Vowel bias in Danish word‐learning: processing biases are language‐specific

The present study explored whether the phonological bias favoring consonants found in French‐learning infants and children when learning new words (Havy & Nazzi, 2009; Nazzi, 2005) is language‐general, as proposed by Nespor, Peña and Mehler (2003), or varies across languages, perhaps as a function of the phonological or lexical properties of the language in acquisition. To do so, we used the interactive word‐learning task set up by Havy and Nazzi (2009), teaching Danish‐learning 20‐month‐olds pairs of phonetically similar words that contrasted either on one of their consonants or one of their vowels, by either one or two phonological features. Danish was chosen because it has more vowels than consonants, and is characterized by extensive consonant lenition. Both phenomena could disfavor a consonant bias. Evidence of word‐learning was found only for vocalic information, irrespective of whether one or two phonological features were changed. The implication of these findings is that the phonological biases found in early lexical processing are not language‐general but develop during language acquisition, depending on the phonological or lexical properties of the native language.     

Word learning and phonetic processing in preschool-age children

Consonants and vowels have been shown to play different relative roles in different processes, including retrieving known words from pseudowords during adulthood or simultaneously learning two phonetically similar pseudowords during infancy or toddlerhood. The current study explores the extent to which French-speaking 3- to 5-year-olds exhibit a so-called “consonant bias” in a task simulating word acquisition, that is, when learning new words for unfamiliar objects. In Experiment 1, the to-be-learned words differed both by a consonant and a vowel (e.g., /byf/-/duf/), and children needed to choose which of the two objects to associate with a third one whose name differed from both objects by either a consonant or a vowel (e.g., /dyf/). In such a conflict condition, children needed to favor (or neglect) either consonant information or vowel information. The results show that only 3-year-olds preferentially chose the consonant identity, thereby neglecting the vowel change. The older children (and adults) did not exhibit any response bias. In Experiment 2, children needed to pick up one of two objects whose names differed on either consonant information or vowel information. Whereas 3-year-olds performed better with pairs of pseudowords contrasting on consonants, the pattern of asymmetry was reversed in 4-year-olds, and 5-year-olds did not exhibit any significant response bias. Interestingly, girls showed overall better performance and exhibited earlier changes in performance than boys. The changes in consonant/vowel asymmetry in preschoolers are discussed in relation with developments in linguistic (lexical and morphosyntactic) and cognitive processing.     

Call me Alix,not Elix: vowels are more important than consonants in own‐name recognition at 5 months

Consonants and vowels differ acoustically and articulatorily, but also functionally: Consonants are more relevant for lexical processing, and vowels for prosodic/syntactic processing. These functional biases could be powerful bootstrapping mechanisms for learning language, but their developmental origin remains unclear. The relative importance of consonants and vowels at the onset of lexical acquisition was assessed in French‐learning 5‐month‐olds by testing sensitivity to minimal phonetic changes in their own name. Infants’ reactions to mispronunciations revealed sensitivity to vowel but not consonant changes. Vowels were also more salient (on duration and intensity) but less distinct (on spectrally based measures) than consonants. Lastly, vowel (but not consonant) mispronunciation detection was modulated by acoustic factors, in particular spectrally based distance. These results establish that consonant changes do not affect lexical recognition at 5 months, while vowel changes do; the consonant bias observed later in development does not emerge until after 5 months through additional language exposure.     

Constraints of vowels and consonants on lexical selection: Cross-linguistic comparisons

Languages differ in the constitution of their phonemic repertoire and in the relative distinctiveness of phonemes within the repertoire. In the present study, we asked whether such differences constrain spoken-word recognition, via two word reconstruction experiments, in which listeners turned non-words into real words by changing single sounds. The experiments were carried out in Dutch (which has a relatively balanced vowel-consonant ratio and many similar vowels) and in Spanish (which has many more consonants than vowels and high distinctiveness among the vowels). Both Dutch and Spanish listeners responded significantly faster and more accurately when required to change vowels as opposed to consonants; when allowed to change any phoneme, they more often altered vowels than consonants. Vowel information thus appears to constrain lexical selection less tightly (allow more potential candidates) than does consonant information, independent of language-specific phoneme repertoire and of relative distinctiveness of vowels.     

The mental representation of lexical form: a phonological approach to the recognition lexicon

We propose a psycholinguistic model of lexical processing which incorporates both process and representation. The view of lexical access and selection that we advocate claims that these processes are conducted with respect to abstract underspecified phonological representations of lexical form. The abstract form of a given item in the recognition lexicon is an integrated segmental-featural representation, where all predictable and non-distinctive information is withheld. This means that listeners do not have available to them, as they process the speech input, a representation of the surface phonetic realisation of a given word-form. What determines performance is the abstract, underspecified representation with respect to which this surface string is being interpreted. These claims were tested by studying the interpretation of the same phonological feature, vowel nasality, in two languages, English and Bengali. The underlying status of this feature differs in the two languages; nasality is distinctive only in consonants in English, while both vowels and consonants contrast in nasality in Bengali. Both languages have an assimilation process which spreads nasality from a nasal consonant to the preceding vowel. A cross-linguistic gating study was conducted to investigate whether listeners would interpret nasal and oral vowels differently in two languages. The results show that surface phonetic nasality in the vowel in VN sequences is used by English listeners to anticipate the upcoming nasal consonant. In Bengali, however, nasality is initially interpreted as an underlying nasal vowel. Bengali listeners respond to CVN stimuli with words containing a nasal vowel, until they get information about the nasal consonant. In contrast, oral vowels in both languages are unspecified for nasality and are interpreted accordingly. Listeners in both languages respond with CVN words (which have phonetic nasality on the surface) as well as with CVC words while hearing an oral vowel. The results of this cross-linguistic study support, in detail, the hypothesis that the listener's interpretation of the speech input is in terms of an abstract underspecified representation of lexical form.     

Developmental differences in short-lived auditory memory for various classes of speech sounds

Spoken serial recall by second-grade children of aurally presented lists of digits, synthetic stop consonants, and synthetic vowels showed a significant suffix effect (selective debilitation of recall at the final position under the stimulus suffix condition) only for the lists of digits and not for either consonants or vowels. Making the synthetic syllables more distinctive by simultaneously covarying the consonant and vowel failed to produce a suffix effect under a strict scoring criterion which required both consonant and vowel to be recalled correctly; however, when subjects were given credit for partially correct answers the suffix effect emerged. Adults given the redundant consonant-vowel syllables showed a significant suffix effect with the strict scoring criterion. However, when consonants and vowels varied orthogonally, the adults' performance showed the suffix effect only under the lenient scoring criterion. An argument is made for equivalence of basic memorial processing between children and adults, the difference being in the number of features needed to disambiguate the target items and in the ability to integrate these features to exploit interstimulus redundancy.     

Misreadings by beginning readers of Serbo-Croatian

Errors in reading aloud by the beginning reader have been interpreted as reflecting the difficulty and the importance of phonemic segmentation for the acquisition of reading skills. Results from previous studies on English words patterned as consonant-vowel-consonant showed: (1) more errors on vowels than on consonants; (2) more errors on word final consonants than on word initial consonants; and suggested that (3) consonant errors were based on phonetic confusions while vowel errors were not. In contrast to their English counterparts, the beginning readers of Serbo-Croatian tested in the present study committed proportionally fewer errors on their reading of vowels than of consonants but in common with their English counterparts, their reading of final consonants was more vulnerable to error than their reading of initial consonants. This pattern of errors was found for both word and pseudoword consonant-vowel-consonant structures and the pattern of vowel confusion, like the pattern of consonant confusions, was rationalized by speech-related factors. The differences between the patterns of confusions for Serbo-Croatian and for English could be due to the difference between the two orthographies in the precision with which they represent the phonology or to the fact that the vowels of English are qualitatively less distinct phonologically than the vowels of Serbo-Croatian.     

Finding words and rules in a speech stream: functional differences between vowels and consonants

We have proposed that consonants give cues primarily about the lexicon, whereas vowels carry cues about syntax. In a study supporting this hypothesis, we showed that when segmenting words from an artificial continuous stream, participants compute statistical relations over consonants, but not over vowels. In the study reported here, we tested the symmetrical hypothesis that when participants listen to words in a speech stream, they tend to exploit relations among vowels to extract generalizations, but tend to disregard the same relations among consonants. In our streams, participants could segment words on the basis of transitional probabilities in one tier and could extract a structural regularity in the other tier. Participants used consonants to extract words, but vowels to extract a structural generalization. They were unable to extract the same generalization using consonants, even when word segmentation was facilitated and the generalization made simpler. Our results suggest that different signal-driven computations prime lexical and grammatical processing.     

The relative position priming effect depends on whether letters are vowels or consonants

The relative position priming effect is a type of subset priming in which target word recognition is facilitated as a consequence of priming the word with some of its letters, maintaining their relative position (e.g., csn as a prime for casino). Five experiments were conducted to test whether vowel-only and consonant-only subset primes contribute equally to this effect. Experiment 1 revealed that this subset priming effect emerged when primes were composed exclusively of consonants, compared with vowel-only primes (csn-casino vs. aia-animal). Experiment 2 tested the impact of letter frequency in this asymmetry. Subset priming effects were obtained for both high- and low-frequency consonants but not for vowels, which rules out a letter frequency explanation. Experiment 3 tested the role of phonology and its contribution to the priming effects observed, by decreasing the prime duration. The results showed virtually the same effects as in the previous experiments. Finally, Experiments 4 and 5 explored the influence of repeated letters in the primes on the magnitude of the priming effects obtained for consonant and vowel subset primes (iuo-dibujo and aea-madera vs. mgn-imagen and rtr-frutero). Again, the results confirmed the priming asymmetry. We propose that a functional distinction between consonants and vowels, mainly based on the lexical constraints imposed by each of these types of letters, might provide an explanation for the whole set of results.     

The structure of graphemic representations

The analysis of the spelling performance of a brain-damaged dysgraphic subject is reported. The subject's spelling performance was affected by various graphotactic factors, such as the distinction between consonant and vowel and graphosyllabic structure. For example, while the subject produced many consonant and vowel deletion errors when these were part of consonant and vowel clusters, respectively (e.g., sfondo----sondo; giunta----gunta), deletions were virtually never produced for single consonants flanked by two vowels (e.g., onesto----oesto) or for single vowels flanked by two consonants (e.g., tirare----trare). The demonstration that graphosyllabic factors affect spelling performance disconfirms the hypothesis that graphemic representations consist simply of linearly ordered sets of graphemes. It is concluded that graphemic representations are multidimensional structures: one dimension specifies the grapheme identities that comprise the spelling of a word; a second dimension specifies the consonant/vowel status of the graphemes; a third dimension represents the graphosyllabic structure of the grapheme string; and, a fourth dimension provides information about geminate features.     

The role of duration and rapid temporal processing on the lateral perception of consonants and vowels

This study explored the extent to which rapid temporal processing and duration contribute to the right-ear advantage (REA) and presumably left-hemisphere processing for stop consonants and the lack of clear-cut laterality effects for vowels. Three sets of synthetic stimuli were constructed: consonant vowel stimuli [ba da ga bi di gi bu du gu] of 300 msec duration (full stimuli) and two shortened stimuli consisting either of a noise burst and 40-msec transitions (40-msec stimuli), or a noise burst and 20-msec transitions (20-msec stimuli). Stimuli were presented dichotically for consonant, vowel, and syllable identification. Results indicated a significant REA for consonants in the full and 40-msec conditions and a non-significant REA in the 20-msec condition. Nevertheless, the magnitude of laterality did not change across the three conditions. These results suggest that although transition information including duration contributes to lateralization for stop consonants, it is the presence of abrupt onsets which crucially determines lateralized processing. For vowels, there was a significant REA only in the full stimulus condition, and a significant decrement in the magnitude of the laterality effect in the two shortened stimulus conditions. These results suggest that for vowel perception, it is the nature of the acoustic cue used for phonetic identification and not duration that seems to be the critical determinant of lateralization effects.     

What can megastudies tell us about the orthographic structure of English words?

Although the majority of research in visual word recognition has targeted single-syllable words, most words are polysyllabic. These words engender special challenges, one of which concerns their analysis into smaller units. According to a recent hypothesis, the organization of letters into groups of successive consonants (C) and vowels (V) constrains the orthographic structure of printed words. So far, evidence has been reported only in French with factorial studies of relatively small sets of items. In the present study, we performed regression analyses on corpora of megastudies (English and British Lexicon Project databases) to examine the influence of the CV pattern in English. We compared hiatus words, which present a mismatch between the number of syllables and the number of groups of adjacent vowel letters (e.g., client), to other words, controlling for standard lexical variables. In speeded pronunciation, hiatus words were processed more slowly than control words, and the effect was stronger in low-frequency words. In the lexical decision task, the interference effect of hiatus in low-frequency words was balanced by a facilitatory effect in high-frequency words. Taken together, the results support the hypothesis that the configuration of consonant and vowel letters influences the processing of polysyllabic words in English.     

Connectionist modelling of the separable processing of consonants and vowels

describe two aphasic patients, with impaired processing of vowels and consonants, respectively. The impairments could not be captured according to the sonority hierarchy or in terms of a feature level analysis. Caramazza et al. claim that this dissociation demonstrates separate representation of the categories of vowels and consonants in speech processing. We present two connectionist models of the management of phonological representations. The models spontaneously develop separable processing of vowels and consonants. The models have two hidden layers and are given as input vowels and consonants represented in terms of their phonological distinctive features. The first model is presented with feature bundles one at a time and the hidden layers have to combine their output to reproduce a unified copy of the feature bundle. In the second model a "fine-coded" layer receives information about feature bundles in isolation, and a "coarse-coded" layer receives information about each feature bundle in the context of the prior and subsequent feature bundle. Coarse-coding facilitated processing of vowels and fine-coding processing of consonants. These models show that separable processing of vowels and consonants is an emergent effect of modular processors operating on feature-based representations. We argue that it is not necessary to postulate an independent level of representation for the consonant/vowel distinction, separate from phonological distinctive features.     

Vowel mutability and lexical selection in English: Evidence from a word reconstruction task

Laboratoire de Sciences Cognitives et Psycholinguistique, Paris, France This study introduces a new paradigm for investigating lexical processing. First, an analysis of data from a series of word-spotting experiments is presented suggesting that listeners treat vowels as more mutable than consonants in auditory word recognition in English. In order to assess this hypothesis, a word reconstruction task was devised in which listeners were required to turn word-like nonwords into words by adapting the identity of either one vowel or one consonant. Listeners modified vowel identity more readily than consonant identity. Furthermore, incorrect responses more often involved a vowel change than a consonant change. These findings are compatible with the proposal that English listeners are equipped to deal with vowel variability by assuming that vowel identity is comparatively underdefined. The results are discussed in the light of theoretical accounts of speech processing.     

The quest for generalizations over consonants: Asymmetries between consonants and vowels are not the by-product of acoustic differences

Consonants and vowels may play different roles during language processing, consonants being preferentially involved in lexical processing, and vowels tending to mark syntactic constituency through prosodic cues. In support of this view, artificial language learning studies have demonstrated that consonants (C) support statistical computations, whereas vowels (V) allow certain structural generalizations. Nevertheless, these asymmetries could be mere by-products of lower level acoustic differences between Cs and Vs, in particular the energy they carry, and thus their relative salience. Here we address this issue and show that vowels remain the preferred targets for generalizations, even when consonants are made highly salient or vowels barely audible. Participants listened to speech streams of nonsense CVCVCV words, in which consonants followed a simple ABA structure. Participants failed to generalize this structure over sonorant consonants (Experiment 1), even when vowel duration was reduced to one third of that of consonants (Experiment 2). When vowels were eliminated from the stream, participants showed only a marginal evidence of generalizations (Experiment 4). In contrast, participants readily generalized the structure over barely audible vowels (Experiment 3). These results show that different roles of consonants and vowels cannot be readily reduced to acoustical and perceptual differences between these phonetic categories.     

Testing the two-cycle model by different word types

The two-cycle model assumes that consonants in words are processed more quickly than vowels. This study tested the two-cycle model with different word types using a priming task which presented consonants or vowels before the target. Analysis showed presenting consonants before the target was beneficial in processing the target for the words with the letter compositions of CWC and CVCV. In contrast, presenting vowels before the target was beneficial for the words with the letter composition of VCVC. The words with the letter composition of VCCV showed no difference between the consonant prime and the vowel prime. The two-cycle model was not supported across all types of words.     

The relation between discriminability and memory for vowels,consonants, and silent-center vowels

People remember lists of vowel-contrasting syllables better than lists that vary only in stop consonant identity. Most views suggest that this difference is due to the structure of immediate memory and the greater discriminability of vowels compared with consonants. In all of these views, there is a presumed systematic relationship between discriminability and recall so that the more discriminable an item, the better that item should be recalled. The 11 experiments reported here measured the relative discriminability of and compared serial recall for (1) intact syllables that varied only in the medial vowel, (2) intact syllables that varied only in the initial consonant, and (3) syllables with the center vowel replaced by silence (so-called silent-center vowels). When item discriminability, as measured by identification, was equated for consonant-contrasting and silent-center lists, serial recall performance was also equal. However, even when the vowels were less discriminable than the consonants or silentcenter vowels, serial recall performance for the vowels was still better. These results are problematic for theories based on acoustic discriminability but can be explained parsimoniously by Nairne’s (1990) feature model.     

Stop-consonant recognition: Release bursts and formant transitions as functionally equivalent,context-dependent cues

Three experiments assessed the roles of release bursts and formant transitions as acoustic cues to place of articulation in syllable-initial voiced stop consonants by systematically removing them from American English /b,d,g/, spoken before nine different vowels by two speakers, and by transposing the bursts across all vowels for each class of stop consonant. The results showed that bursts were largely invariant in their effect, but carried significant perceptual weight in only one syllable out of 27 for Speaker 1, in only 13 syllables out of 27 for Speaker 2. Furthermore, bursts and transitions tended to be reciprocally related: Where the perceptual weight of one increased, the weight of the other declined. They were thus shown to be functionally equivalent, context-dependent cues, each contributing to the rapid spectral changes that follow consonantal release. The results are interpreted as pointing to the possible role of the front-cavity resonance in signaling place of articulation.     

The processing of consonants and vowels during letter identity and letter position assignment in visual-word recognition: an ERP study

Recent research suggests that there is a processing distinction between consonants and vowels in visual-word recognition. Here we conjointly examine the time course of consonants and vowels in processes of letter identity and letter position assignment. Event related potentials (ERPs) were recorded while participants read words and pseudowords in a lexical decision task. The stimuli were displayed under different conditions in a masked priming paradigm with a 50-ms SOA: (i) identity/baseline condition e.g., chocolate-CHOCOLATE); (ii) vowels-delayed condition (e.g., choc_l_te-CHOCOLATE); (iii) consonants-delayed condition (cho_o_ate-CHOCOLATE); (iv) consonants-transposed condition (cholocate-CHOCOLATE); (v) vowels-transposed condition (chocalote-CHOCOLATE), and (vi) unrelated condition (editorial-CHOCOLATE). Results showed earlier ERP effects and longer reaction times for the delayed-letter compared to the transposed-letter conditions. Furthermore, at early stages of processing, consonants may play a greater role during letter identity processing. Differences between vowels and consonants regarding letter position assignment are discussed in terms of a later phonological level involved in lexical retrieval.