Repetition blindness in rapid lists: activation and inhibition versus construction and attribution

The authors examine the repetition blindness effect--the failure to report one of the occurrences of a word presented twice in a rapid list. This phenomenon has been ascribed to inhibitory processes that prevent immediate tokenization of the 2nd occurrence of a repeated word. The authors present several kinds of evidence against that account, including observations that repetition blindness (a) does not occur when repetitions are not embedded in a list of familiar orthographic units, (b) is alleviated by precuing the subject with the identity of the word that may repeat within a rapid list, and (c) can be caused by cues presented after the list, when the opportunity for inhibition has passed. It is proposed that repetition blindness can better be understood through the principles of construction and attribution.     

Repetition deficits, list context, and word-class interactions in the RSVP of words in sentences.

We report a failure to find a repetition deficit in recall following the rapid serial visual presentation (RSVP) of words within sentences, using adjectives rather than nouns as the critical items. In a series of experiments that ruled out participant and procedural differences as the source of the failure, both word class and list context were found to moderate the repetition deficit, but grammatical necessity did not. The presence in the list of sentences in which the repeated adjectives were separated by more than three words (i.e., more than 400 ms in RSVP) not only eliminated the repetition deficit for the recall of those sentences but also for the recall of sentences in which the repeated adjectives were separated by three or fewer words (i.e., less than 400 ms in RSVP). However, although substantially reduced, a repetition deficit with noun-based materials was still found in this list context. Matching the adjective-based sentences with the noun-based sentences in sentence length and position of the critical items revealed that the moderating effect of word-class on the repetition deficit was mediated by the biases in sentence structure that using different word classes tend to induce.     

Repetition blindness and homophone blindness in young and older adults

We tested age effects on repetition blindness (RB), defined as the reduced probability of reporting a target word following presentation of the same word in a rapidly presented list. We also tested age effects on homophone blindness (HB), in which the first word is a homophone of the target word rather than a repeated word. Thirty young and 28 older adults viewed rapidly presented lists of words containing repeated, homophone, or unrepeated word pairs and reported all of the words immediately after each list. Older adults exhibited a greater degree of RB and HB than young adults using a conditional scoring method that provides certainty that blindness has occurred. The existence of RB and HB for both age groups, and increased blindness for older compared to young adults, supports predictions of a binding theory that has successfully accounted for a wide range of phenomena in cognitive aging.     

Remembering changes: repetition effects in face recollection.

Two experiments examined effects of repetition and change on states of awareness in face recognition. Participants studied repeatedly presented photographs of faces, with the second presentation following either immediately after the first presentation (massed repetition) or following six intervening items (spaced repetition). To manipulate perceptual change, each repeated face was either identical or a mirror image of the first presentation. Subsequently, when recognising a face, participants indicated whether they consciously recollected its prior occurrence ("remembering") or recognised it on the basis of familiarity ("knowing"). Changes in appearance between repeated faces enhanced remember, but not know, responses, and these effects were accentuated for spaced, rather than massed, repetition. These findings suggest that distinctiveness of encoding supports the phenomenological experience of conscious remembering.     

Reverse “repetition blindness” and release from “repetition blindness”: Constructive variations on the “repetition blindness” effect

N. Kanwisher observed that subjects shown rapid lists of words recall two occurrences of a repeated word less often than two unrelated words. Kanwisher explained this repetition blindness through a type/token account, which assumes that encoding the second occurrence of a repeated word is inhibited if it occurs too soon after the first. More fundamentally, it assumes that failure to recall a word from a rapid list results from failure to encode its occurrence. Contrary to that interpretation, we observed that subjects can often recognize words that they cannot recall from a rapid list. We also observed reverse repetition blindness, when the second presentation was given greater contextual support, and a release from repetition blindness effect, when distinctive contextual support was given to each occurrence. We concluded that a constructive account of remembering provides a better explanation of all of the effects.     

Event-related brain potentials dissociate repetition effects of high-and low-frequency words

Event-related brain potentials (ERPs) were recorded while subjects detected nonwords interspersed among sequences of words of high or low frequency of occurrence. In Phase 1, a proportion of the words were repeated after six intervening items. In Phase 2, which followed after a break of approximately 15 min, the words were either repeats of items presented in the previous phase or new. Unrepeated low-frequency words evoked larger N400 components than did high-frequency items. In Phase 1, this effect interacted with repetition, such that no frequency effects were observed on N400s evoked by repeated words. In addition, the post-500-msec latency region of the ERPs exhibited a substantial repetition effect for low-frequency words, but did not differentiate unrepeated and repeated high-frequency words. In Phase 2, ERPs evoked by "old" and "new" high-frequency words did not differ in any latency region, while those evoked by old and new low-frequency words differed only after 500 msec. The interactive effects of frequency and repetition suggest that these variables act jointly at multiple loci during the processing of a word. The specificity of the post-500-msec repetition effect for low-frequency words may reflect a process responsive to a discrepancy between words' intra and extraexperimental familiarity.     

Repetition blindness for words yet repetition advantage for nonwords

Accuracy of report of words in a rapidly presented sequence is reduced if 1 word is a repetition of a previous word. This is repetition blindness. If, however, the items are pronounceable nonwords, or pseudohomophones, repetition improves recall. A repetition advantage for nonwords also occurs when subjects merely count the items or when the item between the critical nonwords is a familiar word. Familiarizing subjects with the nonwords improved the level of recall but did not affect the repetition advantage. These results are considered in relation to token individuation and other accounts of repetition blindness. The findings suggest that for identical linguistic stimuli the types bound to episodic memory tokens that are vulnerable to repetition blindness are lexical units.     

重复知盲效应产生的机制——来自汉语叠词加工的证据

以汉语中的叠词为实验材料,对重复知盲产生机制的类型标记个体化理论和建构理论进行检验。采用RSVP研究范式,在两个实验中让178名被试口头报告列表中出现的所有汉字（全部报告）或列表中最后两个字（部分报告）。结果发现：（1）在呈现速率为128ms和198ms时,完全重复的汉字在全部报告和部分报告任务中均存在RB效应,但在部分报告任务下出现的RB相比全部报告任务的减少了,符合建构理论的假设。（2）在全部报告条件下,不仅重复刺激的正确报告率会降低,而且与重复刺激相关的非重复刺激的正确报告率也会降低。研究表明建构理论比类型标记个体化理论更能解释RB效应的产生机制。     

The effects of specific and categorical orienting on children's incidental and intentional memory for pictures and words

This study examines the effects of differences in the encoding of specific and categorical information on second graders' (7 years; 7 months), fifth graders' (10; 6), and college adults' cued recall for cue-target picture and word pairs. The cues at retrieval were either same-modal (P-P and W-W) or cross-modal (P-W and W-P) as the cues presented in acquisition, and acquisition encoding was either incidental or intentional and constrained by orienting questions or unconstrained. The most important results were that both picture and word recall varied with the encoding of both specific and categorical information and that children differed from adults in the encoding of both kinds of information in both incidental and intentional encoding conditions. In addition, both children and adults showed congruency effects for pictures and words that were greater for specific than for categorical orienting questions. The results suggest that differences in the encoding of both specific and categorical attribute information contribute to developmental recall differences independently of encoding intent and stimulus modality.     

Calling all codes: interactive effects of semantics, phonology, and orthography produce dissociations in a repetition blindness paradigm

We used the repetition blindness (RB) paradigm to examine the roles of semantics, phonology, and orthography on report from rapidly presented 5-item word lists. Semantic primes in positions 1 and 3 in the list preceded homographic homophones, homographic heterophones, and heterographic homophones as critical targets in positions 2 and 4. All codes (i.e., semantic, phonologic, and orthographic) were repeated, or meaning changed while only phonology, only orthography, or both were repeated for the critical targets. Using a scoring procedure that considered order of report, we assessed facilitation for report of the first instance of the repeated target (a novel aspect of our procedure) and RB for report of the second instance of the repeated target. Except when accompanied by a change in orthography, a change in meaning reduced RB relative to when all codes were repeated. Facilitation in the report of the first instance of the repeated item occurred only if meaning changed and phonology was repeated (independent of whether orthography changed). Finally, recall was worse for the meaning change nonrepeated control lists (which instantiated 3 unrelated meanings in the list, including the last unrelated item) than for the no-meaning change control lists (which instantiated 2 unrelated meanings). We discuss the relevance of these findings for extant accounts of repetition blindness.     

How is the serial order of a verbal sequence coded? Some comparisons between models

Current models of verbal short-term memory (STM) propose various mechanisms for serial order. These include a gradient of activation over items, associations between items, and associations between items and their positions relative to the start or end of a sequence. We compared models using a variant of Hebb's procedure in which immediate serial recall of a sequence improves if the sequence is presented more than once. However, instead of repeating a complete sequence, we repeated different aspects of serial order information common to training lists and a subsequent test list. In Experiment 1, training lists repeated all the item-item pairings in the test list, with or without the position-item pairings in the test list. Substantial learning relative to a control condition was observed only when training lists repeated item-item pairs with position-item pairs, and position was defined relative to the start rather than end of a sequence. Experiment 2 attempted to analyse the basis of this learning effect further by repeating fragments of the test list during training, where fragments consisted of either isolated position-item pairings or clusters of both position-item and item-item pairings. Repetition of sequence fragments led to only weak learning effects. However, where learning was observed it was for specific position-item pairings. We conclude that positional cues play an important role in the coding of serial order in memory but that the information required to learn a sequence goes beyond position-item associations. We suggest that whereas STM for a novel sequence is based on positional cues, learning a sequence involves the development of some additional representation of the sequence as a whole.     

Enhancement of 4-year-old children's memory span for phonologically similar and dissimilar word lists

Previous research suggests that preschool children are deficient in rehearsal and that stimulus list repetitions can improve their recall, presumably by substituting for the products of rehearsal. However, the previous research included interitem or postlist retention intervals of several seconds or more. We examined the utility of list repetitions with reference to an ordinary span task in which spoken words were presented 1 s apart for immediate recall. Lists with phonologically similar versus dissimilar items were included, to determine if the overall pattern of recall could be made more similar to what is ordinarily obtained in older children. Cumulative repetition was found to cause a moderate increase in both memory span and the phonological similarity effect. Other types of list repetition provided more insight into types of stimulus redundancy that were helpful (e.g., repeated serial order information) or not helpful (e.g., forced articulatory coding) to children attempting to recall spoken lists. The underlying mnemonic processes are discussed.     

Evidence from the attentional blink for different sources of word repetition effects

T2 in an attentional blink paradigm served as a high- or low-frequency prime word for a subsequent repeated target. Consistent with research in visual word identification, only reported primes facilitated the identification of a target repeated approximately 8 s after RSVP. Priming was greater for low- than high-frequency words. Analogous with masked priming, a blinked T2 facilitated report of a repeated target occurring 318 ms after T2 in RSVP. The blinked repetition priming effect was additive with target frequency. These results indicate that: (1) the outcomes of processing prime words are a key factor in repetition priming effects, with blinked and reported T2s behaving like masked and unmasked primes, respectively, (2) there may be different sources of repetition effects, (3) there is a consistent cross-paradigm pattern of repetition effects that occurs as a function of prime–target interval and the ability to identify the word on its first and second presentation.     

Neuroanatomical correlates of category-specific semantic disorders: A critical survey

Current models of verbal short‐term memory (STM) propose various mechanisms for serial order. These include a gradient of activation over items, associations between items, and associations between items and their positions relative to the start or end of a sequence. We compared models using a variant of Hebb's procedure in which immediate serial recall of a sequence improves if the sequence is presented more than once. However, instead of repeating a complete sequence, we repeated different aspects of serial order information common to training lists and a subsequent test list. In Experiment 1, training lists repeated all the item–item pairings in the test list, with or without the position–item pairings in the test list. Substantial learning relative to a control condition was observed only when training lists repeated item–item pairs with position–item pairs, and position was defined relative to the start rather than end of a sequence. Experiment 2 attempted to analyse the basis of this learning effect further by repeating fragments of the test list during training, where fragments consisted of either isolated position–item pairings or clusters of both position–item and item–item pairings. Repetition of sequence fragments led to only weak learning effects. However, where learning was observed it was for specific position–item pairings. We conclude that positional cues play an important role in the coding of serial order in memory but that the information required to learn a sequence goes beyond position–item associations. We suggest that whereas STM for a novel sequence is based on positional cues, learning a sequence involves the development of some additional representation of the sequence as a whole.     

Very clever homunculus: Compound stimulus strategies for the explicit task-cuing procedure

In two experiments, subjects were given arbitrary letter cues or meaningful word cues that specified the task to be performed on a subsequent target stimulus. Letter and word cues were presented in separate blocks. There were two cues of each type for each task. Three kinds of transitions separated tasks:cue repetitions, in which both the cue and the task repeated;task repetitions, in which the cue changed but the task repeated; andtask alternations, in which both the cue and the task changed. Responses were faster for cue than for task repetitions for both cue types. With word cues, task repetitions were not reliably faster than task alternations. With letter cues, task repetitions were reliably faster than task alternations in the first block but not in the second block. The results suggest that subjects responded to the compound of the cue and the target rather than switching task set between trials.     

Illusory words created by repetition blindness: a technique for probing sublexical representations

When two orthographically similar words are displayed using rapid serial visual presentation (RSVP), the repeated letters in the second critical word (W2) are not detected, leading to a deficit in reporting this word, a phenomenon known as repetition blindness (RB). The unrepeated letters in W2 do appear to be detected and available to feed activation to words compatible with them (Morris & Harris, 1999). When a fragment was strategically placed in the RSVP stream, as in GROW throw ank, observers reported seeing thank more often than in the control condition BEAT throw ank. Illusory words were facilitated by repetition blindness only when the recombining letters maintained their position in the words. Illusory word report was insensitive to the phonological similarity of the recombining letters; equal quantities of illusory words were created by sequences like china CHEAT THR (-->threat) and swung SWEAT THR (-->threat). In addition to being an interesting phenomenon in its own right, the illusory words paradigm may have considerable use as a tool for probing the perceptual units underlying visual word recognition.     

Effects of orienting task,spacing of repetitions,and list context on judgments of frequency

Subjects were given an unexpected frequency judgment test following a list of words in which items were presented either two, three, and five times or three, five, and seven times, with a spacing of 0, 2, 16, or 32 items between repetitions. During list presentation, they either rated the imagery value of each word or made continuous frequency estimates. Postlist frequency judgments of words presented three and five times were higher for the list containing words of Frequency 7, and judgments were also higher following the imagery rating task. Continuous judgments were unaffected by the list context and showed different effects of spacing than postlist judgments. The results provide support for the operation of response bias factors in the frequency judgment task and are relevant to theoretical interpretations of the spacing effect.     

Aging and memory for words and action events: effects of item repetition and list length

We were concerned with the effects of item repetition, list length, and class of item on free recall in elderly as compared with young adults. In Experiment 1, samples of young and elderly adults recalled a list of 27 words and a list of 27 action events (minitasks performed by the subjects). Some items were presented once and some twice. Although the younger subjects showed better recall on both types of lists, the older sample benefited from item repetition as much as did the younger sample. This finding was replicated in Experiment 2. A second finding in Experiment 2 was a significant aging effect in the recall of long but not of short lists of both words and action events. The absence of an Age X Repetition Effect interaction was ascribed to the strength nature of the repetition manipulation. The age effects in the recall of the long lists were attributed to possible deficits in retrieval proficiency.     

Two scenes or not two scenes: The effects of stimulus repetition and view-similarity on scene categorization from brief displays

Previous research suggests that understanding the gist of a scene relies on global structural cues that enable rapid scene categorization. This study used a repetition blindness (RB) paradigm to interrogate the nature of the scene representations used in such rapid categorization. When stimuli are repeated in a rapid serial visual presentation (RSVP) sequence (~10 items/sec), the second occurrence of the repeated item frequently goes unnoticed, a phenomenon that is attributed to a failure to consolidate two conscious episodes (tokens) for a repeatedly activated type. We tested whether RB occurs for different exemplars of the same scene category, which share conceptual and broad structural properties, as well as for identical and mirror-reflected repetitions of the same scene, which additionally share the same local visual details. Across 2 experiments, identical and mirror-image scenes consistently produced a repetition facilitation, rather than RB. There was no convincing evidence of either RB or repetition facilitation for different members of a scene category. These findings indicate that in the first 100–150 ms of processing scenes are represented in terms of local visual features, rather than more abstract category-general features, and that, unlike other kinds of stimuli (words or objects), scenes are not susceptible to token individuation failure.     

Acute alcohol effects on repetition priming and word recognition memory with equivalent memory cues

Acute alcohol intoxication effects on memory were examined using a recollection-based word recognition memory task and a repetition priming task of memory for the same information without explicit reference to the study context. Memory cues were equivalent across tasks; encoding was manipulated by varying the frequency of occurrence (FOC) of words in the study lists. Twenty-two female and male social drinkers (age 21-24 years) completed equivalent versions of the memory tasks in two counterbalanced sessions (alcohol challenge, no-alcohol). Alcohol and the FOC manipulation affected recollection-based memory processing, but not repetition priming. Results supported alcohol's dissociative effects on memory systems.