An event-related potential study of the revelation effect

Event-related potentials (ERPs) were recorded during a verbal recognition memory task in order to investigate whether changes in familiarity are part of the explanation for the revelation effect. For half of the test words, participants solved an anagram prior to making the old/new recognition judgment. A revelation effect was obtained: When test words were preceded by the anagram task, a higher probability of an old response was associated with the items than was otherwise the case. The ERPs recorded time-locked to the onset of the test words were separated according to old/new status andthe presence/absence of the anagram task. The ERP index of familiarity was of lower amplitude for both old and new items that were preceded by the anagram task. These findings are consistent with the view that part of the explanation for the revelation effect is a reduction in the familiarity of the critical test items.     

The revelation effect for item and associative recognition: Familiarity versus recollection

The revelation effect occurs when items on a recognition test are more likely to be judged as being old if they are preceded by a cognitive task that involves the processing of similar types of stimuli. This effect was examined for item (single-word) and associative (word-pair) recognition. We found, in Experiments 1 and 2, a revelation effect for item, but not for associative recognition under normal study conditions. A revelation effect for both item and associative recognition was observed in Experiments 3 and 4 when study time was extremely brief, thus limiting the encoding of information that would support recall or recollection. In Experiment 5, we demonstrated that the revelation effect for item recognition is eliminated when item recognition decisions are made in the context of a study item. The results show that the revelation task influenced recognition decisions based on familiarity, but not decisions that involved recall or recollection.     

Event-related potential evidence for multiple causes of the revelation effect

Asking people to discover the identity of a recognition test probe immediately before making a recognition judgment increases the probability of an old judgment. To inform theories of this "revelation effect," event-related potentials (ERPs) were recorded for revealed and intact test items across two experiments. In Experiment 1, we used a revelation effect paradigm where half of the test probes were presented as anagrams (i.e., a related task) and the other items were presented intact. The pattern of ERP results from this experiment suggested that revealing an item decreases initial familiarity levels and caused the revealed items to elicit similar levels of activity. In Experiment 2, half of the probes were preceded by an addition task (i.e., an unrelated task). The pattern of ERP effects in this study were distinct from those observed in Experiment 1. More specifically, revealed item ERPs were more negative than intact ERPs at frontal electrodes and more positive at parietal electrodes early in the interval. Later in the epoch, revealed item ERPs were more negative than intact items. These data suggest that related tasks decrease familiarity and alter the signal-to-noise ratio of old and new items, whereas unrelated tasks affect processing in a different way (perhaps by changing decision processes) that also results in the revelation effect. The implications for current theories of the revelation effect are discussed.     

Does familiarity change in the revelation effect?

The revelation effect describes the increased tendency to call items "old" when a recognition judgment is preceded by an incidental task. Past findings show that d' for recognition decreases following revelation, evidence that the revelation effect is due to familiarity change. However, data from receiver operating characteristic curves from 3 experiments produced no evidence of changes in recognition sensitivity. The authors illustrate how the use of a single-point measure like d' can be misleading when familiarity distribution variances are unequal. Also investigated was whether the effect depends on the revelation materials used. Neither the memorability of the revelation items, their similarity to recognition probes, nor the difficulty of the task changed the size of the effect. Thus, the revelation effect is not the result of a memory retrieval mechanism and seems to be generic and all-or-nothing. These characteristics are consistent with response bias rather than familiarity change.     

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.     

The effect of the feeling of resolution and recognition performance on the revelation effect

The fact that engaging in a cognitive task before a recognition task increases the probability of “old” responses is known as the revelation effect. We used several cognitive tasks to examine whether the feeling of resolution, a key construct of the occurrence mechanism of the revelation effect, is related to the occurrence of the revelation effect. The results show that the revelation effect was not caused by a visual search task, which elicited the feeling of resolution, but caused by an unsolvable anagram task and an articulatory suppression task, which did not elicit the feeling of resolution. These results suggest that the revelation effect is not related to the feeling of resolution. Moreover, the revelation effect was likely to occur in participants who performed poorly on the recognition task. The result suggests that the revelation effect is inclined to occur when people depend more on familiarity than on recollection process.     

Altering the balance of recollection and familiarity influences the revelation effect

The revelation effect occurs when recognition test probes are more likely to be called "old" if they are preceded by a verbal processing task. Two experiments examined the role of familiarity and recollection in producing this effect. Each experiment tested the hypothesis that decreasing recollection would heighten the magnitude of the revelation effect. In Experiment 1, the revelation effect increased by delaying the recognition test. In Experiment 2, the revelation effect increased when the presentation rate of the study words was reduced. These results are discussed in terms of the variables that produce the revelation effect in episodic and nonepisodic memory judgments.     

Interrupting recognition memory: Tests of familiarity-based accounts of the revelation effect

The revelation effect is a puzzling phenomenon in which items on a recognition test are more likely to be judged as "old" when they are immediately preceded by a problem-solving task, such as anagram solution. The present experiments were designed to evaluate Westerman and Greene's (1998) and Hicks and Marsh's (1998) familiarity-based accounts of this effect. We found comparable revelation effects when probes were preceded by an anagram or a numerical addition task and when subjects performed either one or two of these tasks. Taken together, the results do not support familiarity-based accounts of the revelation effect but are consistent with a proposed decision-based interpretation (i.e., criterion flux), in which it is assumed that the revelation task displaces the study list context in working memory, leading subjects to adopt a more liberal recognition decision criterion, thereby increasing the hit and false alarm rates.     

Judgments of remembering: the revelation effect in children and adults

When items on a recognition test are presented as a series of increasingly complete fragments rather than being presented initially in their fully intact form, adults' judgments of recognition exhibit an increased tendency to judge items as "old," an illusion of recognition referred to as the revelation effect. The present study used pictorial stimuli to test for a revelation effect with 4-year-olds, 8-year-olds, and adults (N = 76). A reliable revelation effect was found at all ages tested, indicating that the complex fluency-of-processing discrepancy detection and attribution mechanisms thought to be responsible for the effect function similarly across an age range from 4-years-of-age through adulthood. It was also found that the recognition decisions of the 8-year-olds and the adults were affected by how quickly they were able to identify a picture during the revelation phase of the recognition test. This effect was not found with the 4-year-olds, suggesting an age difference in the awareness and strategic use of an implicit memory effect when making explicit judgments of recognition.     

流畅性对再认的影响:实验证据及理论解释

流畅性可以影响再认,而且仅影响熟悉性加工的观点已得到大量研究的证实。近年一些研究者采用掩蔽启动范式并结合修改的R/K范式、独立判断的R/K范式等实验范式,操控测验项目的流畅性,发现流畅性影响的可能是猜测或者回想加工,因而质疑这个结论。为解释流畅性对再认的影响,流畅性归因理论侧重对流畅性的归因、冲突-归因理论侧重期待流畅性和实际流畅性之间的冲突、预激活-适应模型侧重启动刺激引起的神经活动激活或适应、线索-学习理论侧重流畅性线索的有效性。未来研究应关注流畅性对来源和联结记忆的影响,并考察流畅性对再认的影响在不同年龄人群或遗忘症人群中的表现是否一致。     

Revelation without presentation: Counterfeit study list yields robust revelation effect

This study explores the revelation effect, a recognition memory phenomenon that occurs when test items (or related items) are specially processed before recognition judgment. These revealed items, whether targets or lures, receive a positive response bias. Although the effect occurs across various conditions, it has not been shown to occur when participants make judgments unrelated to episodic memory. We investigated whether the effect would occur when a recognition decision was nominally one of episodic memory, but when a complete episodic event had not occurred. Specifically, participants listened to noise that allegedly masked a list of words (in fact, no words existed). A revelation effect occurred with this pseudo-subliminal procedure, suggesting that the revelation effect need not rely on stimuli recalled through episodic memory but only a specific event to recall. The effect did not occur when participants simply guessed whether words were on an unheard list or made semantic judgments.     

A test of two different revelation effects using forced-choice recognition

The revelation effect refers to the finding of an increased propensity to classify recognition test probes as old when they are preceded by a problem solving task. Recent research indicates that revelation effects are dissociable based on whether the revelation task involves an item that is the same as or different than the subsequently presented recognition probe. Using a two-alternative forced-choice design, we found a revelation effect for both words (Experiment 1) and nonwords (Experiment 2) in the condition where the revealed item was the same as the target item (same revelation condition), but no effect when the revealed item was different than either test alternative (different revelation condition). These results were replicated using a mixed list design containing both words and nonwords (Experiment 3). Results support Verde and Rotello’s (2004) two-factor account of the revelation effect, which proposes that changes in memory sensitivity underlie revelation effects in the same revelation condition, and that changes in the decision criterion are responsible in the different revelation condition.     

ROC curves show that the revelation effect is not a single phenomenon

The revelation effect describes the increased tendency to call itemsold when a recognition judgment is preceded by an incidental task. In theory, the effect could come about either from a more liberal response bias or from a change in underlying memory sensitivity. Using analyses of receiver-operating characteristic curves, we show that the revelation effect occurs for each of these reasons, but under different empirical conditions. A shift in response bias fully accounts for the revelation effect when revealed items are unrelated to the subsequent recognition probes. However, a change in memory sensitivity contributes to the effect when revealed items are identical to the recognition probes. Thus, the revelation effect encompasses at least two distinct phenomena.     

Recognition memory for source and occurrence: The importance of recollection

Previous recognition memory studies indicate that when both recollection and familiarity are expected to contribute to recognition performance (e.g., discriminating studied items from nonstudied items) the dual-process and the unequal-variance signal detection models provide comparable accounts of performance. When familiarity is not expected to be useful (e.g., when items from two equally familiar sources are discriminated between), the dual-process model provides a significantly better account of performance. In the present study, source recognition was tested under conditions in which familiarity could have been used to perform a list-discrimination task; participants were required to discriminate between strong studied items, weak studied items, and new items. The dual-process model provided a better account of performance than did the unequal-variance model. Moreover, the results indicated that the unequal-variance assumption in a single-process signal detection model was not a valid substitution for recollection and that recollection was used to make recognition judgments even when assessments of familiarity were useful.     

Illusions of familiarity caused by cohort activation

Subjects took part in an auditory lexical decision task followed by an auditory test of recognition memory for words presented in this task. Subjects categorized their recognition judgments as based on either recollection (“remember” responses) or familiarity (“know” responses). Distractor items in the recognition test included the base words from which the nonwords used in the lexical decision task were derived. Consistent with the findings of Wallace, Stewart, Sherman, and Mellor (1995), more false alarms were made to “late” base words (where the corresponding nonwords were created by changing a phoneme near the end of the word) than to “early” base words (corresponding nonwords were created by changing a phoneme at the beginning of the word). However, this effect was found in “know” responses but not in “remember” responses. The findings are attributed to enhanced fluency with which the base words are processed following their implicit activation at encoding.     

The role of familiarity in item recognition, associative recognition, and plurality recognition on self-paced and speeded tests

Four experiments compare the effect of familiarity on item, associative, and plurality recognition on self-paced and speeded tests. The familiarity of test items was enhanced by presenting a prime that matched the subsequent test item. On item and plurality recognition tests, participants were more likely to respond "old" to primed than to unprimed test items. In associative recognition, priming increased the proportion of old responses on a speeded test, but not on a self-paced test. This suggests that familiarity plays a larger role in item and plurality recognition than in associative recognition on self-paced tests. On speeded tests, priming has a similar effect on item, associative, and plurality recognition. Results suggest that item and associative recognition rely differentially on familiarity and recollection. They are also consistent with recent evidence suggesting that different processes underlie plurality and associative recognition.     

Interrupting recognition memory: Tests of a criterion-change account of the revelation effect

The revelation effect is evidenced by an increase in positive recognition responses when the test probe is immediately preceded by an unrelated problem-solving task. As an alternative to familiarity-based explanations of this effect (Hicks & Marsh, 1998; Westerman & Greene, 1998), Niewiadomski and Hockley (2001) proposed a decision-based account in which it is assumed that the problem-solving task displaces the study list context in working memory, leading subjects to adopt a more liberal recognition criterion. In the present study, we show that the revelation effect is seen when the stimulus materials are pure lists of very rare words or nonwords. In contrast, for mixed lists of common words and very rare words or nonwords, the revelation effect is found for common words but disappears for very rare words and nonwords. We argue that, in mixed lists, the liberal decision bias following the revelation task and the criterion changes between common words and very rare words and nonwords serve to offset each other.     

False recognition across meaning,language, and stimulus format: Conceptual relatedness and the feeling of familiarity

Four experiments examined contributions of conceptual relatedness and feelings of familiarity to false recognition. Participants first studied lists of unrelated items (e.g., table, lock) followed by a recognition test with three types of items: (1) studied items (e.g., table), (2) semantically related lures (e.g., key), and (3) unrelated lures (e.g., cup). Participants falsely recognized more related than unrelated lures when the stimuli were words (Experiment 1A) and pictures (Experiment 1B), when the studied items and related lures differed in language (Experiment 2), and when they differed in perceptual format (Experiment 3). In Experiment 4, an attribution manipulation, designed to make feelings of familiarity nondiagnostic for memory judgments, eliminated the false-recognition effect obtained in Experiment 3. Overall, the study suggests that conceptual relatedness produces false recognition even in the absence of shared perceptual surface features between study and test items, and it does so by generating feelings of familiarity.     

Age-Related Differences in Memory Illusions: Revelation Effect

Older adults are often more susceptible to various illusions and distortions of memory than young adults. In the experiments reported here, we explored the question of whether normal aging was associated with a larger revelation effect, an illusion of memory in which items that are revealed gradually during a recognition test are more likely to be called old than unrevealed items that are shown in their entirety. Contrary to expectations, older adults were not susceptible to this memory illusion. A revelation effect occurred for young but not older adults, even when older adults were similar to young adults on measures of recognition and repetition priming. When data across experiments were combined, there was evidence for a negative revelation effect in older adults in which revealed items were less likely called old than unrevealed items. These results place boundary conditions on the claim that older adults are more susceptible than young adults to memory illusions, and imply that one or more mechanisms underlying the revelation effect are age sensitive.     

List strength effect without list length effect in recognition memory

The study of list length effects (adding items to a list affects memory for the other items) and list strength effects (strengthening some items in a list affects memory for the nonstrengthened items) is important to constrain models of memory. In recognition memory, a list length effect is generally found, whereas a list strength effect is not. Using the switched-plurality procedure in an old-new recognition task (e.g., study banana; test bananas), we found the opposite pattern. Length manipulations caused no change in memory performance, whereas strength manipulations did. The list strength effect was found when recollection was likely to operate at test (with switched-plurality lures). When recollection was unlikely to operate (with unrelated lures), the strength effect disappeared. The result was observed using both a size judgement task (which has previously produced positive list strength effects) and a pleasantness judgement task (which has not yielded list strength effects before).