Orthographic neighbors and visual word recognition

Two lexical decision experiments, using words that were selected and closely matched on several criteria associated with lexical access, provide evidence of facilitatory effects of orthographic neighborhood size and no significant evidence of inhibitory effects of orthographic neighborhood frequency on lexical access. The words used in Experiment 1 had few neighbors that were higher in frequency. In Experiment 2, the words employed had several neighbors that were higher in frequency. Both experiments showed that words possessing few neighbors evoked slower responses than those possessing many neighbors. Also, in both experiments, neighborhood size effects occurred even though words from large neighborhoods had more potentially interfering higher-frequency neighbors than words from small neighborhoods.     

Children like dense neighborhoods: Orthographic neighborhood density effects in novel readers

Previous evidence with English beginning readers suggests that some orthographic effects, such as the orthographic neighborhood density effects, could be stronger for children than for adults. Particularly, children respond more accurately to words with many orthographic neighbors than to words with few neighbors. The magnitude of the effects for children is much higher than for adults, and some researchers have proposed that these effects could be progressively modulated according to reading expertise. The present paper explores in depth how children from 1st to 6th grade perform a lexical decision with words that are from dense or sparse orthographic neighborhoods, attending not only to accuracy measures, but also to response latencies, through a computer-controlled task. Our results reveal that children (like adults) show clear neighborhood density effects, and that these effects do not seem to depend on reading expertise. Contrarily to previous claims, the present work shows that orthographic neighborhood effects are not progressively modulated by reading skill. Further, these data strongly support the idea of a general language-independent preference for using the lexical route instead of grapheme-to-phoneme conversions, even in beginning readers. The implications of these results for developmental models in reading and for models in visual word recognition and orthographic encoding are discussed.     

Orthographic neighborhood and concreteness effects in the lexical decision task

The experiment reported here investigated the sensitivity of concreteness effects to orthographic neighborhood density and frequency in the visual lexical decision task. The concreteness effect was replicated with a sample of concrete and abstract words that were not matched for orthographic neighborhood features and in which concrete words turned out to have a higher neighborhood density than abstract words. No consistent effect of concreteness was found with a sample of concrete and abstract words matched for orthographic neighborhood density and frequency and having fewer neighbors and higher-frequency neighbors than the words of the first sample. Post hoc analyses of the results showed that orthographic neighborhood density was not a nuisance variable producing a spurious effect of concreteness but, instead, that the existence of higher-frequency neighbors constitutes a necessary condition for concreteness effects to appear in the lexical decision task. This finding is consistent with the hypothesis that semantic information is accessed and used to generate the responses in lexical decision when inhibition from orthographic forms delays the target word recognition.     

Repetition and form priming interact with neighborhood density at a brief stimulus onset asynchrony

The relationships between repetition- and form-priming effects and neighborhood density were analyzed in two masked priming experiments with the lexical decision task. Given that form-priming effects appear to be influenced by a word’s orthographic neighborhood, it is theoretically important to find out whether repetition priming also differs as a function of the word’s orthographic neighborhood. Within an activation framework, repetition- and form-priming effects are just quantitatively different phenomena, whereas the two effects are qualitatively different in a serial-ordered model of lexical access (theentry-opening model). The results show that repetition- and form-priming effects were stronger forhermit words than for words with many neighbors. These results pose some problems for both activation and serial-ordered models. The implications of these results for determining how neighbors affect the identification of a word are discussed.     

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.     

Spoken Language Activation Alters Subsequent Sign Language Activation in L2 Learners of American Sign Language

A large body of literature has characterized unimodal monolingual and bilingual lexicons and how neighborhood density affects lexical access; however there have been relatively fewer studies that generalize these findings to bimodal (M2) second language (L2) learners of sign languages. The goal of the current study was to investigate parallel language activation in M2L2 learners of sign language and to characterize the influence of spoken language and sign language neighborhood density on the activation of ASL signs. A priming paradigm was used in which the neighbors of the sign target were activated with a spoken English word and compared the activation of the targets in sparse and dense neighborhoods. Neighborhood density effects in auditory primed lexical decision task were then compared to previous reports of native deaf signers who were only processing sign language. Results indicated reversed neighborhood density effects in M2L2 learners relative to those in deaf signers such that there were inhibitory effects of handshape density and facilitatory effects of location density. Additionally, increased inhibition for signs in dense handshape neighborhoods was greater for high proficiency L2 learners. These findings support recent models of the hearing bimodal bilingual lexicon, which posit lateral links between spoken language and sign language lexical representations.     

The effects of "neighborhood size" in reading and lexical decision.

The effects of neighborhood size ("N")--the number of words differing from a target word by exactly 1 letter (i.e., "neighbors")--on word identification was assessed in 3 experiments. In Experiments 1 and 2, the frequency of the highest frequency neighbor was equated, and N had opposite effects in lexical decision and reading. In Experiment 1, a larger N facilitated lexical decision judgments, whereas in Experiment 2, a larger N had an inhibitory effect on reading sentences that contained the words of Experiment 1. Moreover, a significant inhibitory effect in Experiment 2 that was due to a larger N appeared on gaze duration on the target word, and there was no hint of facilitation on the measures of reading that tap the earliest processing of a word. In Experiment 3, the number of higher frequency neighbors was equated for the high-N and low-N words, and a larger N caused target words to be skipped significantly more and produced inhibitory effects later in reading, some of which were plausibly due to misidentification of the target word when skipped. Regression analyses indicated that, in reading, increasing the number of higher frequency neighbors had a clear inhibitory effect on word identification and that increasing the number of lower frequency neighbors may have a weak facilitative effect on word identification.     

Observing neighborhood effects without neighbors

With a new metric called phonological Levenshtein distance (PLD20), the present study explores the effects of phonological similarity and word frequency on spoken word recognition, using polysyllabic words that have neither phonological nor orthographic neighbors, as defined by neighborhood density (the N-metric). Inhibitory effects of PLD20 were observed for these lexical hermits: Close-PLD20 words were recognized more slowly than distant PLD20 words, indicating lexical competition. Importantly, these inhibitory effects were found only for low- (not high-) frequency words, in line with previous findings that phonetically related primes inhibit recognition of low-frequency words. These results indicate that the properties of PLD20--a continuous measure of word-form similarity--make it a promising new metric for quantifying phonological distinctiveness in spoken word recognition research.     

Semantic priming is affected by real-time phonological competition: Evidence for continuous cascading systems

Lexical-semantic access is affected by the phonological structure of the lexicon. What is less clear is whether such effects are the result of continuous activation between lexical form and semantic processing or whether they arise from a more modular system in which the timing of accessing lexical form determines the timing of semantic activation. This study examined this issue using the visual world paradigm by investigating the time course of semantic priming as a function of the number of phonological competitors. Critical trials consisted of high or low density auditory targets (e.g., horse) and a visual display containing a target, a semantically related object (e.g., saddle), and two phonologically and semantically unrelated objects (e.g., chimney, bikini). Results showed greater magnitude of priming for semantically related objects of low than of high density words, and no differences for high and low density word targets in the time course of looks to the word semantically related to the target. This pattern of results is consistent with models of cascading activation, which predict that lexical activation has continuous effects on the level of semantic activation, with no delays in the onset of semantic activation for phonologically competing words.     

Phonological similarity neighborhoods and children’s short-term memory: Typical development and dyslexia

In this article, we explore whether structural characteristics of the phonological lexicon affect serial recall in typically developing and dyslexic children. Recent work has emphasized the importance of long-term phonological representations in supporting short-term memory performance. This occurs via redintegration (reconstruction) processes, which show significant neighborhood density effects in adults. We assessed whether serial recall in children was affected by neighborhood density in word and nonword tasks. Furthermore, we compared dyslexic children with typically developing children of the same age or reading level. Dyslexic children are held to have impaired phonological representations of lexical items. These impaired representations may impair or prevent the use of long-term phonological representations to redintegrate short-term memory traces. We report significant rime neighborhood density effects for serial recall of both words and nonwords, for both dyslexic and typically developing children.     

Learning and consolidation of new spoken words in autism spectrum disorder

Autism spectrum disorder (ASD) is characterized by rich heterogeneity in vocabulary knowledge and word knowledge that is not well accounted for by current cognitive theories. This study examines whether individual differences in vocabulary knowledge in ASD might be partly explained by a difficulty with consolidating newly learned spoken words and/or integrating them with existing knowledge. Nineteen boys with ASD and 19 typically developing (TD) boys matched on age and vocabulary knowledge showed similar improvements in recognition and recall of novel words (e.g. ‘biscal’) 24 hours after training, suggesting an intact ability to consolidate explicit knowledge of new spoken word forms. TD children showed competition effects for existing neighbors (e.g. ‘biscuit’) after 24 hours, suggesting that the new words had been integrated with existing knowledge over time. In contrast, children with ASD showed immediate competition effects that were not significant after 24 hours, suggesting a qualitative difference in the time course of lexical integration. These results are considered from the perspective of the dual‐memory systems framework.     

Similarity relations among spoken words: The special status of rimes in English

This paper presents an analysis of the distribution of phonological similarity relations among monosyllabic spoken words in English. It differs from classical analyses of phonological neighborhood density (e.g., Luce &; Pisoni, 1998) by assuming that not all phonological neighbors are equal. Rather, it is assumed that the phonological lexicon has psycholinguistic structure. Accordingly, in addition to considering thenumber of phonological neighbors for any given word, it becomes important to consider thenature of these neighbors. If one type of neighbor is more dominant, neighborhood density effects may reflect levels of segmental representation other than the phoneme, particularly prior to literacy. Statistical analyses of the nature of phonological neighborhoods in terms ofrime neighbors (e.g.,hat/cat),consonant neighbors (e.g.,hat/hit), andlead neighbors (e.g.,hat/ham) were thus performed for all monosyllabic words in the Celex corpus (4,086 words). Our results show that most phonological neighbors are rime neighbors (e.g.,hat/cat) in English. Similar patterns were found when a corpus of words for which age-of-acquisition ratings were available was analyzed. The resultant database can be used as a tool for controlling and selecting stimuli when the role of lexical neighborhoods in phonological development and speech processing is examined.     

Effects of lexical competition on immediate memory span for spoken words

Current theories and models of the structural organization of verbal short-term memory are primarily based on evidence obtained from manipulations of features inherent in the short-term traces of the presented stimuli, such as phonological similarity. In the present study, we investigated whether properties of the stimuli that are not inherent in the short-term traces of spoken words would affect performance in an immediate memory span task. We studied the lexical neighbourhood properties of the stimulus items, which are based on the structure and organization of words in the mental lexicon. The experiments manipulated lexical competition by varying the phonological neighbourhood structure (i.e., neighbourhood density and neighbourhood frequency) of the words on a test list while controlling for word frequency and intra-set phonological similarity (family size). Immediate memory span for spoken words was measured under repeated and nonrepeated sampling procedures. The results demonstrated that lexical competition only emerged when a nonrepeated sampling procedure was used and the participants had to access new words from their lexicons. These findings were not dependent on individual differences in short-term memory capacity. Additional results showed that the lexical competition effects did not interact with proactive interference. Analyses of error patterns indicated that item-type errors, but not positional errors, were influenced by the lexical attributes of the stimulus items. These results complement and extend previous findings that have argued for separate contributions of long-term knowledge and short-term memory rehearsal processes in immediate verbal serial recall tasks.     

The effect of phonological neighborhood density on eye movements during reading

Recent research has indicated that phonological neighbors speed processing in a variety of isolated word recognition tasks. Nevertheless, as these tasks do not represent how we normally read, it is not clear if phonological neighborhood has an effect on the reading of sentences for meaning. In the research reported here, we evaluated whether phonological neighborhood density influences reading of target words embedded in sentences. The eye movement data clearly revealed that phonological neighborhood facilitated reading. This was evidenced by shorter fixations for words with large neighborhoods relative to words with small neighborhoods. These results are important in indicating that phonology is a crucial component of reading and that it affects early lexical processing.     

They call it like they see it: spontaneous naming and attention to shape

Two experiments explore children's spontaneous labeling of novel objects as a method to study early lexical access. The experiments also provide new evidence on children's attention to object shape when labeling objects. In Experiment 1, the spontaneous productions of 21 23- to 28-month-olds (mean 26;28) shown a set of novel, unnamed objects were analyzed both in terms of the specific words said and, via adult judgments, their likely perceptual basis. We found that children's spontaneous names were cued by the perceptual feature of shape. Experiment 2 examines the relation between spontaneous productions, name generalizations in a structured task, and vocabulary development in a group of children between 17 and 24 months of age (mean 21;6). Results indicate that object shape plays an important role in both spontaneous productions and novel noun generalization, but contrary to current hypotheses, children may name objects by shape from the earliest points of productive vocabulary development and this tendency may not be lexically specific.     

Orthographic neighborhood effects in perceptual identification and semantic categorization tasks: a test of the multiple read-out model

How should a word's orthographic neighborhood affect perceptual identification and semantic categorization, both of which require a word to be uniquely identified? According to the multiple read-out model (Grainger & Jacobs, 1996), inhibitory neighborhood frequency effects should be observed in these types of tasks, and facilitatory neighborhood size effects should not be. In Experiments 1 and 2 (perceptual identification), these effects were examined as a function of stimulus visibility (i.e., high vs. low visibility) to provide as full a test as possible of the model's predictions. In the high-visibility conditions, words with large neighborhoods were reported less accurately than words with small neighborhoods, but there was no effect of neighborhood frequency (i.e., whether the word had a higher frequency neighbor). In the low-visibility conditions, low-frequency words with large neighborhoods and low-frequency words with higher frequency neighbors showed superior identification performance. In the semantic categorization task (Experiment 3), words with large neighborhoods were responded to more rapidly than words with small neighborhoods, but there was no effect of neighborhood frequency. These results are inconsistent with two of the basic premises of the multiple read-out model--namely, that facilitatory neighborhood size effects are due to a variable response criterion (the sigma criterion), rather than to lexical selection processes, and that the lexical selection processes themselves produce an inhibitory neighborhood frequency effect (via the M criterion). Instead, the present results, in conjunction with previous findings, suggest that large neighborhoods (and perhaps higher frequency neighbors) do aid lexical selection.     

Is there a neighborhood frequency effect in English? Evidence from reading and lexical decision

What is the effect of a word's higher frequency neighbors on its identification time? According to activation-based models of word identification (J. Grainger & A. M. Jacobs, 1996; J. L. McClelland & D. E. Rumelhart, 1981), words with higher frequency neighbors will be processed more slowly than words without higher frequency neighbors because of the lexical competition mechanism embodied in these models. Although a critical prediction of these models, this inhibitory neighborhood frequency effect has been elusive in studies that have used English stimuli. In the present experiments, the effect of higher frequency neighbors was examined in the lexical decision task and when participants were reading sentences while their eye movements were monitored. Results suggest that higher frequency neighbors have little, if any, effect on the identification of English words. The implications for activation-based models of word identification are discussed.     

Learning new vocabulary during childhood: Effects of semantic training on lexical consolidation and integration

Research suggests that word learning is an extended process, with offline consolidation crucial for the strengthening of new lexical representations and their integration with existing lexical knowledge (as measured by engagement in lexical competition). This supports a dual memory systems account, in which new information is initially sparsely encoded separately from existing knowledge and integrated with long-term memory over time. However, previous studies of this type exploited unnatural learning contexts, involving fictitious words in the absence of word meaning. In this study, 5- to 9-year-old children learned real science words (e.g., hippocampus) with or without semantic information. Children in both groups were slower to detect pauses in familiar competitor words (e.g., hippopotamus) relative to control words 24 h after training but not immediately, confirming that offline consolidation is required before new words are integrated with the lexicon and engage in lexical competition. Children recalled more new words 24 h after training than immediately (with similar improvements shown for the recall and recognition of new word meanings); however, children who were exposed to the meanings during training showed further improvements in recall after 1 week and outperformed children who were not exposed to meanings. These findings support the dual memory systems account of vocabulary acquisition and suggest that the association of a new phonological form with semantic information is critical for the development of stable lexical representations.     

Distributional analyses in auditory lexical decision: Neighborhood density and word-frequency effects

In the present article, the effects of phonological neighborhood density and word frequency in spoken word recognition were examined using distributional analyses of response latencies in auditory lexical decision. A density × frequency interaction was observed in mean latencies; frequency effects were larger for low-density words than for high-density words. Distributional analyses further revealed that for low-density words, frequency effects were reflected in both distributional shifting and skewing, whereas for high-density words, frequency effects were purely mediated by distributional skewing. The results suggest that word frequency plays a role in early auditory word recognition only when there is relatively little competition between similar-sounding words, and that frequency effects in high-density words reflect postlexical checking.