The role of source memory in older adults' recollective experience

Younger adults' "remember" judgments are accompanied by better memory for the source of an item than "know" judgments. Furthermore, remember judgments are not merely associated with better memory for individual source features but also with bound memory for multiple source features. However, older adults, independent of their subjective memory experience, are generally less likely to "bind" source features to an item and to each other in memory (i.e., the associative deficit). In two experiments, we tested whether memory for perceptual source features, independently or bound, is also the basis for older adults' remember responses or if their associative deficit leads them to base their responses on other types of information. The results suggest that retrieval of perceptual source features, individually or bound, forms the basis for younger but not for older adults' remember judgments even when the overall level of memory for perceptual sources is closely equated (Experiment 1) and when attention is explicitly directed to the source information at encoding (Experiment 2).     

Attention and recollective experience in recognition memory

The functional relation between recognition memory and conscious awareness was assessed in an experiment in which undivided attention at study was compared with two divided attention conditions, one more demanding than the other. When recognizing a word from the study list, subjects indicated whether they could consciously recollect its prior occurrence or recognized it on some other basis, in the absence of conscious recollection. Divided attention at study progressively impaired word recognition accompanied by conscious recollection. Recognition in the absence of conscious recollection was not affected by divided attention. These findings are interpreted as providing further support for the idea that recognition memory entails two distinct components, one based on associative and contextual information, the other based on a "traceless" awareness of familiarity.     

Cognitive effort and recollective experience in recognition memory

The difficulty of the cognitive operations required to process study items was manipulated in two experiments investigating recollective experience. In subsequent recognition tests, subjects indicated whether their recognition judgements for items processed in these tasks were based on recollection ("remember" responses) or on familiarity ("know" responses). In Experiment 1 target items were presented in the context of a category decision task. It was found that remember responses increased with the difficulty of the category decision. For positive instances, remember responses were greater for items of low instance frequency than for items of high instance frequency, while for negative instances remember responses were greater for items from similar categories than for items from dissimilar categories. These effects were not present in know responses. In Experiment 2, remember responses were more frequent when study items had been presented in the form of anagrams to be solved than when they had been presented in the form of words to be read aloud. The incidence of know responses was not affected by the format in which study items were presented. Source judgements were also more accurate when recognition was based on recollection. It is argued that the type of conscious awareness experienced during recognition is determined by the knowledge activated by items presented in the recognition test, which in turn is determined by the nature of the operations engaged at encoding.     

Forgetting in recognition memory with and without recollective experience

Retention interval was manipulated in two recognition-memory experiments in which subjects indicated when recognizing a word whether its recognition was accompanied by some recollective experience ("remember") or whether it was recognized on the basis of familiarity without any recollective experience ("know"). Experiment 1 showed that between 10 min and 1 week, "remember" responses declined sharply from an initially higher level, whereas "know" responses remained relatively unchanged. Experiment 2 showed that between 1 week and 6 months, both kinds of responses declined at a similar, gradual rate and that despite quite low levels of performance after 6 months, both kinds of responses still gave rise to accurate discrimination between target words and lures. These findings are discussed in relationship to current ideas about multiple memory systems and processing accounts of explicit and implicit measures of retention.     

Developmental changes in memory source monitoring.

Previous research suggests that children are more likely than adults to confuse memories of actions they imagined themselves performing with memories of actions they actually performed (Realization Judgments), but are not more likely to confuse memories of actions they had imagined performing with memories of actions they saw another person perform (Reality Monitoring). We approach these findings in terms of a theory about the processes by which people identify the sources of their recollections (Source Monitoring). This approach suggests that children may be more likely than adults to confuse memories from different sources whenever the sources are highly similar to one another. Experiments 1 and 2 tested this hypothesis by manipulating the perceptual and semantic similarity of two sources of information and testing 4- and 6-year-old and adult subjects' recollection of the sources of particular pieces of information. Experiment 3 tested the hypothesis that children are more likely than adults to mistakenly identify memories of things they imagined another person doing as memories of things they witnessed that person doing. The findings indicate that (a) people are more likely to confuse memories from similar than dissimilar sources, (b) source monitoring improves during the preschool and childhood years, and (c) children may be especially vulnerable to the effects of source similarity.     

Mediators of age-related differences in recollective experience in recognition memory

This study examined states of awareness with the Remember/Know paradigm during verbal recognition memory in young and old adults. Following the presentation of a word list, subjects undertook a recognition test and indicated whether they could consciously recollect its prior occurrence (R) or recognize it on some other basis, without conscious recollection (K). In this individual-difference approach we also incorporated various processing-speed and working-memory measures to study the link between aging, states of awareness and processing resources. The results revealed that, compared to younger adults, older adults exhibited a decline in the amount of R responses during the recognition test whereas the amount of K responses did not change. Structural equation modeling indicated that a slower processing speed associated with a limited working-memory capacity is a key to explaining age-related variance in conscious recollection. The findings offer further support for the distinction between remembering and knowing and for the processing-resources hypothesis of aging.     

Differential time-dependent effects of emotion on recollective experience and memory for contextual information

Emotion has been suggested to slow forgetting via a mechanism that enhances memory consolidation. Here, we investigate whether this time dependent process influences the subjective experience of recollection as well as the ability to retrieve specific contextual details of the study event. To do so we examined recognition for emotional and neutral pictures at two retention intervals and collected remember/know reports and reports about the task that had been performed with the item during encoding. Recollective experience was enhanced for emotional compared to neutral photos after a 24-h delay, but not immediately after encoding. In contrast, memory for the task performed during encoding did not differ between emotional and neutral photos at either time point. The findings indicate that emotion slows the effects of forgetting on the recollective experience associated with studied events, without necessarily slowing the forgetting of specific contextual details of those events.     

Expertise and recollective experience: recognition memory for familiar and unfamiliar academic subjects

Two experiments investigated whether expertise effects in recognition memory could be found for different academic subjects. The roles of subjective experience and repetition on such effects were also explored. Experiment 1 showed that overall recognition memory was greater for familiar than for unfamiliar academic words (the expertise effect). Additionally, this effect was attributable to the subjective experience of remembering rather than knowing. Experiment 2 showed that repetition of stimulus items at study eliminated these expertise effects. Previous research has generally failed to find expertise effects in overall recognition memory. The present findings show that expertise effects do occur in overall recognition memory and are associated with the richer memorial experience of remembering rather than knowing. Copyright © 2005 John Wiley & Sons, Ltd.     

Long-term memory for performed and observed actions: Retrieval awareness and source monitoring

The self-performed task (SPT) paradigm was employed to investigate incidental memory for action events, focusing on states of awareness at retrieval (Remembering–Knowing) and source monitoring in performed and observed actions, at delays of 1 and 2 weeks. Recognition was better for performed than observed actions, but this effect was visible only after 1 week of retention. Conversely, observed actions were associated with better source memory at both delays. When the source was correctly identified, performed and observed actions were accompanied by equal proportions of Remember judgements. However, when source monitoring was incorrect, performed actions were more frequently associated with a feeling of re-experiencing the original event, thus suggesting an enactment-related recollective superiority, although secondary to the availability of reliable contextual information.     

Long-term memory for performed and observed actions: retrieval awareness and source monitoring

The self-performed task (SPT) paradigm was employed to investigate incidental memory for action events, focusing on states of awareness at retrieval (Remembering-Knowing) and source monitoring in performed and observed actions, at delays of 1 and 2 weeks. Recognition was better for performed than observed actions, but this effect was visible only after 1 week of retention. Conversely, observed actions were associated with better source memory at both delays. When the source was correctly identified, performed and observed actions were accompanied by equal proportions of Remember judgements. However, when source monitoring was incorrect, performed actions were more frequently associated with a feeling of re-experiencing the original event, thus suggesting an enactment-related recollective superiority, although secondary to the availability of reliable contextual information.     

A comparison of item and source forgetting

The purpose of the present research was to compare memory for an item with memory for the item’s source. Experiment 1 investigated discrimination between two external sources: each item in a list of words was spoken in either a male or a female voice. Subjects received a test of item recognition and a test of source monitoring at each of four delay intervals (immediate, 30 min, 48 h, 1 week). In contrast with previous research, no evidence of differential forgetting rates for item and source information was found. With delay intervals of 0 and 48 h, Experiment 2 replicated Experiment 1 while adding a reality monitoring condition that required discrimination between an internal (i.e., self-generated) and an external source. Subjects were better at making internal-external discriminations than at making external-external discriminations, but both types of source monitoring declined at the same rate as memory for the items themselves.     

The effects of interacting in repeated events on children's eyewitness memory and source monitoring

Accurate eyewitness memory of an event may be affected by exposure to and degree of involvement with other related events. In this study, we investigated whether interacting in a related video event affected children's accounts of a real-life target event, and whether interacting in the target event affected memory for different details within the target event. Four-, 6-, and 9-year-old children interacted with an adult who made a puppet. Half of the children in each age group also interacted with a video of a similar event (interactive condition) and half sat and watched the video without interacting (watch condition). When asked non-misleading questions a week later, children in the interactive condition confused the two events more than those in the watch condition. The 4-year-olds in the interactive condition reported a higher rate of confusions in free recall than the 4-year-olds in the watch condition. There were no effects of interaction on responses to misleading questions. The 6- and 9-year-olds were more accurate at answering questions related to actions they themselves had performed than actions performed by the experimenter, although this pattern was reversed for the 4-year-olds. The results are discussed in terms of children's eyewitness memory. © 1998 John Wiley & Sons, Ltd.     

A neuropsychological study of fact memory and source amnesia

We investigated the ability of amnesic patients to learn new facts (e.g., Angel Falls is located in Venezuela) and also to remember where and when the facts were learned (i.e., source memory). To assess the susceptibility of fact and source memory to retrograde amnesia, patients prescribed electroconvulsive therapy were presented facts prior to the first treatment and were tested after their second treatment. All amnesic patients exhibited marked fact memory impairment. In addition, some amnesic patients exhibited source amnesia (i.e., they recalled a few facts but then could not remember where or when those facts had been learned). Source amnesia was unrelated to the severity of the memory deficit itself, because patients who exhibited source amnesia recalled as many facts as the patients who did not. These results show that the deficit in amnesia includes an impairment in acquiring and retaining new facts. Source amnesia can also occur, but it is dissociable from impaired recall and recognition and appears to reflect difficulty in remembering the specific context in which information is acquired. The findings are discussed in terms of their significance for how memory is organized.     

Neuroimaging evidence for agenda-dependent monitoring of different features during short-term source memory tests

A short-term source monitoring procedure with functional magnetic resonance imaging assessed neural activity when participants made judgments about the format of 1 of 4 studied items (picture, word), the encoding task performed (cost, place), or whether an item was old or new. The results support findings from long-term memory studies showing that left anterior ventrolateral prefrontal cortex (PFC) is engaged when people make source attributions about reflectively generated information (cognitive operations, conceptual features). The findings also point to a role for right lateral PFC in attention to perceptual features and/or familiarity in making source decisions. Activity in posterior regions also differed depending on what was evaluated. These results provide neuroimaging evidence for theoretical approaches emphasizing that agendas influence which features are monitored during remembering (e.g., M. K. Johnson, S. Hashtroudi, & D. S. Lindsay, 1993). They also support the hypothesis that some of the activity in left lateral PFC and posterior regions associated with remembering specific information is not unique to long-term memory but rather is associated with agenda-driven source monitoring processes common to working memory and long-term memory.     

The self and recollective experience

Three experiments investigated the hypothesis that self-reference at encoding increases the probability of recollective experience in recognition memory. In all three experiments separate groups of subjects studied words naming personality traits. One group judged the self-relevance of the traits, the other groups performed orientating tasks low in self-reference. In a recognition test subjects first identified old items and then indicated which of these were accompanied by recollective experience ('remember' responses) and which were recognized on some other basis ('know' responses). No reliable differences in overall recognition performance between self-referent and semantic encoding tasks were observed. However, subjects who encoded trait adjectives with reference to the self produced reliably more remember responses and few know responses than subjects who had encoded the items in the low self-referent tasks. Experiment 1 demonstrated a self-reference effect in recognition accompanied by recollective experience after 1-hour retention interval, while Experiment 2 found this effect to persist over a 24-hour retention interval. Experiment 3 demonstrated that this self-reference effect is obtained under incidental as well as under intentional learning conditions. Taken together these findings demonstrate the importance of self-reference as a factor in determining the likelihood that recognition judgements will be accompanied by recollective experience.     

Functional aspects of recollective experience

The functional relationship between recognition memory and conscious awareness was examined in two experiments in which subjects indicated when recognizing a word whether or not they could consciously recollect its prior occurrence in the study list. Both levels of processing and generation effects were found to occur only for recognition accompanied by conscious recollection. Recognition in the absence of conscious recollection, although less likely, was generally reliable and uninfluenced by encoding conditions. These results are consistent with dual-process theories of recognition, which assume that recognition and priming in implicit memory have a common component. And they strengthen the case for making a functional distinction between episodic memory and other memory systems.     

Adapting a memory framework (source monitoring) to the study of closure processes

The present experiments adapt a memory framework (source monitoring) to the study of closure processes. Closure processes are invoked as explanatory mechanisms underlying the ability to identify objects under conditions of incomplete visual information. If closure processes are activated, filling in missing pieces of visual information, intriguing memory predictions follow. When making source judgments about the way in which visual information was experienced initially (e.g., complete or incomplete in form), a particular kind of memory error should be evident. Incomplete visual information should be remembered as complete in form, and indeed, this error is observed. The present experiments test alternative interpretations for the initial reports of this memory error in the context of a search task modeled after the Where's Waldo? children's books. The effects of several new factors (e.g., familiarity) are reported, and alternative interpretations for the bias to report complete are eliminated. Findings, therefore, have implications for understanding the mechanisms of closure processes, as well as for the source-monitoring framework itself.     

A comparison of involuntary autobiographical memory retrievals

This study compared three different ways autobiographical memories are elicited involuntarily: (1) cued by an active goal common to memory and retrieval contexts in combination with sensory information associated with this goal‐directed activity; (2) cued by sensory information that does not relate to goal‐directed activity common to both memory and retrieval contexts; and (3) activated when no identifiable cue present in retrieval context. Two hundred and twenty eight participants recorded details of a single autobiographical memory that resulted naturally from a spontaneous, non‐deliberate retrieval. Nearly all recorded memories described specific events (83%) with very few memories less than 7 days old (8%) and many memories more than 5 years old (44%). No significant differences resulted between the three retrieval types for the age, specificity or prior rehearsal of memories reported. However, the level of attention at retrieval was significantly more diffuse for retrievals without a clearly identifiable cue. The authors discuss the implications of these findings for current models of involuntary autobiographical memory retrieval. Copyright © 2006 John Wiley & Sons, Ltd.     

Overdistribution in source memory

Semantic false memories are confounded with a second type of error, overdistribution, in which items are attributed to contradictory episodic states. Overdistribution errors have proved to be more common than false memories when the 2 are disentangled. We investigated whether overdistribution is prevalent in another classic false memory paradigm: source monitoring. It is. Conventional false memory responses (source misattributions) were predominantly overdistribution errors, but unlike semantic false memory, overdistribution also accounted for more than half of true memory responses (correct source attributions). Experimental control of overdistribution was achieved via a series of manipulations that affected either recollection of contextual details or item memory (concreteness, frequency, list order, number of presentation contexts, and individual differences in verbatim memory). A theoretical model was used to analyze the data (conjoint process dissociation) that predicts that (a) overdistribution is directly proportional to item memory but inversely proportional to recollection and (b) item memory is not a necessary precondition for recollection of contextual details. The results were consistent with both predictions.