Language facilitates event memory in early childhood: Child comprehension,adult-provided linguistic support and delayed recall at 16 months

Adult-provided supportive language facilitates memory for the past in preverbal and verbal children. Work conducted with 18-month-olds indicates that children benefit from supportive adult language when tested after a 4-week delay but not when tested immediately after sequence demonstration; moreover, findings reveal that supportive language provided only at test may be more facilitative of recall after a delay relative to supportive language provided only at encoding. In the present study, we examined whether child language comprehension abilities moderated the extent to which preverbal children benefitted from supportive language provided at encoding and test. The findings indicated that child language comprehension and supportive language provided at encoding were unassociated with performance at baseline or immediate imitation; however, the moderating effect of child language comprehension on adult-provided supportive language at encoding and test was observed after a 1-week delay. Correlations revealed continuous associations between general comprehension scores and recall performance after the 1-week delay on sequences presented in the most supportive condition at encoding. Taken together, the presented findings reveal that the complex interplay between language and cognition is established in early childhood, with foundational relations emerging before children are capable of verbally reporting on the past.     

Episodic memory reconsolidation: Updating or source confusion?

Reactivation of apparently stable, long-term memory can render it fragile, and dependent on a re-stabilisation process referred to as “reconsolidation”. Recently we provided the first demonstration of reconsolidation effects in human episodic memory (Hupbach, Gomez, Hardt, & Nadel, 2007 Hupbach, A., Gomez, R., Hardt, O. and Nadel, L. 2007. Reconsolidation of episodic memories: A subtle reminder triggers integration of new information. Learning & Memory, 14: 47–53. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Hupbach, Hardt, Gomez, & Nadel, 2008 Hupbach, A., Hardt, O., Gomez, R. and Nadel, L. 2008. The dynamics of memory context-dependent updating. Learning & Memory, 15: 574–579.  [Google Scholar]). Memory for a set of objects was modified by the presentation of a new set, if and only if participants were reminded of the first learning episode before learning the new set. The present study asks whether this effect can be interpreted as a source discrimination problem; i.e., participants have difficulties remembering which objects were presented during which session, and do not actually incorporate new objects into the reactivated memory. The present study used a recognition test and asked participants directly about the source of their memories. Participants in the no-reminder group showed very few source errors. Participants in the reminder group misattributed the source of objects from the second set as being from the first set but not vice versa, thus demonstrating updating of the original memory. This finding is informative with respect to the misinformation paradigm, and reconsolidation is discussed as a possible mechanism underlying our results and the misinformation effect.     

Memory conjunction errors: The effects of presentation duration and study repetition

The memory-strengthening manipulations of increased presentation duration and increased number of times items were presented were manipulated in the memory conjunction paradigm. Participants viewed parent words once or three times during the study portion of the experiment for 250 ms, 1000 ms, or 3000 ms. After an old/new recognition test participants were asked to give explanations for their answers from the recognition test. The results of true and false recognition as well as recall-to-reject responses (e.g., I know I did not see blackbird since I saw blackmail) indicated that both familiarity and recollection were influenced by the memory-strengthening manipulations. The results provide evidence for dual-process theories of recognition memory and the opposing processes of familiarity and recollection.     

Don't it make my brown eyes blue: Co-witness misinformation about a target's appearance can impair target-absent line-up performance

Misinformation from another witness has been shown to impair eyewitness reports, but little is known about how it may influence eyewitness identification. In Experiment 1, adult pairs comprising one participant and one experimental confederate viewed a video clip of a staged theft. Half of the participants were then misinformed by the confederate that the thief's accomplice had blue eyes (in fact, they were brown). Next, individual participants described the accomplice and completed a target-absent photographic line-up task comprising blue-eyed members. Misinformed participants were several times more likely than controls to describe the accomplice as having blue eyes, and twice as likely to identify someone from the line-up. In Experiment 2, when line-up members’ eye colour was digitally altered from blue to brown, the line-up effect disappeared, suggesting that the increase in identifications in Experiment 1 was not a generalised increase in willingness to choose from the line-up. In Experiment 3, we discounted the possibility that discussion alone could account for the line-up misinformation effect, by subjecting all participants to co-witness discussion.     

Phenomenological characteristics of emotional memories in younger and older adults

Older adults sometimes show a “positivity effect” in memory, remembering proportionally more positive information than younger adults. Using a modified Memory Characteristics Questionnaire, this study examined whether emotional valence impacts the phenomenological qualities of young and older adults’ memories. Ageing did not impact the effect of valence on the qualities of high-arousal memories. However, ageing sometimes impacted subjective memory for details of low-arousal memories: In Experiment 2, older adults reported remembering more thoughts, feelings, and temporal order details about positive low-arousal stimuli, while young adults’ ratings for those dimensions were higher for negative low-arousal stimuli. These findings suggest that valence most readily affects the qualities of young and older adults’ emotional memories when those memories are low in arousal.     

Investigating the variability of memory distortion for an analogue trauma

In this paper, we examine whether source monitoring (SM) errors might be one mechanism that accounts for traumatic memory distortion. Participants watched a traumatic film with some critical (crux) and non-critical (non-crux) scenes removed. Twenty-four hours later, they completed a memory test. To increase the likelihood participants would notice the film's gaps, we inserted visual static for the length of each missing scene. We then added manipulations designed to affect people's SM behaviour. To encourage systematic SM, before watching the film, we warned half the participants that we had removed some scenes. To encourage heuristic SM some participants also saw labels describing the missing scenes. Adding static highlighting, the missing scenes did not affect false recognition of those missing scenes. However, a warning decreased, while labels increased, participants' false recognition rates. We conclude that manipulations designed to affect SM behaviour also affect the degree of memory distortion in our paradigm.     

Islands of memory: Autobiographical remembering in amnestics

In amnestics with anterograde amnesia, memories of post-onset autobiographical experiences, if present at all, are typically barren and impoverished. However, there have been sporadic reports of islands of memory—memories that are vivid, detailed, and specific to time and place. The aim of this study was to verify the presence of such memories and examine their incidence rate. Anterograde amnestics were interviewed in their home using a narrative interviewing strategy with a view to describing memory in everyday life. Each autobiographical memory of a post-onset event was coded for quantity-length, and quality-episodicity. In just over half of the amnestics (8 out of 14), a memory that was lengthy, rich in personal details, and localisable was recollected. The quantitative and qualitative aspects of these island memories were significantly different from the other autobiographical memories that the amnestics supplied. These memories were at odds with what would be expected on the basis of their performance on standardised memory instruments. Our findings suggest there is occasionally more variability in remembering of autobiographical experiences in some amnestics than has traditionally been believed.     

Recall-to-reject: The effect of category cues on false recognition

Four experiments examined the effect of category cueing on recall-to-reject, one of the central memory-editing mechanisms thought to prevent the occurrence of false memories. When category names were used as retrieval cues, the typically observed false recognition effect was eliminated for semantically associated distractors (Experiment 1a) and, moreover, a reduction in the absolute level of the false alarm rate was found for phonologically associated distractors (Experiment 2a). In addition to the old/new-recognition data, analyses using multinomial models support the interpretation that category cueing was successful in increasing the probability of recall-to-reject (Experiments 1b and 2b). The results are in line with dual-process theories of recognition memory and provide further evidence for recall-to-reject in single item recognition. They demonstrate its potential to reduce false recognition even when explicit instructions are not given. In addition, the results demonstrate that the paradigm can give rise to side effects that oppose recall-to-reject. A simultaneous familiarity increase can explain why many studies failed to find evidence for recall-to-reject in terms of false alarm rates.     

Collaborative memory and part-set cueing impairments: The role of executive depletion in modulating retrieval disruption

When people are exposed to a subset of previously studied list items they recall fewer of the remaining items compared to a condition where none of the studied items is provided during recall. This occurs both when the subset of items is provided by the experimenter (i.e., the part-set cueing deficit in individual recall) and when they are provided during the course of a collaborative discussion (i.e., the collaborative inhibition effect in group recall). Previous research has identified retrieval disruption as a common mechanism underlying both effects; however, less is known about the factors that may make individuals susceptible to such retrieval disruption. In the current studies we tested one candidate factor: executive control. Using an executive depletion paradigm we directly manipulated an individual's level of executive control during retrieval. Results revealed no direct role of executive depletion in modulating retrieval disruption. In contrast, executive control abilities were indirectly related to retrieval disruption through their influence at encoding. Together these results suggest that executive control des not directly affect retrieval disruption at the retrieval stage, and that the role of this putative mechanism may be limited to the encoding stage.