Word Recognition In Adults Research Articles

Neighbourhood Density in Spoken Word Recognition: An Eye-Tracking Study

Bilingual acquisition research has so far focused on comparisons with monolingual children in terms of linguistic features, performance on standardised tests, input, etc. In contrast, new methodologies, such as eye-tracking, can offer a more detailed understanding of the way bilinguals use both language systems. Eye fixations provide evidence of online processing. This study investigates spoken word recognition in children and adults. Word retrieval is affected by the number of words that minimally differ from the target (neighbourhood). Previous research found that only bilingual adults activated a similar-sounding competitor from the other language. As children have been found to be sensitive to neighbourhood density from quite early in previous research, similar results might be expected. This study includes 56 subjects (11 German–English bilingual and 12 English monolingual children, aged 8; 21 English monolingual and 12 German–English bilingual adults). The subjects’ online processing of competing items for high- and low-density targets was compared. The results confirm that neighbourhood density affects word recognition in adults and children. The bilingual children activated same-language competitors as well as similar-sounding competitors from the other language. Adults and children differed in terms of latencies, and the monolinguals were more accurate than the bilingual subjects.

Speech and Language Outcomes in Adults and Children with Cochlear Implants

Cochlear implants (CIs) represent a significant engineering and medical milestone in the treatment of hearing loss for both adults and children. In this review, we provide a brief overview of CI technology, describe the benefits that CIs can provide to adults and children who receive them, and discuss the specific limitations and issues faced by CI users. We emphasize the relevance of CIs to the linguistics community by demonstrating how CIs successfully provide access to spoken language. Furthermore, CI research can inform our basic understanding of spoken word recognition in adults and spoken language development in children. Linguistics research can also help us address the major clinical issue of outcome variability and motivate the development of new clinical tools to assess the unique challenges of adults and children with CIs, as well as novel interventions for individuals with poor outcomes.

Talker Adaptation and Lexical Difficulty Impact Word Recognition in Adults with Cochlear Implants

Introduction: Talker-specific adaptation facilitates speech recognition in normal-hearing listeners. This study examined talker adaptation in adult cochlear implant (CI) users. Three hypotheses were tested: (1) high-performing adult CI users show improved word recognition following exposure to a talker (“talker adaptation”), particularly for lexically hard words, (2) individual performance is determined by auditory sensitivity and neurocognitive skills, and (3) individual performance relates to real-world functioning. Methods: Fifteen high-performing, post-lingually deaf adult CI users completed a word recognition task consisting of 6 single-talker blocks (3 female/3 male native English speakers); words were lexically “easy” and “hard.” Recognition accuracy was assessed “early” and “late” (first vs. last 10 trials); adaptation was assessed as the difference between late and early accuracy. Participants also completed measures of spectral-temporal processing and neurocognitive skills, as well as real-world measures of multiple-talker sentence recognition and quality of life (QoL). Results: CI users showed limited talker adaptation overall, but performance improved for lexically hard words. Stronger spectral-temporal processing and neurocognitive skills were weakly to moderately associated with more accurate word recognition and greater talker adaptation for hard words. Finally, word recognition accuracy for hard words was moderately related to multiple-talker sentence recognition and QoL. Conclusion: Findings demonstrate a limited talker adaptation benefit for recognition of hard words in adult CI users. Both auditory sensitivity and neurocognitive skills contribute to performance, suggesting additional benefit from adaptation for individuals with stronger skills. Finally, processing differences related to talker adaptation and lexical difficulty may be relevant to real-world functioning.

Compensatory cross-modal effects of sentence context on visual word recognition in adults

Reading involves mapping combinations of a learned visual code (letters) onto meaning. Previous studies have shown that when visual word recognition is challenged by visual degradation, one way to mitigate these negative effects is to provide "top–down" contextual support through a written congruent sentence context. Crowding is a naturally occurring visual phenomenon that impairs object recognition and also affects the recognition of written stimuli during reading. Thus, access to a supporting semantic context via a written text is vulnerable to the detrimental impact of crowding on letters and words. Here, we suggest that an auditory sentence context may provide an alternative source of semantic information that is not influenced by crowding, thus providing “top–down” support cross-modally. The goal of the current study was to investigate whether adult readers can cross-modally compensate for crowding in visual word recognition using an auditory sentence context. The results show a significant cross-modal interaction between the congruency of the auditory sentence context and visual crowding, suggesting that interactions can occur across multiple levels of processing and across different modalities to support reading processes. These findings highlight the need for reading models to specify in greater detail how top–down, cross-modal and interactive mechanisms may allow readers to compensate for deficiencies at early stages of visual processing.

Vocabulary size and structure affects real-time lexical recognition in 18-month-olds.

The mature lexicon encodes semantic relations between words, and these connections can alternately facilitate and interfere with language processing. We explore the emergence of these processing dynamics in 18-month-olds (N = 79) using a novel approach that calculates individualized semantic structure at multiple granularities in participants’ productive vocabularies. Participants completed two interleaved eye-tracked word recognition tasks involving semantically unrelated and related picture contexts, which sought to measure the impact of lexical facilitation and interference on processing, respectively. Semantic structure and vocabulary size differentially impacted processing in each task. Category level structure facilitated word recognition in 18-month-olds with smaller productive vocabularies, while overall lexical connectivity interfered with word recognition for toddlers with relatively larger vocabularies. The results suggest that, while semantic structure at multiple granularities is measurable even in small lexicons, mechanisms of semantic interference and facilitation are driven by the development of structure at different granularities. We consider these findings in light of accounts of adult word recognition that posits that different levels of structure index strong and weak activation from nearby and distant semantic neighbors. We also consider further directions for developmental change in these patterns.

Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment.

Older adults are slower at recognizing visual objects than younger adults. The same is true for recognizing that a letter string is a real word. People with Alzheimer's disease (AD) or Mild Cognitive Impairment (MCI) demonstrate even longer responses in written word recognition than elderly controls. Despite the general tendency towards slower recognition in aging and neurocognitive disorders, certain characteristics of words influence word recognition speed regardless of age or neuropathology (e.g., a word's frequency of use). We present here a protocol for examining the influence of lexical characteristics on word recognition response times in a simple lexical decision experiment administered to younger and older adults and people with MCI or AD. In this experiment, participants are asked to decide as quickly and accurately as possible whether a given letter string is an actual word or not. We also describe mixed-effects models and principal components analysis that can be used to detect the influence of different types of lexical variables or individual characteristics of participants on word recognition speed.

Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment

Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment

Facilitatory Effects of Multi-Word Units in Lexical Processing and Word Learning: A Computational Investigation.

Previous studies have suggested that children and adults form cognitive representations of co-occurring word sequences. We propose (1) that the formation of such multi-word unit (MWU) representations precedes and facilitates the formation of single-word representations in children and thus benefits word learning, and (2) that MWU representations facilitate adult word recognition and thus benefit lexical processing. Using a modified version of an existing computational model (McCauley and Christiansen, 2014), we extract MWUs from a corpus of child-directed speech (CDS) and a corpus of conversations among adults. We then correlate the number of MWUs within which each word appears with (1) age of first production and (2) adult reaction times on a word recognition task. In doing so, we take care to control for the effect of word frequency, as frequent words will naturally tend to occur in many MWUs. We also compare results to a baseline model which randomly groups words into sequences—and find that MWUs have a unique facilitatory effect on both response variables, suggesting that they benefit word learning in children and word recognition in adults. The effect is strongest on age of first production, implying that MWUs are comparatively more important for word learning than for adult lexical processing. We discuss possible underlying mechanisms and formulate testable predictions.

Nurturing a lexical legacy: reading experience is critical for the development of word reading skill

The scientific study of reading has taught us much about the beginnings of reading in childhood, with clear evidence that the gateway to reading opens when children are able to decode, or ‘sound out’ written words. Similarly, there is a large evidence base charting the cognitive processes that characterise skilled word recognition in adults. Less understood is how children develop word reading expertise. Once basic reading skills are in place, what factors are critical for children to move from novice to expert? This paper outlines the role of reading experience in this transition. Encountering individual words in text provides opportunities for children to refine their knowledge about how spelling represents spoken language. Alongside this, however, reading experience provides much more than repeated exposure to individual words in isolation. According to the lexical legacy perspective, outlined in this paper, experiencing words in diverse and meaningful language environments is critical for the development of word reading skill. At its heart is the idea that reading provides exposure to words in many different contexts, episodes and experiences which, over time, sum to a rich and nuanced database about their lexical history within an individual’s experience. These rich and diverse encounters bring about local variation at the word level: a lexical legacy that is measurable during word reading behaviour, even in skilled adults.

Developmental differences in the influence of phonological similarity on spoken word processing in Mandarin Chinese

The developmental trajectory of spoken word recognition has been well established in Indo-European languages, but to date remains poorly characterized in Mandarin Chinese. In this study, typically developing children (N=17; mean age 10; 5) and adults (N=17; mean age 24) performed a picture–word matching task in Mandarin while we recorded ERPs. Mismatches diverged from expectations in different components of the Mandarin syllable; namely, word-initial phonemes, word-final phonemes, and tone. By comparing responses to different mismatch types, we uncovered evidence suggesting that both children and adults process words incrementally. However, we also observed key developmental differences in how subjects treated onset and rime mismatches. This was taken as evidence for a stronger influence of top-down processing on spoken word recognition in adults compared to children. This work therefore offers an important developmental component to theories of Mandarin spoken word recognition.

A Bruner-Potter effect in audition? Spoken word recognition in adult aging.

Bruner and Potter (1964) demonstrated the surprising finding that incrementally increasing the clarity of images until they were correctly recognized (ascending presentation) was less effective for recognition than presenting images in a single presentation at that same clarity level. This has been attributed to interference from incorrect perceptual hypotheses formed on the initial presentations under ascending conditions. We demonstrate an analogous effect for spoken word recognition in older adults, with the size of the effect predicted by working memory span. This effect did not appear for young adults, whose group spans exceeded that of the older adults.

How a hobby can shape cognition: visual word recognition in competitive Scrabble players

Competitive Scrabble is an activity that involves extraordinary word recognition experience. We investigated whether that experience is associated with exceptional behavior in the laboratory in a classic visual word recognition paradigm: the lexical decision task (LDT). We used a version of the LDT that involved horizontal and vertical presentation and a concreteness manipulation. In Experiment 1, we presented this task to a group of undergraduates, as these participants are the typical sample in word recognition studies. In Experiment 2, we compared the performance of a group of competitive Scrabble players with a group of age-matched nonexpert control participants. The results of a series of cognitive assessments showed that the Scrabble players and control participants differed only in Scrabble-specific skills (e.g., anagramming). Scrabble expertise was associated with two specific effects (as compared to controls): vertical fluency (relatively less difficulty judging lexicality for words presented in the vertical orientation) and semantic deemphasis (smaller concreteness effects for word responses). These results suggest that visual word recognition is shaped by experience, and that with experience there are efficiencies to be had even in the adult word recognition system.

Phonological priming and cohort effects in toddlers

Adult word recognition is influenced by prior exposure to phonologically or semantically related words ( cup primes cat or plate) compared to unrelated words ( door), suggesting that words are organised in the adult lexicon based on their phonological and semantic properties and that word recognition implicates not just the heard word, but also related words. We investigate the phonological organisation of the toddler lexicon with two experiments using a picture priming technique. Twenty-four month olds showed inhibition of target recognition in related primed trials compared to unrelated primed trials (Experiment 1) and also in related primed trials compared to unprimed trials (Experiment 2). Further analysis of children’s responding found that this inhibition effect was modulated by the cohort and neighbourhood size of the words tested. Overall, the results indicate a lexical basis for the reported effects and suggest that the phonological properties provide an organisational basis for words in the toddler lexicon.

Adaptation to novel accents by toddlers.

Word recognition is a balancing act: listeners must be sensitive to phonetic detail to avoid confusing similar words, yet, at the same time, be flexible enough to adapt to phonetically variable pronunciations, such as those produced by speakers of different dialects or by non-native speakers. Recent work has demonstrated that young toddlers are sensitive to phonetic detail during word recognition; pronunciations that deviate from the typical phonological form lead to a disruption of processing. However, it is not known whether young word learners show the flexibility that is characteristic of adult word recognition. The present study explores whether toddlers can adapt to artificial accents in which there is a vowel category shift with respect to the native language. 18-20-month-olds heard mispronunciations of familiar words (e.g., vowels were shifted from [a] to [æ]: "dog" pronounced as "dag"). In test, toddlers were tolerant of mispronunciations if they had recently been exposed to the same vowel shift, but not if they had been exposed to standard pronunciations or other vowel shifts. The effects extended beyond particular items heard in exposure to words sharing the same vowels. These results indicate that, like adults, toddlers show flexibility in their interpretation of phonological detail. Moreover, they suggest that effects of top-down knowledge on the reinterpretation of phonological detail generalize across the phono-lexical system.

Adult word recognition and visual sequential memory

Two experiments were conducted investigating the role of visual sequential memory skill in the word recognition efficiency of undergraduate university students. Word recognition was assessed in a lexical decision task using regularly and strangely spelt words, and nonwords that were either standard orthographically legal strings or items made from words with internal transposed letters. Symbol memory was evaluated in a recognition procedure in which sequences of three to five unfamiliar complex symbols were presented, each followed by a subsequent array containing the symbols either in the same order or with an order transposition. In Experiment 1, there was no independent contribution of symbol memory to either word or nonword processing independently of the ability to discriminate the symbols from one another. In Experiment 2, although symbol memory made a significant contribution to word recognition independently of symbol discrimination and letter identification for two conditions—long strangely spelt words and short transposed-letter items, the effects were extremely small. It was concluded that non-verbal visual sequential memory skill does not play a central role in underpinning efficiency of word recognition in experienced adult readers.

Relations among linguistic and cognitive skills and spoken word recognition in adults with cochlear implants.

This study examined spoken word recognition in adults with cochlear implants (CIs) to determine the extent to which linguistic and cognitive abilities predict variability in speech-perception performance. Both a traditional consonant-vowel-consonant (CVC)-repetition measure and a gated-word recognition measure (F. Grosjean, 1996) were used. Stimuli in the gated-word-recognition task varied in neighborhood density. Adults with CIs repeated CVC words less accurately than did age-matched adults with normal hearing sensitivity (NH). In addition, adults with CIs required more acoustic information to recognize gated words than did adults with NH. Neighborhood density had a smaller influence on gated-word recognition by adults with CIs than on recognition by adults with NH. With the exception of 1 outlying participant, standardized, norm-referenced measures of cognitive and linguistic abilities were not correlated with word-recognition measures. Taken together, these results do not support the hypothesis that cognitive and linguistic abilities predict variability in speech-perception performance in a heterogeneous group of adults with CIs. Findings are discussed in light of the potential role of auditory perception in mediating relations among cognitive and linguistic skill and spoken word recognition.

Relationships among vocabulary size, nonverbal cognition, and spoken word recognition in adults with cochlear implants

Recent research has attempted to identify the factors that predict speech perception performance among users of cochlear implants (CIs). Studies have found that approximately 20%–60% of the variance in speech perception scores can be accounted for by factors including duration of deafness, etiology, type of device, and length of implant use, leaving approximately 50% of the variance unaccounted for. The current study examines the extent to which vocabulary size and nonverbal cognitive ability predict CI listeners’ spoken word recognition. Fifteen postlingually deafened adults with nucleus or clarion CIs were given standardized assessments of nonverbal cognitive ability and expressive vocabulary size: the Expressive Vocabulary Test, the Test of Nonverbal Intelligence-III, and the Woodcock-Johnson-III Test of Cognitive Ability, Verbal Comprehension subtest. Two spoken word recognition tasks were administered. In the first, listeners identified isophonemic CVC words. In the second, listeners identified gated words varying in lexical frequency and neighborhood density. Analyses will examine the influence of lexical frequency and neighborhood density on the uniqueness point in the gating task, as well as relationships among nonverbal cognitive ability, vocabulary size, and the two spoken word recognition measures. [Work supported by NIH Grant P01 DC00110 and by the Lions 3M Hearing Foundation.]

Some implications from language development for merge

Recent investigations indicate that, around 7-months-of-age, infants begin to show some ability to recognize words in fluent speech. In segmenting and recognizing words, infants rely on information available in the speech signal. We consider what implications these findings have for adult word recognition models in general, and for Merge, in particular.

Neighbourhood Effects on Masked Form Priming in Developing Readers

The processing of a written word can be facilitated by the brief prior presentation of an orthographically similar stimulus. However, for adults, this masked form-priming effect does not occur if the target looks like many other words (i.e. if it has many neighbours). The usual interpretation of this result is that the adult word recognition system is tuned to the differing discrimination demands of words: If a word looks like many others, a more precise recognition procedure is required than if it is orthographically distinctive. This theory has developmental implications: Children should show more form priming for high neighbourhood words than adults and should show a gradual reduction in priming as their written vocabularies become larger. Masked form priming was examined in three groups of developing readers, from grades 2, 4 and 6, and a group of adults. In a lexical decision task, the children showed significantly greater priming overall than the adults for high N words. However, the predicted gradual attenuation across age was not found. Supplementary analyses suggested that the adaptation to lexical density may not occur until a somewhat more advanced stage of reading than we had first expected.

Orthographic onsets as functional units of adult word recognition

Five experiments are described. Experiments 1 to 3 used a case-change methodology to test the hypothesis that orthographic onsets serve as units of visual word recognition. It was assumed that presenting words in mixed case would disrupt processing more strongly when the case change occurred within a subunit of word recognition than when the case change occurred between subunits of word recognition. The orthographic onset hypothesis was supported in two of three experiments. The sensitivity of the case-change methodology as a means of testing the orthographic onset hypothesis was examined in two further experiments using case change to disrupt orthographic rimes. Again, mixed results were observed. Given the abundance of evidence that, for skilled readers, ortho-graphic rimes serve as functional units of print and independent arguments that the case-change methodology represents an inherently conservative test of hypotheses concerning multiletter units of print, the current results provide preliminary evidence for the ortho-graphic onset as a functional unit of print.