recall of this mentation differs on awakening. When a dream is not reported on awakening, there is no method of establishing whether it did not happen or was forgotten. The aim of the present study was to investigate this issue using an eye movement (EM) signal verification technique. Participants were instructed to produce an EM signal whenever they heard a tone. Tones were presented at increasing volume during Stage 2 and REM sleep until EM signal verification was observed. Ninety seconds after signal verification, participants were awakened and asked if they remembered hearing the tone or responding with the EM signal. Such recollection of signal verified tone (SVT) presentations was significantly less after Stage 2 sleep (65%) compared to REM sleep (100%) presentations. Furthermore, SVT recall was significantly correlated with reported dream recall frequency, suggesting the same processes involved in recalling SVTs might also underlie dream recall.     

Lexical and semantic search in cued recall, fragment completion, perceptual identification, and recognition

Search processes in word-stem cued recall, fragment completion, perceptual identification, and recognition are contrasted. These retention tests involve letters as cues, but the lexical characteristics of these cues vary considerably. In word-stem cued recall, ending letters are presented as recall cues for studied targets (e.g., ONEY as a cue for HONEY). In fragment completion, the test cues consist of letters and spaces (e.g., HO__Y); in perceptual identification, they consist of letter features that survive the mask; and in recognition, they consist of all the letters of the studied word (e.g., HONEY). These differences in retention tests and lexical characteristics were evaluated by manipulating three variables with known effects in cued recall: (a) the presence of study context words emphasizing lexical information, (b) lexical set size corresponding to the number of words that fit the letter cue, and (c) meaning set size corresponding to the number of meaningful associates linked to the studied targets. The results indicated that (a) the presence of study contexts emphasizing lexical information reduced accuracy and response time equally in all tasks, (b) larger lexical set sizes reduced accuracy and response time in all tasks except recognition, and (c) larger meaning set size reduced accuracy in cued recall but not in the other tasks. Lexical search appears to be a significant component process in word-stem cued recall, fragment completion, and identification. Searching through meaning-related concepts encoded during study is a significant component process only in cued recall.     

Individual differences in children's event memory reports and the narrative elaboration technique

Children between 7 and 8 years old took part in a staged event at school and 1 week later were assessed using a short form of the Wechsler Intelligence scale for children (third edition) and measures of metamemory, narrative ability, and socioeconomic status. Two weeks following the event, children either received narrative elaboration training (NET; K.J. Saywitz & L. Snyder, 1996) and were prompted with the four NET cue cards at interview; received verbal prompts corresponding to the cue card categories, but without prior training; or were presented with the cards at interview without prior training. Children given verbal labels as prompts recalled as much information as children who received NET training and cue cards. Measures of intelligence were predictive of amount recalled for cards-only children but not for the other 2 groups, indicating that differences in recall between low- and high-IQ groups were attenuated when recall was supported by NET training or verbal prompting.     

An investigation into the impact of acute stress on encoding in older adults

Acute psychological stress commonly occurs in young and older adults’ lives. Though several studies have examined the influence of stress on how young adults learn new information, the present study is the first to directly examine these effects in older adults. Fifty older adults (M age = 71.9) were subjected to either stress induction or a control task before learning two types of information: a short video and a series of pictures. Twenty-four hours later, they were exposed to misleading information about the video and then completed memory tests for the video and pictures. Heart rate and cortisol measures suggest that a physiological stress response was successfully induced. Though pre-encoding stress had little impact on memory accuracy, stress did influence errors of omission on the cued recall test for the video. Findings are discussed in the context of previous research examining the effects of stress on memory in older adults.