Familiarity-based Recognition Memory Research Articles

Soliciting judgments of learning reactively facilitates both recollection- and familiarity-based recognition memory

Soliciting judgments of learning reactively facilitates both recollection- and familiarity-based recognition memory

Object memory is multisensory: Task-irrelevant sounds improve recollection

Hearing a task-irrelevant sound during object encoding can improve visual recognition memory when the sound is object-congruent (e.g., a dog and a bark). However, previous studies have only used binary old/new memory tests, which do not distinguish between recognition based on the recollection of details about the studied event or stimulus familiarity. In the present research, we hypothesized that hearing a task-irrelevant but semantically congruent natural sound at encoding would facilitate the formation of richer memory representations, resulting in increased recollection of details of the encoded event. Experiment 1 replicates previous studies showing that participants were more confident about their memory for items that were initially encoded with a congruent sound compared to an incongruent sound. Experiment 2 suggests that congruent object-sound pairings specifically facilitate recollection and not familiarity-based recognition memory, and Experiment 3 demonstrates that this effect was coupled with more accurate memory for audiovisual congruency of the item and sound from encoding rather than another aspect of the episode. These results suggest that even when congruent sounds are task-irrelevant, they promote formation of multisensory memories and subsequent recollection-based retention. Given the ubiquity of encounters with multisensory objects in our everyday lives, considering their impact on episodic memory is integral to building models of memory that apply to naturalistic settings.

Impaired recollection and initially preserved familiarity in a patient with bilateral fornix transection following third ventricle colloid cyst removal: A two-year follow-up study

Objective Recognition memory is widely accepted as a dual process-based model, namely familiarity and recollection. However, the location of their specific neurobiological substrates remains unclear. Similar to hippocampal damage, fornix damage has been associated with recollection memory but not familiarity memory deficits. To understand the neural basis of recognition memory, determining the importance of the fornix and its hippocampal connections is essential. Methods Recognition memory was examined in a 45-year-old male who underwent a complete bilateral fornix section following the removal of a third ventricle colloid cyst. The application of familiarity and recollection for recognition memory decisions was investigated via an immediate and delayed associative recognition test and an immediate and delayed forced-choice task in the patient and a control group (N = 15) over a two-year follow-up period. Complete demographic, neuropsychological, neuropsychiatric, and neuroradiological characterizations of this patient were performed. Results Persistent immediate and delayed verbal recollection memory deficits were observed in the patient. Moreover, delayed familiarity-based recognition memory declined gradually over the follow-up period, immediate familiarity-based recognition memory was unaffected, and reduced non-verbal memory improved. Conclusion The present findings support models that the extended hippocampal system, including the fornices, does not appear to play a role in familiarity memory but is particularly important for recollection memory. Moreover, our study suggests that bilateral fornix transection may be associated with relatively functional recovery of non-verbal memory.

Novelty processing associated with neural beta oscillations improves recognition memory in young and older adults.

Novelty anticipation activates the mesolimbic system and promotes subsequent long-term memory in younger adults. Importantly, mesolimbic structures typically degenerate with age, which might reduce positive effects of novelty anticipation. Here, we used electroencephalography in combination with an established paradigm in healthy young (19-33 years old, n=28) and older (53-84, n=27) humans. Colored cues predicted the subsequent presentation of either a novel or previously familiarized image (75% cue validity). On the subsequent day, recognition memory for the novel images was tested. Behaviorally, novelty anticipation improved recollection-based but not familiarity-based recognition memory in both groups, and this effect was more pronounced in older subjects. Furthermore, novelty and familiarity cues increased theta (4-8 Hz) and decreased alpha/beta power (9-20 Hz); at outcome, expected novel and familiar images both increased beta power (13-25 Hz). Finally, a subsequent memory effect for expected novel images was associated with increases in beta power independent of age. Together, novelty anticipation drives hippocampus-dependent long-term recognition memory across the life span, and this effect appears to be related to neural beta oscillations.

Bridging novelty and familiarity-based recognition memory: A matter of timing

ABSTRACTNovelty detection is essential to adapt to changes. However, the relationship between novelty detection and visual recognition memory remains unclear. To characterize the temporal dynamics of novelty and its connection to familiarity, we probed early behavioural performance of novelty and familiarity in 31 participants using a speeded go/no-go recognition task with a 600-ms response deadline. Responses to familiarity and novelty produced symmetrical biases and correlated accuracies and biases, but novelty decisions were less accurate and had slower minimal reaction times (410 ms). These processes thus appear to be independent, as suggested by a more efficient system in the case of familiarity, but with common factors bringing overlapping contributions to both processes. This may possibly be explained by the more fluent processing of repeated stimuli, but with familiarity and novelty potentially relying on one decision criterion, as suggested by the correlated and remarkably symmetrical biases. This study supports models that conceptualize novelty and familiarity decisions as two partly overlapping processes.

The impact of aging on associative memory for preexisting unitized associations

ABSTRACTAging is accompanied by a decline in associative memory that can, however, be attenuated when associations are unitized at encoding, that is, when they form an integrated entity. Unitization is thought to promote familiarity-based recognition memory, which is preserved in aging. We examined whether preexperimentally unitized associations (compound words (CWs)) do indeed reduce age differences in memory, and whether preexperimental unitization promotes familiarity. In Experiment 1, we assessed the memory of 20 young and 20 older participants for compound versus unrelated word pairs using a yes/no recognition test with Remember/Know/Guess judgments. In Experiment 2, we tested 20 young and 20 older participants using the same procedure, except for the use of a two-alternative forced-choice recognition paradigm, which is thought to enhance the contribution of familiarity. The results of both experiments corroborated the greater contribution of familiarity to recognition of unitized associations. In Experiment 1, however, the use of CWs did not attenuate the age-related associative decline. We suggest that preexisting knowledge associated with recombined compounds induced high absolute familiarity and illusory recollection, leading to high false-recognition rates for the older adults. By contrast, the two groups performed similarly across both conditions in Experiment 2. Thus, the forced-choice procedure facilitates the use of familiarity in such a way that it improves older adults’ associative memory to the level of young participants. These results suggest that the modulation of associative memory in aging by preexisting unitization varies according to methodological parameters, such as the nature of the lures and the test format.

Selective lesion to the entorhinal cortex leads to an impairment in familiarity but not recollection

The present research explored the effects of selective impairment to the entorhinal cortex on the processes of familiarity and recollection. To achieve this objective, the performance of patient MR, who has a selective impairment of the left entorhinal cortex, was compared to that of age and IQ-matched controls. Four experiments tested participants’ recognition memory for familiar and unfamiliar faces and words. In all experiments, participants studied lists of items and then completed an old/new recognition test in which they also made remember/know/guess judgements. A fifth experiment tested participants’ priming associated with the familiarity process. MR had intact performance in both face recognition experiments as well as having intact performance in pseudoword recognition. Crucially, however, in the familiar word experiment, whilst MR performed similarly to control participants in terms of recollection, she showed a marked impairment in familiarity. Furthermore, she also demonstrated a reversed conceptual priming effect. MR’s impairment is both material-specific and selective for previously encountered but not new verbal items (pseudowords). These findings provide the first clear evidence that selective impairment of the entorhinal cortex impairs the familiarity process for familiar verbal material whilst leaving recollection intact. These results suggest the entorhinal cortex does not have attributes reflective of both recollection and familiarity as previously assumed, but rather supports context-free long-term familiarity-based recognition memory.

Differential effects of stress-induced cortisol responses on recollection and familiarity-based recognition memory

Stress-induced changes in cortisol can impact memory in various ways. However, the precise relationship between cortisol and recognition memory is still poorly understood. For instance, there is reason to believe that stress could differentially affect recollection-based memory, which depends on the hippocampus, and familiarity-based recognition, which can be supported by neocortical areas alone. Accordingly, in the current study we examined the effects of stress-related changes in cortisol on the processes underlying recognition memory. Stress was induced with a cold-pressor test after incidental encoding of emotional and neutral pictures, and recollection and familiarity-based recognition memory were measured one day later. The relationship between stress-induced cortisol responses and recollection was non-monotonic, such that subjects with moderate stress-related increases in cortisol had the highest levels of recollection. In contrast, stress-related cortisol responses were linearly related to increases in familiarity. In addition, measures of cortisol taken at the onset of the experiment showed that individuals with higher levels of pre-learning cortisol had lower levels of both recollection and familiarity. The results are consistent with the proposition that hippocampal-dependent memory processes such as recollection function optimally under moderate levels of stress, whereas more cortically-based processes such as familiarity are enhanced even with higher levels of stress. These results indicate that whether post-encoding stress improves or disrupts recognition memory depends on the specific memory process examined as well as the magnitude of the stress-induced cortisol response.

Recognition Memory: An Old Idea Given New Life

A new study combining behavioral and physiological approaches has given new life to the old idea that the hippocampus is critically involved in familiarity-based recognition memory.

Cold-pressor stress after learning enhances familiarity-based recognition memory in men

Stress that is experienced after items have been encoded into memory can protect memories from the effects of forgetting. However, very little is known about how stress impacts recognition memory. The current study investigated how an aversive laboratory stressor (i.e., the cold-pressor test) that occurs after information has been encoded into memory affects subsequent recognition memory in an immediate and a delayed test (i.e., 2-h and 3-month retention interval). Recognition was assessed for negative and neutral photographs using a hybrid remember/know confidence procedure in order to characterize overall performance and to separate recollection- and familiarity-based responses. The results indicated that relative to a non-stress control condition, post-encoding stress significantly improved familiarity but not recollection-based recognition memory or free recall. The beneficial effects of stress were observed in males for negative and neutral materials at both immediate and long-term delays, but were not significant in females. The results indicate that aversive stress can have long-lasting beneficial effects on the memory strength of information encountered prior to the stressful event.

Recollection, familiarity, and content-sensitivity in lateral parietal cortex: a high-resolution fMRI study.

Numerous studies have identified brain regions where activity is consistently correlated with the retrieval (recollection) of qualitative episodic information. This ‘core recollection network’ can be contrasted with regions where activity differs according to the contents of retrieval. The present study used high-resolution fMRI to investigate whether these putatively-distinct retrieval processes engage common versus dissociable regions. Subjects studied words with two encoding tasks and then performed a memory test in which they distinguished between recollection and different levels of recognition confidence. The fMRI data from study and test revealed several overlapping regions where activity differed according to encoding task, suggesting that content was selectively reinstated during retrieval. The majority of recollection-related regions, though, did not exhibit reinstatement effects, providing support for a core recollection network. Importantly, lateral parietal cortex demonstrated a clear dissociation, whereby recollection effects were localized to angular gyrus and confidence effects were restricted to intraparietal sulcus. Moreover, the latter region exhibited a non-monotonic pattern, consistent with a neural signal reflecting item familiarity rather than a generic form of memory strength. Together, the findings show that episodic retrieval relies on both content-sensitive and core recollective processes, and these can be differentiated from familiarity-based recognition memory.

Familiarity is related to conceptual implicit memory: an examination of individual differences.

Explicit memory is thought to be distinct from implicit memory. However, growing evidence has indicated that explicit familiarity-based recognition memory judgments rely on the same process that supports conceptual implicit memory. We tested this hypothesis by examining individual differences using a paradigm wherein we measured both familiarity and conceptual implicit memory within the same participants. In Experiments 1a and 1b, we examined recognition memory confidence ROCs and remember/know responses, respectively, to estimate recollection and familiarity, and used a free association task to measure conceptual implicit memory. The results demonstrated that, across participants, familiarity, but not recollection, was significantly correlated with conceptual priming. In contrast, in Experiment 2, utilizing a similar paradigm, a comparison of recognition memory ROCs and explicit associative cued-recall performance indicated that cued recall was related to both recollection and familiarity. These results are consistent with models assuming that familiarity-based recognition and conceptual implicit memory rely on similar underlying processes.

Effects of Age on the Neural Correlates of Familiarity as Indexed by ERPs

ERPs were recorded from samples of young (18-29 years) and older (63-77 years) participants while they performed a modified "remember-know" recognition memory test. ERP correlates of familiarity-driven recognition were obtained by contrasting the waveforms elicited by unrecollected test items accorded "confident old" and "confident new" judgments. Correlates of recollection were identified by contrasting the ERPs elicited by items accorded "remember" and confident old judgments. Behavioral analyses revealed lower estimates of both recollection and familiarity in older participants than in young participants. The putative ERP correlate of recollection-the "left parietal old-new effect"-was evident in both age groups, although it was slightly but significantly smaller in the older sample. By contrast, the putative ERP correlate of familiarity-the "midfrontal old-new effect"-could be identified in young participants only. This age-related difference in the sensitivity of ERPs to familiarity was also evident in subgroups of young and older participants, in whom familiarity-based recognition performance was equivalent. Thus, the inability to detect a reliable midfrontal old-new effect in older participants was not a consequence of an age-related decline in the strength of familiarity. These findings raise the possibility that familiarity-based recognition memory depends upon qualitatively different memory signals in older and young adults.

Right Frontal Lobe Mediation of Recollection- and Familiarity-based Verbal Recognition Memory: Evidence from Patients with Tumor Resections

Medial-temporal, parietal, and pFC regions have been implicated in recollection and familiarity, but existing evidence from neuroimaging and patient studies is limited and conflicting regarding the role of specific regions within pFC in these memory processes. We report a study of 20 patients who had undergone resection of right frontal lobe tumors and 20 matched healthy control participants. The location and extent of lesions were traced on the patients' scans. A process dissociation procedure was employed to yield estimates of the contributions of recollection and familiarity in verbal recognition performance. Group comparisons revealed deficits in recollection but not familiarity in the patient group relative to their healthy counterparts. We found a positive relationship between estimates of familiarity and lesion sizes in the right inferior pFC (BA 11, 47) which was significant upon bootstrap resampling. These results are discussed in terms of prior work linking this area to an overextended sense of familiarity.

The Medial Temporal Lobe Supports Conceptual Implicit Memory

The medial temporal lobe (MTL) is generally thought to be critical for explicit, but not implicit, memory. Here, we demonstrate that the perirhinal cortex (PRc), within the MTL, plays a role in conceptually-driven implicit memory. Amnesic patients with MTL lesions that converged on the left PRc exhibited deficits on two conceptual implicit tasks (i.e., exemplar generation and semantic decision). A separate functional magnetic resonance imaging (fMRI) study in healthy subjects indicated that PRc activation during encoding of words was predictive of subsequent exemplar generation. Moreover, across subjects, the magnitude of the fMRI and behavioral conceptual priming effects were directly related. Additionally, the PRc region implicated in the fMRI study was the same region of maximal lesion overlap in the patients with impaired conceptual priming. These patient and imaging results converge to suggest that the PRc plays a critical role in conceptual implicit memory, and possibly conceptual processing in general.

Effect of intranasally administered cholecystokinin on encoding of controlled and automatic memory processes

The neuropeptide cholecystokinin (CCK) is present in abundance in the central nervous system, where it is involved in the regulation of a wide range of functions. It also takes part in the modulation of memory processes, but its effect on human memory systems and processes is not yet well understood. The present experiment was conducted to examine the influence of CCK when present during encoding on later controlled and automatic recognition memory processes in humans. A version of the process dissociation procedure was used to separate the contributions of controlled and automatic memory processes to participants' recognition memory performance. Data were analyzed within a multinomial modeling framework. Participants (N = 64) received either 40 microg CCK-8S or placebo intranasally. The learning and test phases began 30 min after substance application. Behavioral, physiological, and self-report control variables were measured at three points of time during the experiment. Compared to placebo, CCK increased the automatic, familiarity-based recognition memory component, while the parameter representing controlled, retrieval-based processes did not differ between groups. Also, in the exclusion condition of the test phase, the guessing parameter was reduced by CCK. None of the control variables were affected by the peptide. This result-the enhancement of the automatic recognition memory component when CCK is applied before encoding (and thus present during encoding and retrieval)-complements earlier results indicating that CCK decreases controlled, recollection-based recognition memory when applied during consolidation. The possible neuronal systems and processes mediating these effects are discussed.

Selective disruption of hippocampus-mediated recognition memory processes after episodes of transient global amnesia

Transient global amnesia (TGA) is characterized by the abrupt onset of severe amnesia without concomitant focal neurological symptoms. Recent studies revealed that small and punctate MR-signal diffusion-weighted imaging (DWI) lesions can be found within the hippocampus of TGA patients during the post-acute phase. On the basis of dual-process models of recognition memory, the present study examined the hypothesis that hippocampal dysfunction as suggested by these DWI lesions disrupts hippocampus-mediated recollection in patients with TGA, whereas familiarity-based recognition memory that is assumed to be supported by extra-hippocampal brain regions should be unaffected. We administered a recognition memory task for faces and words to eleven TGA patients during the post-acute phase and to eleven matched controls. Receiver operating characteristics (ROCs) were obtained in order to derive estimates of familiarity and recollection by applying a formal dual-process model of recognition memory. Analyses of ROC curves revealed a disruption of recollection in TGA patients’ memory for words [ t(20) = 2.70, p < .05], but no difference in familiarity-based recognition memory between patients and controls [ t(20) = −1.10, p = .284]. Post hoc analyses indicated that the deficit in recollection is more pronounced in TGA patients who show visible hippocampal lesions on diffusion-weighted MR imaging compared to those without detectable hippocampal lesions. In conclusion, consistent with recent neuroanatomical dual-process models of recognition memory, hippocampal dysfunction in patients with TGA is associated with a selective effect on specific recognition memory subprocesses.

Bridging the gap between the semantic N400 and the early old/new memory effect

We set out to investigate the extent to which semantic integration processes during language comprehension indexed by the N400 component affect subsequent declarative memory processes as revealed by the putative event-related potential correlates of familiarity and recollection. To this end we designed an incidental recognition memory test whose study material was composed of sentences that were either correct or contained a semantic or syntactic violation. By this means it was possible to examine the mnemonic consequences of the N400 amplitude at study. We found a significant correlation between the amplitude of the N400 at encoding and the magnitude of the familiarity-related early old/new effect at test. It is argued that the processes that contributed to N400 generation increase the likelihood of familiarity-based recognition memory.

Remember–Know judgments and retrieval of contextual details

The Remember–Know (R–K) task is commonly used to differentiate between recollection and familiarity-based recognition memory. To further validate this test, we assessed the number of contextual details available to participants after giving R or K responses. We also examined the effect of retention interval on the episodic character of memories by administering the R–K task after both 10-minute and 1-week retention intervals. At 1 week, items receiving R responses were accompanied by a significant number of episodic details, while K responses were not. A large number of items that received R responses at the 10-minute delay received K responses at 1 week, and these items were not accompanied by episodic detail during the later test. Items that were judged familiar at 10-minutes but were labeled as recollected at 1 week were also not accompanied by significant memory of the study episode, suggesting that these items were recollected from the first test session. Overall, the data are consistent with the idea that R responses, unlike K responses, are accompanied by memory for episodic detail, and that the loss of memory for episodic detail over time parallels the conversion of R responses to K responses.

The Role of the Human Medial Temporal Lobe in Object Recognition and Object Discrimination

This paper reviews evidence from neuropsychological patient studies relevant to two questions concerning the functions of the medial temporal lobe in humans. The first is whether the hippocampus and the adjacent perirhinal cortex make different contributions to memory. Data are discussed from two patients with adult-onset bilateral hippocampal damage who show a sparing of item recognition relative to recall and certain types of associative recognition. It is argued that these data are consistent with Aggleton and Brown's (1999) proposal that familiarity-based recognition memory is not dependent on the hippocampus but is mediated by the perirhinal cortex and dorso-medial thalamic nucleus. The second question is whether the recognition memory deficit observed in medial temporal lobe amnesia can be explained by a deficit in perceptual processing and representation of objects rather than a deficit in memory per se. The finding that amnesics were impaired at recognizing, after short delays, patterns that they could successfully discriminate suggests that their memory impairment did not result from an object-processing deficit. The possibility remains, however, that the human perirhinal cortex plays a role in object processing, as well as in recognition memory, and data are presented that support this possibility.