Additive and interactive effects of word frequency and masked repetition in the lexical decision task

In previous studies, additive effects of masked repetition and word frequency on lexical decision latency have been reported. This additive pattern was replicated in Experiment 1 with the use of lowfrequency words (range, 1–7 per million) selected at random. In contrast, in Experiment 2, in which low-frequency words known to be familiar to the subjects were used, the masked repetition priming effect was greater for low-frequency than for high-frequency words. It is suggested that the absence of an interaction between masked repetition and frequency observed in previous studies and in the present Experiment 1 was due to the fact that very-low-frequency words often have an unstable representation in the subjects’ lexicon and, consequently, sometimes fail to produce repetition priming effects in full.     

Modeling the effects of repetition and word frequency in perceptual identification

The counter model for word identification (Ratcliff & McKoon, 1997) has been challenged by recent empirical findings that performance on low-frequency words improves as the result of repetition of the words. We show that the model can accommodate this learning effect, and that it can do so without jeopardizing its explanations of the effects on word identification of a large number of other variables.     

Accessing lexical memory: The transfer of word repetition effects across task and modality

Reading by literate adults is generally assumed to represent skill acquired years earlier. However, the present experiments show that aspects of that skill can be readily modified. In two experiments, pronunciation of visually presented common words speeded later recognition of those words. This facilitation of recognition occurred although subjects did not expect word repetition and the task was changed from pronunciation to recognition. In contrast, naming pictures did not facilitate later recognition of visually presented picture names. The occurrence of facilitation when the task was changed and the lack of facilitation when stimulus format was changed suggest that facilitation occurs in the processes of encoding and accessing memory, processes that may change little across tasks but may change substantially with stimulus format changes. This facilitation of recognition occurs automatically without mediation by subjects’ expectations. A third experiment indicates that this facilitation of recognition shows little relation to episodic memory.     

Abstractionist versus episodic theories of repetition priming and word identification

This paper reviews research relevant to the question of whether words are identified through the use of abstract lexical representations, specific episodic representations, or both. Several lines of evidence indicate that specific episodes participate in word identification. First, pure abstractionist theories can explain short-term but not long-term repetition priming. Second, long-term repetition priming is sensitive to changes in surface features or episodic context between presentations of a word. Finally, long-term priming for pseudowords is also difficult for pure abstractionist theories to explain. Alternative approaches to word identification are discussed, including both pure episodic theories and theories in which both episodes and abstract representations play a role.     

Cognitive effort and the word frequency effect in recognition and lexical decision

Cognitive effort requirements for high and low frequency words were assessed during study for a recognition test and during the performance of a lexical decision task. Recognition for these words was tested following each task. Low frequency words received greater effort than high frequency words during study for recognition, and these words were subsequently recognized better than high frequency words. Cognitive effort requirements during performance of an incidental lexical decision task were similar to those during study for recognition. Moreover, recognition performance following the lexical decision task resembled performance following a recognition expectancy. Overall, the results indicate that low frequency words require more extensive processing than high frequency words and that this difference in processing may be a factor in recognition word frequency effects.     

Stimulus and response contributions to the children's reaction-time repetition effect

Adults and 8-, 10-, 12-, and 14-year olds completed a serial reaction-time task with two stimuli mapped to each of two responses and 100-, 500-, and 1000-msec response-stimulus intervals (RSIs). Trials were classified as (1) identical (same stimulus and same response on two consecutive trials), (2) response equivalent (different stimulus but same response on two consecutive trials), or (3) different (different stimulus and different response on two consecutive trials). Identical and different trials were compared as a general indication of repetition effects. Response-equivalent minus identical reaction time identified stimulus contributions, and different minus response-equivalent reaction time identified response contributions. Adults received a repetition advantage at all RSIs and children received a repetition advantage at 500- and 1000- but not 100-msec RSIs. Stimulus contributions accounted for the repetition effect for both adults and children. At the 500- and 1000-msec RSIs, both the overall repetition effect and stimulus contribution were positive and decreased in magnitude as age increased. The response contribution was independent of RSI and was negative for 8- and 10-year-olds and near zero or positive for older performers. At the longer RSIs, positive stimulus contributions were sufficient to overcome the negative response contributions present for younger children.     

Rapid word identification in pure alexia is lexical but not semantic

Following the notion that patients with pure alexia have access to two distinct reading strategies-letter-by-letter reading and semantic reading-a training program was devised to facilitate reading via semantics in a patient with pure alexia. Training utilized brief stimulus presentations and required category judgments rather than explicit word identification. The training was successful for trained words, but generalized poorly to untrained words. Additional studies involving oral reading of nouns and of functors also resulted in improved reading of trained words. Pseudowords could not be trained to criterion. The results suggest that improved reading can be achieved in pure alexia by pairing rapidly presented words with feedback. Focusing on semantic processing is not essential to this process. It is proposed that the training strengthens connections between the output of visual processing and preexisting orthographic representations.     

Building permanent memory codes: codification and repetition effects in word identification

The studies presented in this article investigate the memory processes that underlie two phenomena in threshold identification: word superiority over pseudowords and the repetition effect (a prior presentation of an item facilitates later identification of that item). Codification (i.e., the development of a single memory code that can be triggered even by fragmented input information) explains the faster and more accurate identification of words than pseudowords. Our studies trace the development and retention of such codes for repeated pseudowords and examine the growth and loss of the repetition effect for both pseudowords and words. After approximately five prior occurrences, words and pseudowords are identified equally accurately in two types of threshold identification tasks, suggesting codification has been completed for pseudowords. Although the initial word advantage disappears, the accuracy of identification still increases with repetitions. The facilitation caused by repetition is not affected much by spacing within a session, but drops from one day to the next, and after a delay of one year has disappeared (new and old words were identified equally well). These results suggest an episodic basis for the repetition effect. Most important, after one year, performance is equal for old pseudowords and new and old words: all these levels are superior to that for new pseudowords, suggesting that the learned codes for pseudowords are as strong and permanent as the codes for words. A model of identification is presented in which feedback from codes and episodic images in memory facilitates letter processing. An instantiation of the model accounts for the major features of the data.     

In defense of abstractionist theories of repetition priming and word identification

There is a great deal of interest in characterizing the representations and processes that support visual word priming and written word identification more generally. On one view, these phenomena are supported by abstract orthographic representations that map together visually dissimilar exemplars of letters and words (e.g., the lettersA/a map onto a common abstract letter codea*). On a second view, orthographic codes consist in a collection of episodic representations of words that interact in such a way that it sometimes looksas if there are abstract codes. Tenpenny (1995) contrasted these general approaches and concluded by endorsing the episodic account, arguing that no evidence demands that we posit abstract orthographic representations. This review reconsiders the evidence and argues that a variety of priming and nonpriming research strongly supports the conclusion that abstract orthographic codes exist and support priming and word identification. On this account, episodic representations are represented separately from abstract orthographic knowledge and contribute minimally to these functions.     

Bias in masked word identification: unconscious influences of repetition priming

The beneficial influence of a prior study episode on subsequent identification of a word includes a large bias component, revealed in the forced-choice variant of the masked word identification test. In that type of test, subjects show a preference for a studied probe over a nonstudied probe, regardless of which one matches the masked target word. The forced-choice test was used in the present experiments to test the possibility that this bias effect is due to conscious recollection. Results show that bias was strongly attenuated (1) by changes in modality between study and test, and (2) under certain conditions, by using a conceptually driven study task. The bias effect was found only when probes were orthographically similar to one another, as predicted by the counter model (Ratcliff & McKoon, 1997). These results provide strong evidence that the bias effect is not mediated by conscious recollection.     

A transfer analysis of the repetition effect in the lexical and ambiguity decision tasks

Two experiments were performed in an attempt to evaluate explanations of repetition priming-the facilitation observed when the same word is processed a second time in the same task. One task employed was lexical decision (word/nonword) and the other was ambiguity decision (ambiguous/ unambiguous). In the first experiment, transfer on a lexical decision task was measured following either a lexical decision or an ambiguity decision. When the identical lists were processed in the first phase for lexical and ambiguity decision, equal repetition effects were obtained on lexical decision. However, when the ambiguity task was presented without nonwords, no repetition priming occurred. In a second experiment, the within-task repetition effect was large for the ambiguity decision, whereas no transfer was obtained from lexical decision to ambiguity decision. The results were interpreted as being consistent with a transfer-appropriate processing account of repetition priming.     

The word frequency effect in first- and second-language word recognition: A lexical entrenchment account

We investigate the origin of differences in the word frequency effect between native speakers and second-language speakers. In a large-scale analysis of English word identification times we find that group-level differences are fully accounted for by the individual language proficiency scores. Furthermore, exactly the same quantitative relation between word frequency and proficiency is found for monolinguals and three different bilingual populations (Dutch–English, French–English, and German–English). We conclude that the larger frequency effects for second-language processing than for native-language processing can be explained by within-language characteristics and thus need not be the consequence of “being bilingual” (i.e., a qualitative difference). More specifically, we argue that language proficiency increases lexical entrenchment, which leads to a reduced frequency effect, irrespective of bilingualism, language dominance, and language similarity.     

Controlling lexical contributions to the reading of pseudohomophones

Reynolds and Besner (2005) presented a computational account of six effects that emerge when readers are asked to pronounce pseudohomophones (nonwords—e.g., brane—that sound like words when pronounced). In the dual route cascaded (DRC) model of reading, they varied a parameter controlling the rate of inhibition from letter units to the orthographic lexicon to mimic strategic control over the extent of specific lexical processing. In this article, we provide an account in which the effects are simulated by varying the DRC’s reading-aloud criterion—a parameter that sets the minimal level of phonemic activation required to pronounce a letter string. We show that varying this parameter provides another means of controlling lexical contributions to reading aloud.     

The word frequency effect in recognition memory versus repetition priming

The role of word frequency in recognition memory and repetition priming was investigated by using a manipulation of attention. In Experiment 1, the lexical decision task produced greater repetition priming for low-frequency words than for high-frequency words following either the attended or the unattended study condition. The recognition memory test, on the other hand, showed a low-frequency word advantage only following the attended study condition. Furthermore, this advantage was limited to the measure of recognition memory based on conscious recollection of the study episode. In Experiment 2, a speeded recognition memory test replicated the pattern obtained with the unspeeded recognition memory test in Experiment 1. These results argue against the view that the word frequency effects in recognition memory and repetition priming have the same origin. Instead, the results suggest that the word frequency effect in recognition memory has its locus in conscious recollection.     

Episodic and semantic contributions to older adults' autobiographical recall

The authors examined episodic and semantic contributions to 2 salient features of older adults' autobiographical recall: the reminiscence bump and the retention effect. Forty well-educated and healthy older men (mean age = 72.5 years; SD = 1.1) recalled personal memories in response to a series of cue words. They also categorized each memory as something they remembered from the past (R response) or they knew had happened in the past (K response) and indicated their ages when each memory occurred. The authors assumed that R and K responses reflected the operation of the episodic and semantic memory systems, respectively. Results showed a reminiscence bump and a retention effect for both R and K responses. The authors discuss the implications of this finding concerning the purported bases of the reminiscence bump and the retention effect as well as the notion that aging is more likely to effect episodic memory than semantic memory.     

Orthographic contributions to perceived word center

We have a surprising tendency to misperceive the center of visually presented words (). To understand the origin of this bias, four experiments assessed the impact of letter font, letter size, and grapheme-phoneme convergences on perceived stimulus center. Fourteen observers indicated the perceived centers of words, pseudowords, consonant strings, and lines with a mouse cursor. Visual orthographic factors had no effect on perceived word center but grapheme-phoneme convergence did: Observers compensated for strong grapheme-phoneme asymmetries in the letter strings. These findings support the idea that the cognitive representation of words is spatially distorted as a result of lexical access mechanisms.     

Educational level and the word frequency effect: a lexical decision investigation.

It is known that speed and accuracy in recognizing words are constrained by the frequency of occurrence of these words ("frequency effect"). This study examines the relationship between educational level and the word frequency effect. We postulated that individual exposure to words that are rated lower in frequency tables should be greater among subjects with higher education and therefore hypothesized that the magnitude of the frequency effect should not be as marked within such a population as among subjects with a lesser educational level. A total of 40 neurologically healthy adults, half with an average of 18 years of formal education and the other half with an average of 11 years, participated in a lexical decision experiment. Results confirmed our hypothesis; that is, significant frequency effects on reaction times were obtained in both groups but this effect was of greater magnitude for the less educated as opposed to the more educated subgroup. The significance of this finding is discussed by reference to current models of word recognition.     

Testing the counter model for perceptual identification: Effects of repetition priming and word frequency

The counter model for perceptual identification (Ratcliff & McKoon, 1997) differs from alternative views of word recognition in two important ways. First, it assumes that prior study of a word does not result in increased sensitivity but, rather, in bias. Second, the effects of word frequency and prior study are explained by different mechanisms. In the present experiment, study status and word frequency of target and foil were varied independently. Using a forced-choice task, we replicated the bias effect. However, we also found several interactions between frequency and prior study that are in direct conflict with the counter model. Most important, prior study of both alternatives resulted in an attenuation of the frequency effect and an increase in performance for low-frequency targets, but not for high-frequency targets. These findings suggest that the effects of frequency and prior study are not mediated by completely independent mechanisms.     

Episodic memory reflected in printed word naming

Although memory is typically measured by recall or recognition, it is also expressed by fluent or stylized task performance. In this experiment, 12 volunteers (calledspeakers) completed four experimental stages over a 2-week period. They read printed words aloud in two sessions, before and after exposure to auditory training tokens. They later completed a recognition memory test, discriminating old from new words. Groups ofperceptual judges assessed the speakers vocal imitation by comparing utterances recorded before and after training and deciding which sounded like “better imitations” of the training tokens. The data showed clear evidence of postexposure imitation, with systematic effects that preclude strategic explanations. The contents of episodic memory were reflected by participants speaking style while they were reading aloud. Together, the imitation and recognition data suggest that memory preserves detailed traces of spoken words; those traces were apparently activated when participants later read the same words in the same context.     

Word-context effects in word naming and lexical decision

Stanovich and West (1983; West and Stanovich, 1982) demonstrated that lexical decisions to target words preceded by incongruous sentence contexts are inhibited more by these contexts than are naming responses to the same target words. They argued that this difference between the two tasks was due to post-lexical processing at the message level that is effective only in the lexical-decision task. The operations of the mechanism thought to underlie this post-lexical effect also predict that, under certain circumstances, the processing of target words congruous with the sentence context should be facilitated more in lexical decision than in naming. The present naming study together with an earlier lexical-decision study tested and confirmed this prediction for word targets following word contexts. The stimulus-onset asynchrony of context word and target word was also varied. This manipulation clearly affected the magnitude of facilitation, indicating that context-induced attentional processing can facilitate lexical access in word-context studies.