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.     

Knowing but not remembering: Adult age differences in recollective experience

Age differences in recollective experience were examined in two experiments in which younger and older adults used their self-generated associations as retrieval cues. When recalling an item, subjects indicated whether they consciously remembered its prior occurrence, or merely knew that it was presented previously. The results of both experiments showed that aging selectively impaired retention accompanied by recollective experience, as measured byremember responses, but had no effects in the absence of recollective experience, as measured byknow responses. In Experiment 2, a similar pattern of data was obtained for a group of younger adults by increasing the rate of presentation at study. The results also indicated that judgments of recollective experience were related to type of encoding: Subjects who generated detailed associations reported higher levels of remember responses and lower levels of know responses than did subjects who generated fewer detailed associations. The results are discussed in terms of processes related to perceptual familiarity and contextual detail.     

Components of recollective experience in cued recall

Components of recollective experience were examined in relation to cue effectiveness by presenting subjects with their own or someone else's associations as retrieval cues. When recalling an item, subjects indicated whether they consciously recollected its prior occurrence ("remembering") or recalled it on some other basis, in the absence of conscious recollection ("knowing"). The results showed that cue compatibility (self-generated vs. someone else's cues) and retention interval (immediate vs. delayed test) selectively impaired retention accompanied by recollective experience, as measured by remember responses, but had reduced effects in the absence of recollective experience, as measured by know responses. The results are discussed in terms of variables dissociating judgments of recollective experience.     

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.     

What underlies the deficit in reported recollective experience in old age?

In recognition memory, older adults report fewer occasions on which recognition is accompanied by recollection of the original encoding context. This study asks why this occurs. Two main hypotheses were tested: (1) Older adults fail to encode the items sufficiently when first they experience them. (2) Older adults have a retrieval deficit that prevents efficient reintegration of target and context. In addition, the hypothesis that frontal lobe integrity is essential for recollective experience was examined. Twenty older (mean age 70.7 years) and 20 younger (mean age 22.9 years) adults were asked to study a list of items and to verbalize the strategies they were using to remember. A further 20 older adults (mean age 70.0 years) were tested without the think-aloud protocol. Subsequently, subjects completed a battery of psychometric tests before completing a recognition test. As expected, older adults showed less recollective experience. They differed from the young in how they encoded the material, and once this difference was accounted for, no age differences in recollective experience remained. There was little evidence to support the hypothesis that frontal lobe integrity plays a role in the reduction of recollective experience with age.     

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.     

Recognition memory in amnesia: effects of relaxing response criteria

In two experiments, using the remember/know paradigm, we examined whether recognition memory in amnesic patients can be improved by instructing patients to relax their response criterion. Experiment 1 was modeled after a study by Dorfman, Kihlstrom, Cork, and Misiaszek (1995), in which direct instructions to respond more leniently led to an increase in recognition accuracy in patients with ECT-induced amnesia. We failed to extend this finding to patients with global amnesia, but the manipulation was unsuccessful in control subjects as well. In Experiment 2, response criterion was manipulated indirectly by providing information about the alleged base rate of study items on the recognition test. This manipulation led to a criterion shift in control subjects and enhanced discriminability in amnesic patients. Analysis of “remember” and “know” responses suggests that improved accuracy in amnesia was associated with enhanced familiarity-based recognition.     

Recognition memory and awareness: A large effect of study-test modalities on “know” responses following a highly perceptual orienting task

Abstract

Two experiments investigated the effects of varying the correspondence between presentation and test modes on states of conscious awareness in recognition memory. Experiment 1 used visual test items and showed that auditory and visual study modes differentially affected recollective experience and feelings of familiarity assessed by “remember” and “know” responses accompanying recognition: “know” responses were slightly enhanced following visual presentation, but this was largely offset by a similarly small increase in “remember” responses. Experiment 2 employed conditions designed to maximise any effect on “know” responses of the correspondence between presentation and test modes by using a highly perceptual orienting task at study. Under these conditions, there was a large mode correspondence effect on “know” responses. The results support the idea that “know” responses are particularly sensitive to perceptual factors.     

Aging,source memory,and the experience of “remembering”

In a previous study, we found source memory for perceptual features to differentiate between younger but not older adults’ reports of recollective (“remember”; R) and “know” (K) experiences. In two experiments with younger (17–30 years) and older (64–81 years) participants, we examined whether memory for meaningful speaker sources would accompany older adults’ recollective experience. Indeed, memory for male and female speakers (but not partial memory for gender; Experiment 1) as well as bound memory for speakers and their facial expressions (Experiment 2) distinguished between both younger and older adults’ RK reports. Thus, memory for some sources forms a common basis for younger and older adults’ retrieval experience. Nonetheless, older adults still showed lower objective source memory and lower subjective source-attribution confidence than younger adults when reporting recollective experiences, suggesting that source memory is less relevant to their retrieval experience than for younger adults.     

Gaze control and recollective experience in face recognition

In two experiments, we examined the relation between gaze control and recollective experience in the context of face recognition. In Experiment 1, participants studied a series of faces, while their eye movements were eliminated either during study or test, or both. Subsequently, they made remember/know judgements for each recognized test face. The preclusion of eye movements impaired explicit recollection without affecting familiarity-based recognition. In Experiment 2, participants examined unfamiliar faces under two study conditions (similarity vs. difference judgements), while their eye movements were registered. Similarity vs. difference judgements produced the opposite effects on remember/know responses, with no systematic effects on eye movements. However, face recollection was related to eye movements, so that remember responses were associated with more frequent refixations than know responses. These findings suggest that saccadic eye movements mediate the nature of recollective experience, and that explicit recollection reflects a greater consistency between study and test fixations than familiarity-based face recognition.     

The influence of decision criteria upon remembering and knowing in recognition memory.

One may recognise an item as 'old' on basis of a recollective experience or by a feeling of familiarity without specific recollection. The former is called a 'remember' judgement; the latter a 'know' judgement. It has been claimed that remember and know responses reflect qualitatively distinct components of recognition memory, and not just derive from gradual differences in perceived trace strength or subjective certainty (i.e. remember judgments include memories of which one is more confident). Nonetheless, the present study examined the possibility that the distinction does relate to decision criteria placed upon a single familiarity axis (see Donaldson, 1996; Hirshman & Master, 1997). To this purpose, two groups of subjects were compared: one, which was instructed to be very conservative in their old-new judgements, while the other group was stimulated to be very lenient instead. Remember hit rates increased with more lenient criteria, whereas know hit rates did not, but false alarm rates did. While remember sensitivity was equal in the two groups, know sensitivity was lower with liberal criteria. Also it correlated with overall response bias. This lends support to the possibility that subjects not only apply an old-new decision criterion, but also set a remember-know criterion, which is affected in a similar way by liberal versus conservative instructions.     

On interpreting the relationship between remember–know judgments and confidence: The role of instructions

Two experiments were designed to test the hypothesis that the nature of the remember–know instructions given to participants influences whether these responses reflect different memory states or different degrees of memory confidence. Participants studied words and nonwords, a variable that has been shown to dissociate confidence from remember–know judgments and were given a set of published remember–know instructions that either emphasized know judgments as highly confident (Experiment 1) or as less confident (Experiment 2) states of recognition. Experiment 1 replicated the standard finding showing that remembering and knowing were differently influenced by the word–nonword variable, whereas confidence responses were not. By contrast, Experiment 2 showed a similar pattern of data for remember–know and sure–unsure responses, thus demonstrating the importance of the instructions for interpreting the relationship between remembering and knowing and confidence.     

Remembering and knowing: Two means of access to the personal past

The nature of recollective experience was examined in a recognition memory task. Subjects gave “remember” judgments to recognized items that were accompanied by conscious recollection and “know” judgments to items that were recognized on some other basis. Although a levels-of-processing effect (Experiment 1) and a picture-superiority effect (Experiment 2) were obtained for overall recognition, these effects occurred only for “remember” judgments, and were reversed for “know” judgments. In Experiment 3, targets and lures were either preceded by a masked repetition of their own presentation (thought to increase perceptual fluency) or of an unrelated word. The effect of perceptual fluency was obtained for overall recogrntion and “know” judgments but not for “remember” judgments. The data obtained for confidencejudgments using the same design (Experiment4) indicated that “remember”/”know” judgments are not made solely on the basis of confidence. These data support the two-factor theories of recognition memory by dissociating two forms of recognition, and shed light on the nature of conscious recollection.     

Mine to remember: The impact of ownership on recollective experience

Evaluating information with reference to self is associated with enhanced memory, the “self-reference effect”. The effect is found in recognition accompanied by recollective experience (remembering), but not in recognition based on a feeling of knowing. The current research employed an ownership procedure to investigate whether less evaluative forms of self-referential cognition produce similar enhancement of recollective experience. Participants were asked to sort items into baskets that belonged to themselves or a fictitious other. A subsequent remember–know recognition test showed that items encoded in the context of self-ownership were more likely to be correctly recognized than other-owned items. This ownership effect was found in remember, but not know, responses. This finding suggests that creating a self-referential encoding context leads to elaborative representations in episodic memory, even in the absence of explicit self-evaluation.     

Processing speed, executive function, and age differences in remembering and knowing.

A group of young (n = 52, M = 23.27 years) and old (n = 52, M = 68.62 years) adults studied two lists of semantically unrelated nouns. For one list a time of 2 s was allowed for encoding, and for the other, 5 s. A recognition test followed where participants classified their responses according to Gardiner's (1988) remember-know procedure. Age differences for remembering and knowing were minimal in the faster 2-s encoding condition. However, in the longer 5-s encoding condition, younger persons produced significantly more remember responses, and older adults a greater number of know responses. This dissociation suggests that in the longer encoding condition, younger adults utilized a greater level of elaborative rehearsal governed by executive processes, whereas older persons employed maintenance rehearsal involving short-term memory. Statistical control procedures, however, found that independent measures of processing speed accounted for age differences in remembering and knowing and that independent measures of executive control had little influence. The findings are discussed in the light of contrasting theoretical accounts of recollective experience in old age.     

Distinguishing states of awareness from confidence during retrieval: evidence from amnesia

Two experiments were conducted to determine whether recollective experience is distinguishable from confidence. In Experiment 1, we tested college participants in a within-subjects design and replicated Gardiner and Java's (1990) findings from a between-subjects design. We observed higher remember judgments for words than for nonwords, but higher know judgments for nonwords than for words. For confidence judgments, we obtained greater sure than unsure responses for both words and nonwords. In Experiment 2, we tested amnesic participants and matched control participants. Control participants produced the same pattern of results as college participants, but the results of amnesic participants diverged in an important way. For confidence judgments, the amnesic participants, like the control and college participants, made more sure than unsure judgments to both words and nonwords. But for recollective judgments, amnesic participants did not produce the crossover interaction for words and nonwords. This striking difference between the performance of memory-intact and amnesic participants demonstrates that recollective judgments and confidence that accompany retrieval are not isomorphic psychological experiences.     

Does Context Discriminate Recollection from Familiarity in Recognition Memory?

Five experiments were conducted to examine subjects' ability to make contextual judgements about recognized items for which they report recollective experience or only familiarity within the context of the experiment. In the first four experiments, subjects were able to make judgements of the spatiotemporal context of items that were accompanied by recollective experience significantly better than for items they merely found familiar. In only one of the four studies did subjects display above-chance performance on spatiotemporal judgements for merely familiar items. A fifth experiment examined the frequency with which subjects report the presence of different kinds of contextual knowledge during a standard recognition experiment. All aspects of contextual knowledge were reported with higher frequencies for recollected items than for items only found familiar, although no single contextual feature was strongly associated with recollective experience. Thus, the five studies together provide converging evidence for the validity of the 'recollect-know' distinction in recognition memory and supplement studies that have already demonstrated that the two kinds of response are dissociable. The implications of these data for group comparisons of memory-impaired patients, and the role of context in recognition memory are discussed.     

The influence of instructions and terminology on the accuracy of remember–know judgments

The remember–know paradigm is one of the most widely used procedures to examine the subjective experience associated with memory retrieval. We examined how the terminology and instructions used to describe the experiences of remembering and knowing affected remember–know judgments. In Experiment 1 we found that using neutral terms, i.e., Type A memory and Type B memory, to describe the experiences of remembering and knowing reduced remember false alarms for younger and older adults as compared to using the terms Remember and Know, thereby increasing overall memory accuracy in the neutral terminology condition. In Experiment 2 we found that using what we call source-specific remember–know instructions, which were intended to constrain remember judgments to recollective experiences arising only from the study context, reduced remember hits and false alarms, and increased know hits and false alarms. Based on these data and other considerations, we conclude that researchers should use neutral terminology and source-specific instructions to collect the most accurate reports of the experiences of remembering and knowing arising from the study context.     

The effect of ageing on the recollection of emotional and neutral pictures

This study investigated age-related differences in recognition memory for emotional and neutral pictures. Younger and older participants were asked to rate pictures according to their emotional valence, arousal, and visual complexity. Two weeks later they had to recognise these pictures and the states of awareness associated with memory were assessed with the "remember/know/guess" paradigm. We found that, although the influence of emotion on recognition accuracy (as assessed by d') was similar in both age groups, the tendency for positive and negative pictures to create a rich recollective experience was weaker in older adults. In addition, "remember" responses were more often based on a recollection of emotional reactions in older than in younger participants. We suggest that the elderly tend to focus on their feelings when confronted with emotional pictures, which could have impaired their memory for the contextual information associated with these stimuli.     

Recollective experience in odor recognition: Influences of adult age and familiarity

We examined recollective experience in odor memory as a function of age, intention to learn, and familiarity. Young and older adults studied a set of familiar and unfamiliar odors with incidental or intentional encoding instructions. At recognition, participants indicated whether their response was based on explicit recollection (remembering), a feeling of familiarity (knowing), or guessing. The results indicated no age-related differences in the distribution of experiential responses for unfamiliar odors. By contrast, for familiar odors the young demonstrated more explicit recollection than the older adults, who produced more know and guess responses. Intention to learn was unrelated to recollective experience. In addition, the observed age differences in remember responses for familiar odors were eliminated when odor naming was statistically controlled. This suggests that age-related deficits in activating specific odor knowledge (i.e., odor names) play an important role for age differences in recollective experience of olfactory information.