Recollection and familiarity in recognition memory: adult age differences and neuropsychological test correlates

Dual process theories account for age-related changes in memory by proposing that old age is associated with deficits in recollection together with invariance in familiarity. The authors evaluated this proposal in recognition by examining recollection and familiarity estimates in young and older adults across 3 process estimation methods: inclusion/exclusion, remember/know, and receiver operating characteristics (ROC). Consistent with a previous literature review (Light, Prull, LaVoie, & Healy, 2000), the authors found age invariance in familiarity when process estimates were derived from the inclusion/exclusion method, but the authors found age differences favoring the young when familiarity estimates were derived from the remember/know and ROC methods. Recollection estimates were lower for older adults in all 3 methods. Recollection and familiarity had variable relationships with frontal- and temporal-lobe measures of neuropsychological functioning in older adults, depending on which method was used to generate process estimates. These data suggest that although recollection deficits appear to be the rule in aging, not all estimates of familiarity show age invariance.     

Recollection can be weak and familiarity can be strong

The remember-know procedure is widely used to investigate recollection and familiarity in recognition memory, but almost all of the results obtained with that procedure can be readily accommodated by a unidimensional model based on signal-detection theory. The unidimensional model holds that remember judgments reflect strong memories (associated with high confidence, high accuracy, and fast reaction times), whereas know judgments reflect weaker memories (associated with lower confidence, lower accuracy, and slower reaction times). Although this is invariably true on average, a new 2-dimensional account (the continuous dual-process model) suggests that remember judgments made with low confidence should be associated with lower old-new accuracy but higher source accuracy than know judgments made with high confidence. We tested this prediction--and found evidence to support it--using a modified remember-know procedure in which participants were first asked to indicate a degree of recollection-based or familiarity-based confidence for each word presented on a recognition test and were then asked to recollect the color (red or blue) and screen location (top or bottom) associated with the word at study. For familiarity-based decisions, old-new accuracy increased with old-new confidence, but source accuracy did not (suggesting that stronger old-new memory was supported by higher degrees of familiarity). For recollection-based decisions, both old-new accuracy and source accuracy increased with old-new confidence (suggesting that stronger old-new memory was supported by higher degrees of recollection). These findings suggest that recollection and familiarity are continuous processes and that participants can indicate which process mainly contributed to their recognition decisions.     

Recollection,not familiarity,decreases in healthy ageing: Converging evidence from four estimation methods

Although it is generally accepted that ageing is associated with recollection impairments, there is considerable disagreement surrounding how healthy ageing influences familiarity-based recognition. One factor that might contribute to the mixed findings regarding age differences in familiarity is the estimation method used to quantify the two mnemonic processes. Here, this issue is examined by having a group of older adults (N = 39) between 40 and 81 years of age complete remember/know (RK), receiver-operating characteristic (ROC) and process dissociation (PD) recognition tests. Estimates of recollection, but not familiarity, showed a significant negative correlation with chronological age. Inconsistent with previous findings, the estimation method did not moderate the relationship between age and estimates of recollection and familiarity. In a final analysis, recollection and familiarity were estimated as latent factors in a confirmatory factor analysis that modelled the covariance between measures of free recall and recognition, and the results converged with the results from the RK, PD and ROC tasks. These results are consistent with the hypothesis that episodic memory declines in older adults are primary driven by recollection deficits, and also suggest that the estimation method plays little to no role in age-related decreases in familiarity.     

Recollection rejection: Gist cuing of verbatim memory

Recollection rejection allows people to avoid accepting related lures presented on recognition tests by recollecting their instantiating study items. Two predictions made by fuzzy trace theoristswere tested. First, recollection rejection should likely occur when verbatim traces are available for retrieval. Second, related lures that closely approximate the gist of their instantiating study items should be more likely to evoke recollection rejection than related lures that do not provide such a match. In support of the first condition, estimates of recollection rejection were lower when participants studied items under divided as opposed to full attention. In support of the second prediction, estimates of recollection rejection were greater when participants were presented with antonyms as related lures, as opposed to rhymes. The present results contribute to the cued recall and recognition literatures by demonstrating that recollection rejection is moderated by similar factors as is cued recall.     

Recollection and familiarity through the looking glass: when old does not mirror new

The authors use the qualitative differences logic to demonstrate that 2 separate memory influences underlie performance in recognition memory tasks, familiarity and recollection. The experiments focus on the mirror effect, the finding that more memorable stimulus classes produce higher hit rates but lower false-alarm rates than less memorable stimulus classes. The authors demonstrate across a number of experiments that manipulations assumed to decrease recollection eliminate or even reverse the hit-rate portion of the mirror effect while leaving the false-alarm portion intact. This occurs whether the critical distinction between conditions is created during the test phase or manipulated during the study phase. Thus, when recollection is present, it dominates familiarity so that the hit-rate portion of the mirror effect primarily reflects recollection; when recollection is largely absent, the opposite pattern associated with the familiarity process emerges.     

The sensorimotor contributions to implicit memory, familiarity, and recollection

The sensorimotor contributions to memory for prior occurrence were investigated. Previous research has shown that both implicit memory and familiarity draw on gains in stimulus-related processing fluency for old, compared with novel, stimuli, but recollection does not. Recently, it has been demonstrated that processing fluency itself resides in stimulus-specific motor simulations or reenactment (e.g., covert pronouncing simulations for words as stimuli). Combining these lines of evidence, it was predicted that stimulus-specific motor interference preventing simulations should impair both implicit memory and familiarity but leave recollection unaffected. This was tested for words as verbal stimuli associated to pronouncing simulations in the oral muscle system (but also for tunes as vocal stimuli and their associated vocal system, Experiment 2). It was found that oral (e.g., chewing gum), compared with manual (kneading a ball), motor interference prevented mere exposure effects (Experiments 1-2), substantially reduced repetition priming in word fragment completion (Experiment 3), reduced the familiarity estimates in a remember-know task (Experiment 5) and in receiver-operating characteristics (Experiment 6), and completely neutralized familiarity measured by self-reports (Experiment 4) and skin conductance responses (Experiment 7), while leaving recollection and free recall unaffected (across Experiments 1-7). This pattern establishes a rare memory dissociation in healthy participants, that is, explicit without implicit memory or recognizing without feeling familiar. Implications for embodied memory and neuropsychology are discussed.     

The perirhinal cortex and long-term familiarity memory

To analyse the functions of the perirhinal cortex, the activity of single neurons in the perirhinal lortex was recorded while macaques performed a delayed matching-to-sample task with up to ohree intervening stimuli. Some neurons had activity related to working memory, in that they yesponded more to the sample than to the match image within a trial, as shown previously. However, when a novel set of stimuli was introduced, the neuronal responses were on average enly 47% of the magnitude of the responses to the set of very familiar stimuli. Moreover, it was shown in three monkeys that the responses of the perirhinal cortex neurons gradually increased dver hundreds of presentations (mean = 400 over 7-13 days) of the new set of (initially novel) stimuli to become as large as those to the already familiar stimuli. Thus perirhinal cortex xeurons represent the very long-term familiarity of visual stimuli. Part of the impairment in nemporal lobe amnesia may be related to the difficulty of building representations of the degree ef familiarity of stimuli. A neural network model of how the perirhinal cortex could implement tong-term familiarity memory is proposed using Hebbian associative learning.     

Memory for details about people: familiarity,relatedness, and gender congruency

This study examines factors that influence memory for details about people. In two experiments, subjects learned fictitious details about familiar (friends, relatives) and/or unfamiliar individuals, and were tested both immediately and after a 1-week delay. To control for a confounding between familiarity and genetic relatedness in Experiment 1, in Experiment 2 specific relationships (identical twin, first cousin, acquaintance) were assigned to unfamiliar individuals. Across experiments, retention was enhanced for familiar compared to unfamiliar individuals, for friends/acquaintances compared to relatives, for more closely than distantly related individuals, and for individuals of the opposite gender as the subject.     

Episodic memory updating: The role of context familiarity

We previously demonstrated that spatial context is a powerful reminder that can trigger memory updating (Hupbach, Hardt, Gomez, & Nadel in Learning & Memory, 15, 574–579 2008). In the present study, we asked whether the familiarity of the spatial context modulates the role of spatial context as a reminder. Since context familiarity can be easily manipulated in children, we chose 5-year-olds as study participants. In two experiments, we demonstrated robust memory-updating effects in children. Spatial context triggered incorporation of new information into old memories only when the context was unfamiliar. In highly familiar spatial environments (children’s homes), spatial context did not initiate memory updating. Other reminders (the experimenter and a reminder question) became highly effective in familiar contexts. These findings shed further light on the specific conditions that trigger memory updating and support the view that the mechanisms underlying it are similar in children and adults.     

The list length effect in recognition memory: an analysis of potential confounds

The list length effect in recognition memory refers to the finding that recognition performance for a short list is superior to that for a long list. The list length effect is consistent with the predictions of item noise models, but context noise models predict no effect. Recently, it has been argued that if potential confounds are controlled, the list length effect is eliminated. We report the results of two experiments in which we looked at the role of attention and the remember–know task in the detection of the list length effect. We conclude that there is no list length effect when potential confounds are controlled and that it is the design used to control for attention that is most vital.     

The perirhinal cortex and long-term familiarity memory.

To analyse the functions of the perirhinal cortex, the activity of single neurons in the perirhinal cortex was recorded while macaques performed a delayed matching-to-sample task with up to three intervening stimuli. Some neurons had activity related to working memory, in that they responded more to the sample than to the match image within a trial, as shown previously. However, when a novel set of stimuli was introduced, the neuronal responses were on average only 47% of the magnitude of the responses to the set of very familiar stimuli. Moreover, it was shown in three monkeys that the responses of the perirhinal cortex neurons gradually increased over hundreds of presentations (mean = 400 over 7-13 days) of the new set of (initially novel) stimuli to become as large as those to the already familiar stimuli. Thus perirhinal cortex neurons represent the very long-term familiarity of visual stimuli. Part of the impairment in temporal lobe amnesia may be related to the difficulty of building representations of the degree of familiarity of stimuli. A neural network model of how the perirhinal cortex could implement long-term familiarity memory is proposed using Hebbian associative learning.     

The ability of familiarity, disruption, and the relative strength of nonenvironmental context cues to explain unreliable environmental-context-dependent memory effects in free recall

The ability of environmental-context (EC) familiarity, movement disruption, and the relative strength of memory cues to explain unreliable EC-dependent free-recall memory effects was examined in two experiments. Experiment 1 replicated Smith's (1979, Experiment 1) results confirming that familiarity and disruption cannot account for free-recall EC-reinstatement effects. In Experiment 2, a level of processing manipulation varied stimulus item memory cue strengths, and memory was again assessed by free recall. Contrary to Murnane and Phelps's (1995) and Dougal and Rotello's (1999) recognition findings, an EC-reinstatement effect was observed with low, but not high, levels of processing. However, comparisons across the two experiments revealed inconsistencies with the relative cue strength hypothesis. Consequently, a variant of the relative cue strength hypothesis that highlights the role of retrieval processes was proposed to explain the interaction between the levels of processing and the EC-reinstatement effect.     

Acoustic confusion of digits in memory and recognition

It has been shown that, contrary to current opinion, digits do not confuse arbitrarily and that similar patterns of confusion are observed in memory and auditory recognition tasks. Two alternative measures of stimulus similarity are compared.     

Recognition memory strength is predicted by pupillary responses at encoding while fixation patterns distinguish recollection from familiarity

Thirty-five healthy participants incidentally encoded a set of man-made and natural object pictures, while their pupil response and eye movements were recorded. At retrieval, studied and new stimuli were rated as novel, familiar (strong, moderate, or weak), or recollected. We found that both pupil response and fixation patterns at encoding predict later recognition memory strength. The extent of pupillary response accompanying incidental encoding was found to be predictive of subsequent memory. In addition, the number of fixations was also predictive of later recognition memory strength, suggesting that the accumulation of greater visual detail, even for single objects, is critical for the creation of a strong memory. Moreover, fixation patterns at encoding distinguished between recollection and familiarity at retrieval, with more dispersed fixations predicting familiarity and more clustered fixations predicting recollection. These data reveal close links between the autonomic control of pupil responses and eye movement patterns on the one hand and memory encoding on the other. Moreover, the data illustrate quantitative as well as qualitative differences in the incidental visual processing of stimuli, which are differentially predictive of the strength and the kind of memory experienced at recognition.     

Recognition memory strength is predicted by pupillary responses at encoding while fixation patterns distinguish recollection from familiarity

Thirty-five healthy participants incidentally encoded a set of man-made and natural object pictures, while their pupil response and eye movements were recorded. At retrieval, studied and new stimuli were rated as novel, familiar (strong, moderate, or weak), or recollected. We found that both pupil response and fixation patterns at encoding predict later recognition memory strength. The extent of pupillary response accompanying incidental encoding was found to be predictive of subsequent memory. In addition, the number of fixations was also predictive of later recognition memory strength, suggesting that the accumulation of greater visual detail, even for single objects, is critical for the creation of a strong memory. Moreover, fixation patterns at encoding distinguished between recollection and familiarity at retrieval, with more dispersed fixations predicting familiarity and more clustered fixations predicting recollection. These data reveal close links between the autonomic control of pupil responses and eye movement patterns on the one hand and memory encoding on the other. Moreover, the data illustrate quantitative as well as qualitative differences in the incidental visual processing of stimuli, which are differentially predictive of the strength and the kind of memory experienced at recognition.     

Exhaustive memory-scanning and familiarity discrimination: Separate mechanisms in recognition memory tasks

Experiment I was a yes-no recognition task with lists of one, two or four items to remember. Each item in the experiment appeared in only one list, and each list was presented only once. One group of subjects performed the task with complex pictures. Their results were incompatible with the hypothesis of exhaustive memory scanning, since the function relating “yes” response latency to list length was not parallel to but steeper than the function for “no” responses. Another group performed the task with words. Their results were consistent with exhaustive memory-scanning. Experiment II was a similar task in which the familiarity was varied of the test items to which the subjects had to respond “no”. That variation affected response latency with pictures but not with words. From these results and from a consideration of relevant neurological data, the hypothesis is advanced that familiarity discrimination and exhaustive memory-scanning are separate mechanisms.     

一体化促进联结记忆的作用机制：熟悉性和回想加工

当两个或两个以上项目进行一体化编码时, 熟悉性也能够支持联结再认, 这一观点已经得到大量研究证据的支持。然而, 关于一体化如何影响联结再认和构成联结的单个项目再认仍存在分歧。通过回顾现有研究发现：(1)一体化一致性是调节一体化与联结再认关系的重要因素; (2)认知资源有限和新/旧词语义相关性是影响一体化对项目再认作用的重要因素; (3)一体化的发生机制存在“项目假说”、“图式假说”以及“精细加工假说”三种可能的理论解释。未来研究不仅需要控制一体化一致性, 还可以比较不同一体化方式的作用大小以及探索一体化效应的毕生发展规律。     

Context effects in recognition memory: the role of familiarity and recollection

A variant of the process dissociation procedure was coupled with a manipulation of response signal lag to assess whether manipulations of context affect one or both of the familiarity and search processes described by the dual process model of recognition. Participants studied a list of word pairs (context+target) followed by a recognition test with target words presented in the same or different context, and in the same or different form as study (singular/plural). Participants were asked to recognize any target word regardless of changes to form (inclusion), or to only recognise words that were presented in the same form (exclusion). The standard context reinstatement effect was evident even at the short response lags. Analyses of the estimates of the contributions of familiarity and search processes suggest that the context effect demonstrated here can be attributed in part to the influence of familiarity on recognition, whereas the effect on recollection was less clear.     

Differential effects of list strength on recollection and familiarity

Numerous studies have found a null list strength effect (LSE) for recognition sensitivity: Strengthening memory traces associated with some studied items does not impair recognition of nonstrengthened studied items. In Experiment 1, the author found a LSE using receiver operating characteristic-based measures of recognition sensitivity. To account for the discrepancy between this and prior research, the author (a) argues that a LSE occurs for recollection but not for discrimination based on familiarity, and (b) presents self-report data consistent with this hypothesis. Experiment 2 tested the dual-process hypothesis more directly, using switched-plurality (SP) lures to isolate the contribution of recollection. There was a significant LSE for comparisons involving SP lures; the LSE for discrimination of studied items and nominally unrelated lures (which can be supported by familiarity) was not significant.