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.     

Reinstating effortful encoding operations at test enhances episodic remembering

Two experiments investigated the effects of reinstating encoding operations on remember and know responses in recognition memory. Experiment 1 showed that reinstating an effortful encoding task (generating words from fragments) increased remember responses at test but reinstating an automatic encoding task (reading intact words) did not. This pattern was confirmed in Experiment 2 in which words were either read intact or generated from anagrams. These findings show that repeating effortful (but not automatic) encoding operations at test cues not only the recognition of the information that was acquired via those operations but also the conscious recollection of the encoding episode.     

Reinstating effortful encoding operations at test enhances episodic remembering

Two experiments investigated the effects of reinstating encoding operations on remember and know responses in recognition memory. Experiment 1 showed that reinstating an effortful encoding task (generating words from fragments) increased remember responses at test but reinstating an automatic encoding task (reading intact words) did not. This pattern was confirmed in Experiment 2 in which words were either read intact or generated from anagrams. These findings show that repeating effortful (but not automatic) encoding operations at test cues not only the recognition of the information that was acquired via those operations but also the conscious recollection of the encoding episode.     

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.     

On the origin of functional differences in recollective experience

Abstract

Subjects studied target words that were repeated either immediately (lag0) or after six intervening items (lag6). At retention testing, subjects were required to discriminate targets from distractors and, contingent on a ‘yes' response, to classify each identified item as one that evoked either a ‘remember’ (R) response or a ‘know’ (K) response. An R response indicated recognition based on conscious recollection, and K, recognition without conscious recollection. R responses were significantly greater in lag6 than lag0 whereas the reverse was found for K responses. The data are interpreted as showing that R responses depend on the probability of a target stimulus engaging conscious effortful processing, whereas K responses are increased in the absence of conscious involvement at learning.     

Memory awareness following speeded compared with unspeeded picture recognition

A remember-know paradigm was used to assess memory awareness following speeded and unspeeded yes/no picture recognition. The beneficial effects of picture size congruency at study and test occurred with speeded as well as with unspeeded recognition. In each case, they were associated with remembering, not with knowing, which remained invariant. Thus, size congruency effects were associated with remembering even when recognition occurred more automatically and hence may be more dependent on a relatively fast familiarity process. In a second experiment, speeded remember responses were compared with remember responses that followed speeded yes/no recognition. There was more remembering when it was the remember responses that were speeded, contrary to what might be expected if remembering reflects a relatively slow recollection process. These results have implications for the ability of dual-process models of recognition memory to account for memory awareness.     

Slow wave sleep and recollection in recognition memory

Recognition memory performance reflects two distinct memory processes: a conscious process of recollection, which allows remembering specific details of a previous event, and familiarity, which emerges in the absence of any conscious information about the context in which the event occurred. Slow wave sleep (SWS) and rapid eye movement (REM) sleep are differentially involved in the consolidation of different types of memory. The study assessed the effects of SWS and REM sleep on recollection, by means of the "remember"/"know" paradigm. Subjects studied three blocks of 12 words before a 3-h retention interval filled with SWS, REM sleep or wakefulness, placed between 3 a.m. and 6 a.m. Afterwards, recognition and recollection were tested. Recollection was higher after a retention interval rich in SWS than after a retention interval rich in REM sleep or filled with wakefulness. The results suggest that SWS facilitates the process of recollection in recognition memory.     

Processing fluency affects subjective claims of recollection

Previous studies that have used the remember-know paradigm to investigate subjective awareness in memory have shown that fluency manipulations have an impact on "know" responses but not on "remember" responses (e.g., Rajaram, 1993), a finding typically accounted for by invoking inferential processing in judgments of familiarity but not of recollection. However, in light of several researchers' criticisms of this procedure, as well as findings documenting the influence of processing fluency on various subjective judgments, the present study was conducted in order to investigate whether judgments of recollection might also be subject to inferential processes and not solely the product of conscious retrieval. When the standard remember-know procedure was used (Experiment 1), manipulations of perceptual fluency increased "know" responses but had no effect on "remember" responses, replicating previous findings. However, when an independent ratings method was employed (Higham & Vokey, 2004), manipulations of perceptual fluency (Experiment 2) and conceptual fluency (Experiment 3) reliably increased claims of both familiarity and recollection, suggesting that the conclusion that fluency affects only "know" responses may be an artifact of the standard remember-know procedure.     

Subjective qualities of memories associated with the picture superiority effect in schizophrenia

Patients with schizophrenia (n = 24) matched with 24 normal subjects were presented with both words and pictures. On a recognition memory task, they were asked to give remember, know, or guess responses to items that were recognized on the basis of conscious recollection, familiarity, or guessing, respectively. Compared with normal subjects, patients exhibited a lower picture superiority effect selectively related to remember responses. Unlike normal subjects, they did not exhibit any word superiority effect in relation to guess responses; this explains why the overall picture superiority effect appeared to be intact. These results emphasize the need to take into account the subjective states of awareness when analyzing memory impairments in schizophrenia.     

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.     

The Role of Decision Processes in Conscious Recollection

Dual-process models of recognition memory posit a rapid retrieval process that produces a general sense of familiarity and a slower retrieval process that produces conscious recollections of prior experience. The remember / know paradigm has been used to study the subjective correlates of these two processes, with remember judgments assumed to index conscious recollection and know judgments assumed to index familiarity. Recently, a two-criterion signal detection model has been proposed as an alternative account of this paradigm. This model assumes only a single memory process with a criterion remember from know responses. This report presents an empirical test of the model's critical prediction that manipulations that influence criterion placement should influence both remember and know judgments. An experiment confirmed this prediction, demonstrating that subjects who were told that 70% of the test items were study items produced more remember and know responses than subjects who were told that 30% of the test items were study items.     

Signal-Detection, Threshold, and Dual-Process Models of Recognition Memory: ROCs and Conscious Recollection

Threshold- and signal-detection-based models have dominated theorizing about recognition memory. Building upon these theoretical frameworks, we have argued for a dual-process model in which conscious recollection (a threshold process) and familiarity (a signal-detection process) contribute to memory performance. In the current paper we assessed several memory models by examining the effects of levels of processing and the number of presentations on recognition memory receiver operating characteristics (ROCs). In general, when the ROCs were plotted in probability space they exhibited an inverted U shape; however, when they were plotted inzspace they exhibited a U shape. An examination of the ROCs showed that the dual-process model could account for the observed ROCs, but that models based solely on either threshold or signal-detection processes failed to provide a sufficient account of the data. Furthermore, an examination of subjects' introspective reports using the remember/know procedure showed that subjects were aware of recollection and familiarity and were able to consistently report on their occurrence. The remember/know data were used to accurately predict the shapes of the ROCs, and estimates of recollection and familiarity derived from the ROC data mirrored the subjective reports of these processes.     

负性情绪强度对双加工再认提取的影响

双加工理论认为再认提取存在回想和熟悉性两种认知加工过程。本研究采用修正的“记得/知道”范式,考察不同强度的负性情绪对这两种再认提取过程的影响。结果发现：（1）在记得反应上不同负性情绪强度的材料呈现出以下模式：高度负性 > 中度负性 > 轻度负性 > 中性;（2）在知道反应上,不同负性情绪强度的材料呈现出以下模式：中性 > 轻度负性 > 中度负性 > 高度负性。这些结果表明,不同强度的负性材料对情绪记忆的影响表现为两条途径：依赖于回想的再认随着负性情绪强度的增加而逐步提高,另外一个依赖于熟悉性的再认随着负性情绪强度的增加而逐步降低。     

Verbal predicates foster conscious recollection but not familiarity of a task-irrelevant perceptual feature – An ERP study

Research on the effects of perceptual manipulations on recognition memory has suggested that (a) recollection is selectively influenced by task-relevant information and (b) familiarity can be considered perceptually specific. The present experiment tested divergent assumptions that (a) perceptual features can influence conscious object recollection via verbal code despite being task-irrelevant and that (b) perceptual features do not influence object familiarity if study is verbal-conceptual. At study, subjects named objects and their presentation colour; this was followed by an old/new object recognition test. Event-related potentials (ERP) showed that a study-test manipulation of colour impacted selectively on the ERP effect associated with recollection, while a size manipulation showed no effect. It is concluded that (a) verbal predicates generated at study are potent episodic memory agents that modulate recollection even if the recovered feature information is task-irrelevant and (b) commonly found perceptual match effects on familiarity critically depend on perceptual processing at study.     

Recognition memory for pictorial material in subclinical depression

Depression has been associated with impaired recollection of episodic details in tests of recognition memory that use verbal material. In two experiments, the remember/know procedure was employed to investigate the effects of dysphoric mood on recognition memory for pictorial materials that may not be subject to the same processing limitations found for verbal materials in depression. In Experiment 1, where the recognition test took place two weeks after encoding, subclinically depressed participants reported fewer know judgements which were likely to be at least partly due to a remember-to-know shift. Although pictures were accompanied by negative or neutral captions at encoding, no effect of captions on recognition memory was observed. In Experiment 2, where the recognition test occurred soon after viewing the pictures, subclinically depressed participants reported fewer remember judgements. All participants reported more remember judgements for pictures of emotionally negative content than pictures of neutral content. Together, these findings demonstrate that recognition memory for pictorial stimuli is compromised in dysphoric individuals in a way that is consistent with a recollection deficit for episodic detail and also reminiscent of that previously reported for verbal materials. These findings contribute to our developing understanding of how mood and memory interact.     

Recollective experience in the revelation effect: Separating the contributions of recollection and familiarity

The revelation effect is a phenomenon of recognition memory in which words presented for a recognition decision are more likely to be identified as previously studied if they are initially disguised and are then somehow revealed to the subject. The goal of the present experiments was to determine whether the revelation effect has similar or different influences on the conscious recollection of a previous encounter with a test item and on the feeling of familiarity evoked by a test item. The process-dissociation procedure (Experiment 1) and the remember/know procedure (Experiment 2) were used to achieve this goal. The main findings of these experiments were that revealing an item at test (1) increased the feeling of familiarity associated with that item, especially if it was not previously studied, and (2) decreased conscious recollection of previously studied items. These data narrow the range of potential explanations of the revelation effect.     

Are nonconscious processes sufficient to produce false memories?

Seamon, Luo, and Gallo (1998) reported evidence that nonconscious processes could produce false recognition in a converging-associates task, whereby subjects falsely remember a nonstudied lure (e.g., sleep) after studying a list of related words (bed, rest, awake...). Zeelenberg, Plomp, and Raaijmakers (2003) failed to observe this false recognition effect when list word recognition was at chance. We critically evaluate the evidence for nonsconscious processing and report the results of a new experiment designed to overcome previous methodological limitations. Consistent with Seamon et al., we found that conscious activation of a related lure during study was not necessary for its subsequent recognition; consistent with Zeelenberg et al., we found no evidence for recognition of related lures under conditions where there was no memory for studied words. It is currently unknown whether conscious recollection of the studied items is necessary for false recognition or if nonconscious activation of the lure is sufficient.     

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.     

The role of extralist associations in false

The finding that new items are judged as remembered in the remember-know paradigm presents a challenge to traditional process and systems accounts of memory. In three experiments, we demonstrated that false remember responses can be caused by misattributing recollection to a context other than the study list. In Experiments 1 and 2, false remember responses to distractors that were unrelated to studied words increased if they were encountered in a “preexposure” phase a few minutes or even a few days prior to the studied list. A third experiment demonstrated that remember responses to preexposed distractors increased when they were encoded in a manner similar to studied items, despite the more similar items being of weaker overall memory strength. We propose a source misattribution account of false remembering to explain these data, suggesting that all remember judgments reflect conscious recollection of contextual details, but false remember judgments are partly the result of recollection of details from an extralist context (i.e., from a source other than the study list).     

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.