A bias in favor of the positive response to high-frequency words in recognition memory

A relatively liberal response bias for high-frequency words and a violation of the mirror effect for hit and false-alarm rates were found in a yes-no recognition-memory test. Subjects more frequently responded "old" to high-frequency words than to low-frequency words. Four experiments were conducted to determine the causes of the different response biases and of the violation of the mirror effect. The word-frequency effect on hit rates did not appear, whereas the false-alarm rate for low-frequency words was lower than that for high-frequency words. When low- or high-frequency words were presented separately in distinct halves of a recognition-memory test, the relatively liberal response bias for high-frequency words was diminished. A model for recognition judgment is proposed that assumes the use of a common criterion for low- and high-frequency words.     

Word frequency effects in immediate serial recall: item familiarity and item co-occurrence have the same effect

In immediate serial recall, high-frequency words are better recalled than low-frequency words. A prevalent interpretation of this effect suggests that, at the point of recall, degraded representations undergo a reconstruction process calling upon long-term knowledge of the to-be-remembered items. Recently, Stuart and Hulme (2000) following Deese (1960), suggested that high-frequency items are better recalled due to their better long-term associative links. Their results revealed that a familiarisation procedure involving repeated presentations of the to-be-remembered items in pairs abolished the usual frequency effect. In the experiment reported here, an alternative interpretation of this result is examined. Prior to the memory task, subjects received either no familiarisation, item familiarisation, or pair familiarisation. Both item and pair familiarisation improved the item recall of low-frequency items to the same extent, suggesting that increased familiarity can account for the co-occurrence effect.     

Modeling the effects of repetitions, similarity, and normative word frequency on old-new recognition and judgments of frequency

Judgments of frequency for targets (old items) and foils (similar; dissimilar) steadily increase as the number of times a target is studied increases, but discrimination of targets from similar foils does not steadily improve, a phenomenon termed registration without learning (D. L. Hintzman & T. Curran, 1995; D. L. Hintzman, T. Curran, & B. Oppy, 1992). The present experiment explores this phenomenon with words of differing normative word frequency. The retrieving-effectively-from-memory model (REM; R. M. Shifrrin & M. Steyvers, 1997, 1998) predicts that low-frequency words will be better recognized than high-frequency words because low-frequency words have more distinctive memory representations. A corollary of this assumption predicts that the typical recognition word-frequency effect will be disrupted when similar foils are tested. These predictions were confirmed, but to fit both the recognition and the judgment-of-frequency data, the authors used a "dual-process" extension of the REM model.     

Letters and words in word identification

Studies by Barron and Henderson (1977) and Johnson (1975) provide evidence that whole words may be the unit of identification in word perception, rather than single letters. Johnson found that words were matched faster than a letter to the first letter in a word. Barron and Henderson found faster matching times for words than for legal non-word items in a letter-matching task. These findings support the interpretation that words are identified before individual letters. If so, a word-frequency effect should be expected. Experiments 1 and 2 tested for word vs. first-letter-in-word differences, as well as for a word-frequency effect in simultaneous and delayed visual matching tasks. In the simultaneous task, first letters in words were matched faster than words. In the delayed task, there was no difference between matching words or matching the first letters in words. With both tasks there was a word-frequency effect for word matches but not for first-letter-in-word matches. In Experiment 3, first-letter matching time was unrelated to word frequency or lexical status, although it did vary with orthographic legality. These results, on the whole, are consistent with a race model in which identifications take place simultaneously at word, letter-cluster, and letter levels, rather than a sequential model in which the whole word is identified before the component letters.     

Episodic intertrial learning of younger and older adults: Effects of word frequency

ABSTRACT

Older adults have a demonstrable episodic memory deficit. The present study aimed to investigate whether the age deficit in episodic memory was influenced by stimulus characteristics known to produce differences in memory performance in younger adults, specifically word frequency. An intertrial paradigm was used whereby participants studied high- or low-frequency lists over several study-test trials, and the loss and gain of individual items was measured across trials; putative measures of consolidation and encoding. The results show that high-frequency words are recalled significantly better than low-frequency words. Older adults acquired high-frequency words at a greater rate across trials than they did for low-frequency words, an effect not evident in the younger adults. Older adults were found to have deficits in both encoding and consolidation as measured by losses and gains of items across trials. The results support the inter-item association theory of the word frequency effect on recall, with the age differences suggesting that memory deficits are sensitive to stimuli characteristics – one interpretation being that the ease of processing of the stimuli at encoding facilitates later recall.     

Sensory modality and the word-frequency effect

Two experiments were conducted to examine whether the word-frequency effect in recognition memory is primarily a modality-dependent phenomenon. In the first experiment, the presentation modality of a target word was varied orthogonally during the input of the test phases. In the second, the subjects were forced to process each input word at the letter-byo letter level, thus minimizing the orthographical differences between the high- and low-frequency words. The word-frequency effect was found in every experimental condition and should be considered a modality-independent phenomenon. A semantically based interpretation of this effect was proposed.     

Effects of pair collaboration and word-frequency in recognition memory: a study with the remember-know procedure

The present study investigated the effects of pair collaboration and word-frequency on recognition memory, using the "remember-know" procedure. The aim was to test the predictions of the information-exchange hypothesis (Clark, Hori, Putnam & Martin, 2000), which states that collaborative facilitation occurs when participants are able to share their recollective memories with other members of the group. Results showed that recognition performance was significantly better in the collaborative than in the individual condition, and better for low-frequency than for high-frequency words. The advantage of collaborating dyads was produced by an increase of correct hits, coupled with a significant reduction of false alarms. Furthermore, the analysis of the "remember" (R) and "know" (K) responses indicated that the effects of both pair collaboration and word-frequency were larger on recollection than on familiarity processes. It is concluded that, in a collaborative condition, arguments based on the retrieval of the contextual details associated with the target words are more effective than those based on familiarity in increasing the proportions of correct hits. In addition, it is proposed that collaboration may lead to a reduction of the probability to accept new items on the basis of familiarity (K) responses.     

A dissociative word-frequency X levels-of-processing interaction in episodic recognition and lexical decision tasks

The effects of levels-of-processing and word frequency were directly compared in three different memory tests. In the episodic recognition test, the subjects decided whether or not a word or a pronounceable nonword had been previously studied. In the two lexical decision tests with either pronounceable or unpronounceable nonwords as distractors, the subjects decided whether a test item was a word or a nonword. There were four main results: (1) in all three tests, reaction times (RTs) in response to studied words were faster if they had received semantic rather than rhyme processing during study; (2) in the episodic recognition test, RTs were faster for low- than for high-frequency words; in both lexical decision tests, RTs were faster for high- than for low-frequency words, though less so when the nonword distractors were unpronounceable; (3) prior study facilitated lexical decisions more in response to low- than to high-frequency words, thereby attenuating the word-frequency effect, but more so when the nonword distractors were pronounceable; (4) in the lexical decision test with pronounceable nonword distractors, relative to prior rhyme processing, prior semantic processing facilitated performance more for high- than for low-frequency words, whereas the opposite was the case in the episodic recognition test. Discussion focused on the relationship of these results to current views of the mechanisms by which (1) word frequency and depth of processing affect performance in implicit and explicit memory tests, and (2) repetition priming attenuates word-frequency effects for lexical decisions.     

An examination of word frequency and neighborhood density in the development of spoken-word recognition

In this study, the effects of word-frequency and phonological similarity relations in the development of spoken-word recognition were examined. Seven-, 9-, and 11-year-olds and adults listened to increasingly longer segments of high- and low-frequency monosyllabic words with many or few word neighbors that sounded similar (neighborhood density). Older children and adults required less of the acoustic-phonetic information to recognize words with few neighbors and low-frequency words than did younger children. Adults recognized high-frequency words with few neighbors on the basis of less input than did all three of the children’s groups. All subjects showed a higher proportion of different-word guesses for words with many versus few neighbors. A frequency × neighborhood density interaction revealed that recognition is facilitated for high-frequency words with few versus many neighbors; the opposite was found for low-frequency words. Results are placed within a developmental framework on the emergence of the phoneme as a unit in perceptual processing.     

A reexamination of stimulus-frequency effects in recognition: two mirrors for low- and high-frequency pseudowords

The word-frequency mirror effect (more hits and fewer false alarms for low-frequency than for high-frequency words) has intrigued memory researchers, and multiple accounts have been offered to explain the result. In this study, participants were differentially familiarized to various pseudowords in a familiarization phase that spanned multiple weeks. Recognition tests given during the first week of familiarization replicated a result of W. T. Maddox and W. K. Estes (1997) that failed to show the classic word-frequency mirror effect for pseudowords; however, recognition tests given toward the end of training showed the classic mirror pattern. In addition, a stimulus-frequency mirror effect for "remember" vs. "know" judgments was obtained. These data are consistent with an account of the mirror effect that posits the involvement of dual processes for episodic recognition.     

Discrimination learning as a function of differences in materials: A proposed explanation

The present study affords an explanation for the consistent, but not always statistically significant, pattern showing superior verbal discrimination learning performance for low- as compared to high-frequency words. In a frequency judgment task, it was found that relative to high-frequency words, low-frequency words for which Ss (sixth graders) knew the meanings produced apparent frequency measures consistent with superior verbal discrimination learning, while low-frequency words that were unknown to the children did not. These results, taken together with those based on comparisons of pictures and high-frequency words, lend themselves to a modified Weber’s law interpretation of stimulus material differences in discrimination learning.     

The low-frequency encoding disadvantage: Word frequency affects processing demands

Low-frequency words produce more hits and fewer false alarms than high-frequency words in a recognition task. The low-frequency hit rate advantage has sometimes been attributed to processes that operate during the recognition test (e.g., L. M. Reder et al., 2000). When tasks other than recognition, such as recall, cued recall, or associative recognition, are used, the effects seem to contradict a low-frequency advantage in memory. Four experiments are presented to support the claim that in addition to the advantage of low-frequency words at retrieval, there is a low-frequency disadvantage during encoding. That is, low-frequency words require more processing resources to be encoded episodically than high-frequency words. Under encoding conditions in which processing resources are limited, low-frequency words show a larger decrement in recognition than high-frequency words. Also, studying items (pictures and words of varying frequencies) along with low-frequency words reduces performance for those stimuli.     

The word frequency effect in lexical decision: Finding a frequency-based component

Subjects making lexical decisions are reliably faster in responding to high-frequency words than to low-frequency words. This is known as the word frequency effect. We wished to demonstrate that some portion of this effect was due to frequency differences between words rather than to other dimensions correlated with word frequency. Three groups of subjects (10 engineers, 10 nurses, and I0 law students) made lexical decisions about 720 items, half words and half nonwords, from six different categories (engineering, medical, low-frequency nontechnical, medium-frequency nontechnical, and two groups of high-frequency nontechnical). Results of two analyses of variance revealed a crossover interaction such that engineers were faster in responding to engineering words than to medical words, whereas nurses were faster in responding to medical words than to engineering words. The engineering and medical words were equally long and equally infrequent by standard word counts. We take this as support for a frequency-based component in the word frequency effect. The practical implications of this research for estimating the readability of technical text are discussed.     

Base word Frequency and Pseudohomophone Naming

The advantage of naming pseudohomophones over non-pseudohomophones has been interpreted as reflecting the contribution of whole-word lexical representations in phonological coding. A whole-word interpretation was further supported by Taft and Russell (1992), who reported a pseudohomophone frequency effect such that pseudohomophones were named faster if they corresponded to high- than to low-frequency base-words (e.g. poast vs. hoast ). Experiment 1 replicated this pseudohomophone frequency effect using the Taft and Russell items. Further analyses showed, however, that the pseudohomophones in Taft and Russell's high-frequency group were more orthographically similar to words than the pseudohomophones in the low-frequency group. These differences in orthography may have been the cause of the 'frequency' effects. In Experiment 2, a new set of high- and low-frequency pseudohomophones was constructed that were matched on orthographic factors (i.e. SPBF and N). With these items, a standard pseudohomophone advantage was found such that pseudohomophones were named faster and more accurately than non-pseudohomophones. However, in contrast to Taft and Russell's results, pseudohomophone naming was not related to base-word frequency. We conclude that the pseudohomophone advantage occurs at a postlexical stage in non-word naming.     

How lexical decision is affected by recent experience: Symmetric versus asymmetric frequency-blocking effects

In a lexical decision task (LDT) in which list composition is manipulated, a typical finding to date has been a slowdown for easy items (e.g., high-frequency words) but little speedup for hard items (e.g., low-frequency words) when they are mixed together. This asymmetric frequency-blocking effect contrasts with the symmetric pattern (both a speedup for hard items and a slowdown for easy items when they are mixed together) observed with the naming task. In the present study, we investigated the mechanism responsible for the asymmetric blocking effect in the LDT within a model of blocking effect proposed by Mozer, Kinoshita, and Davis (2003), termed the adaptation-to-the-statistics-of-the-environment (ASE) model. Experiments 1A and 1B showed that when the same high- and low-frequency words were used, consistent with the existing literature, an asymmetric blocking effect was found in the LDT and a symmetric blocking effect was found in the naming task. Within the ASE model, a symmetric versus asymmetric blocking effect can be explained in terms of different asymptotic rates in subjective estimates of error probability. Experiments 2 and 3 tested and confirmed a prediction of the model based on this assumption that a speedup of hard items would be observed in an LDT with hard items whose subjective error probability asymptotes near zero (low-frequency words with high familiarity ratings that subjects could be certain were words). Implications of the model for task differences in reaction times are discussed.     

The ERP signature of the contextual diversity effect in visual word recognition

Behavioral experiments have revealed that words appearing in many different contexts are responded to faster than words that appear in few contexts. Although this contextual diversity (CD) effect has been found to be stronger than the word-frequency (WF) effect, it is a matter of debate whether the facilitative effects of CD and WF reflect the same underlying mechanisms. The analysis of the electrophysiological correlates of CD may shed some light on this issue. This experiment is the first to examine the ERPs to high- and low-CD words when WF is controlled for. Results revealed that while high-CD words produced faster responses than low-CD words, their ERPs showed larger negativities (225–325 ms) than low-CD words. This result goes in the opposite direction of the ERP WF effect (high-frequency words elicit smaller N400 amplitudes than low-frequency words). The direction and scalp distribution of the CD effect resembled the ERP effects associated with “semantic richness.” Thus, while apparently related, CD and WF originate from different sources during the access of lexical-semantic representations.     

The effects of word co-occurrence on short-term memory: associative links in long-term memory affect short-term memory performance

In immediate serial recall tasks, high-frequency words are recalled better than low-frequency words. This has been attributed to high-frequency words' being better represented and providing more effective support to a redintegration process at retrieval (C. Hulme et al., 1997). In studies of free recall, there is evidence that frequency of word co-occurrence, rather than word frequency per se, may explain the recall advantage enjoyed by high-frequency words (J. Deese, 1960). The authors present evidence that preexposing pairs of low-frequency words, so as to create associative links between them, has substantial beneficial effects on immediate serial recall performance. These benefits, which are not attributable to simple familiarization with the words per se, do not occur for high-frequency words. These findings indicate that associative links between items in long-term memory have important effects on short-term memory performance and suggest that the effects of word frequency in short-term memory tasks are related to differences in interitem associations in long-term memory.     

A strict response criterion yields a mirror effect in the novelty paradigm

According to the novelty/encoding hypothesis (NEH; Tulving & Kroll, 1995), efficacy of encoding information into long-term memory depends on the movelty of the information. Recognition accuracy is higher for novel than for previously familiarized material. This novelty effect is not a mirror effect: the superiority of novel over familiar items is not found in the hit rates but only in the false-alarm rates. The main result in the present replication study was that novel hit rates were higher than familiar ones when the most confident responses were examined separately, and thus a mirror effect could be demonstrated for these data, for both the low- and the high-frequency words. Similarly, the word-frequency effect on hits was stronger when a stricter response criterion was applied. It was concluded that the novelty effect and the word-frequency effect are more similar to one another than has hitherto been thought.     

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.     

Context effects on remembering and knowing: the expectancy heuristic

Three experiments are reported examining the effect of context on remember-know judgments. In Experiments 1 and 2, medium-frequency words were intermixed with high-frequency or low-frequency words at study or at test, respectively. Remember responses were greater for medium-frequency targets when they were studied or tested among high-frequency, as compared with low-frequency, words. The authors proposed a decision-based mechanism called "the expectancy heuristic" to explain why remember responses were more likely when items were studied or tested in the context of words that were relatively less distinct. According to the expectancy heuristic, when items on a recognition test exceed an expected level of memorability they will be given a remember judgment but when they do not, but are still more familiar than new words, they will be given a know judgment. Experiment 3, which varied expectancies about the strength of tested targets, demonstrated the use of the expectancy heuristic, indicating that it operates by selectively influencing the remember criterion rather than by influencing recollection of studied items.