Heeding the voice of experience: the role of talker variation in lexical access

Two experiments used the head-mounted eye-tracking methodology to examine the time course of lexical activation in the face of a non-phonemic cue, talker variation. We found that lexical competition was attenuated by consistent talker differences between words that would otherwise be lexical competitors. In Experiment 1, some English cohort word-pairs were consistently spoken by a single talker (male couch, male cows), while other word-pairs were spoken by different talkers (male sheep, female sheet). After repeated instances of talker-word pairings, words from different-talker pairs showed smaller proportions of competitor fixations than words from same-talker pairs. In Experiment 2, participants learned to identify black-and-white shapes from novel labels spoken by one of two talkers. All of the 16 novel labels were VCVCV word-forms atypical of, but not phonologically illegal in, English. Again, a word was consistently spoken by one talker, and its cohort or rhyme competitor was consistently spoken either by that same talker (same-talker competitor) or the other talker (different-talker competitor). Targets with different-talker cohorts received greater fixation proportions than targets with same-talker cohorts, while the reverse was true for fixations to cohort competitors; there were fewer erroneous selections of competitor referents for different-talker competitors than same-talker competitors. Overall, these results support a view of the lexicon in which entries contain extra-phonemic information. Extensions of the artificial lexicon paradigm and developmental implications are discussed.     

On the role of regular phonological variation in lexical access: evidence from voice assimilation in French

The present study investigated whether lexical access is affected by a regular phonological variation in connected speech: voice assimilation in French. Two associative priming experiments were conducted to determine whether strongly assimilated, potentially ambiguous word forms activate the conceptual representation of the underlying word. Would the ambiguous word form [sud] (either assimilated soute 'hold' or soude 'soda') facilitate "bagage" 'luggage', which is semantically related to soute but not to soude? In Experiment 1, words in either canonical or strongly assimilated form were presented as primes. Both forms primed their related target to the same extent. Potential lexical ambiguity did not modulate priming effects. In Experiment 2, the primes such as assimilated soute pronounced [sud] used in Experiment 1 were replaced with primes such as soude canonically pronounced [sud]. No semantic priming effect was obtained with these primes. Therefore, the effect observed for assimilated forms in Experiment 1 cannot be due to overall phonological proximity between canonical and assimilated forms. We propose that listeners must recover the intended words behind the assimilated forms through the exploitation of the remaining traces of the underlying form, however subtle these traces may be.     

Effects of Attention on the Strength of Lexical Influences on Speech Perception: Behavioral Experiments and Computational Mechanisms

The effects of lexical context on phonological processing are pervasive and there have been indications that such effects may be modulated by attention. However, attentional modulation in speech processing is neither well documented nor well understood. Experiment 1 demonstrated attentional modulation of lexical facilitation of speech sound recognition when task and critical stimuli were identical across attention conditions. We propose modulation of lexical activation as a neurophysiologically plausible computational mechanism that can account for this type of modulation. Contrary to the claims of critics, this mechanism can account for attentional modulation without violating the principle of interactive processing. Simulations of the interactive TRACE model extended to include two different ways of modulating lexical activation showed that each can account for attentional modulation of lexical feedback effects. Experiment 2 tested conflicting predictions from the two implementations and provided evidence that is consistent with bias input as the mechanism of attentional control of lexical activation.     

Le voisinage orthographique influence la catégorisation de couleur des mots différemment selon l’âge et la vitesse de traitement

The objective of this research was to determine to what extent the effect of higher-frequency orthographic neighbourhood in a word colour-categorization task is changed during aging when processing speed is taken into account. In addition, the effect of the lexicality of the stimuli on colour categorization was examined, as well as its variation according to age and processing speed. Fifty-two young adults (M_age = 21.62) and 52 older adults (M_age = 66.04) participated in this study. For each age group, two sub-groups were created according to the processing speed of the participants as measured by the WAIS Coding subtest. Two conditions of words (written in red, yellow, green or blue) were presented in a colour-categorization task. Half of the words did not have any orthographic neighbours (e.g., pistil [pistil]), while the other half had a higher-frequency neighbour (e.g., tirade [tirade]/TIRAGE [draw]). A control condition with a series of Xs was added to test the influence of the effect of the lexicality of words on the colour-categorization times. As a whole, the results showed slower colour-categorization times for words compared to a series of Xs, which did not vary with age and processing speed. Importantly, the results showed that orthographic neighbourhood frequency interacted with age and processing speed, on colour categorization response times. More precisely, the neighbourhood frequency effect was found to vary differently according to processing speed in each age group. For the fastest young adults, the facilitatory effect of higher-frequency orthographic neighbourhood was obtained, whereas no such effect was found for the slowest young adults. The fastest older adults did not exhibit any effect of higher-frequency orthographic neighbourhood whereas a facilitatory effect was observed for the slowest older adults. Therefore, these data suggest that both aging and the processing speed of the participants influence the interference effect of reading on colour categorization. These findings are discussed in the context of cognitive aging theories and models of written word recognition.     

Lexical restructuring in the absence of literacy

Vocabulary growth was suggested to prompt the implementation of increasingly finer-grained lexical representations of spoken words in children (e.g., [Metsala, J. L., & Walley, A. C. (1998). Spoken vocabulary growth and the segmental restructuring of lexical representations: precursors to phonemic awareness and early reading ability. In J. L. Metsala & L. C. Ehri (Eds.), Word recognition in beginning literacy (pp. 89-120). Hillsdale, NJ: Erlbaum.]). Although literacy was not explicitly mentioned in this lexical restructuring hypothesis, the process of learning to read and spell might also have a significant impact on the specification of lexical representations (e.g., [Carroll, J. M., & Snowling, M. J. (2001). The effects of global similarity between stimuli on children’s judgments of rime and alliteration. Applied Psycholinguistics, 22, 327-342.]; [Goswami, U. (2000). Phonological representations, reading development and dyslexia: Towards a cross-linguistic theoretical framework. Dyslexia, 6, 133-151.]). This is what we checked in the present study. We manipulated word frequency and neighborhood density in a gating task (Experiment 1) and a word-identification-in-noise task (Experiment 2) presented to Portuguese literate and illiterate adults. Ex-illiterates were also tested in Experiment 2 in order to disentangle the effects of vocabulary size and literacy. There was an interaction between word frequency and neighborhood density, which was similar in the three groups. These did not differ even for the words that are supposed to undergo lexical restructuring the latest (low frequency words from sparse neighborhoods). Thus, segmental lexical representations seem to develop independently of literacy. While segmental restructuring is not affected by literacy, it constrains the development of phoneme awareness as shown by the fact that, in Experiment 3, neighborhood density modulated the phoneme deletion performance of both illiterates and ex-illiterates.     

From grammatical number to exact numbers: early meanings of 'one', 'two', and 'three' in English, Russian, and Japanese

This study examined whether singular/plural marking in a language helps children learn the meanings of the words 'one,' 'two,' and 'three.' First, CHILDES data in English, Russian (which marks singular/plural), and Japanese (which does not) were compared for frequency, variability, and contexts of number-word use. Then young children in the USA, Russia, and Japan were tested on Counting and Give-N tasks. More English and Russian learners knew the meaning of each number word than Japanese learners, regardless of whether singular/plural cues appeared in the task itself (e.g., "Give two apples" vs. "Give two"). These results suggest that the learning of "one," "two" and "three" is supported by the conceptual framework of grammatical number, rather than that of integers.     

The KEY to the ROCK: Near-homophony in nonnative visual word recognition

To test the hypothesis that native language (L1) phonology can affect the lexical representations of nonnative words, a visual semantic-relatedness decision task in English was given to native speakers and nonnative speakers whose L1 was Japanese or Arabic. In the critical conditions, the word pair contained a homophone or near-homophone of a semantically associated word, where a near-homophone was defined as a phonological neighbor involving a contrast absent in the speaker’s L1 (e.g., ROCK-LOCK for native speakers of Japanese). In all participant groups, homophones elicited more false positive errors and slower processing than spelling controls. In the Japanese and Arabic groups, near-homophones also induced relatively more false positives and slower processing. The results show that, even when auditory perception is not involved, recognition of nonnative words and, by implication, their lexical representations are affected by the L1 phonology.     

Impact of auditory selective attention on verbal short-term memory and vocabulary development

This study investigated the role of auditory selective attention capacities as a possible mediator of the well-established association between verbal short-term memory (STM) and vocabulary development. A total of 47 6- and 7-year-olds were administered verbal immediate serial recall and auditory attention tasks. Both task types probed processing of item and serial order information because recent studies have shown this distinction to be critical when exploring relations between STM and lexical development. Multiple regression and variance partitioning analyses highlighted two variables as determinants of vocabulary development: (a) a serial order processing variable shared by STM order recall and a selective attention task for sequence information and (b) an attentional variable shared by selective attention measures targeting item or sequence information. The current study highlights the need for integrative STM models, accounting for conjoined influences of attentional capacities and serial order processing capacities on STM performance and the establishment of the lexical language network.     

Semantic asymmetries are modulated by phonological asymmetries: Evidence from the disambiguation of homophonic versus heterophonic homographs

The present study investigated cerebral asymmetries in accessing multiple meanings of two types of homographs: homophonic homographs (e.g., bank) and heterophonic homographs (e.g., tear). Participants read homographs preceded by either a biasing or a non-biasing sentential context and performed a lexical decision on lateralized targets presented 150 ms after onset of the sentence-final ambiguous prime. Targets were either related to the dominant or the subordinate meaning of the preceding homograph or were unrelated to it. In the case of homophonic homographs – our results converge with previous findings: both activation and selection processes are faster in the LH than in the RH. Importantly, however, in the case of heterophonic homographs – opposite asymmetries were found. These results suggest that semantic asymmetries are modulated by phonology. They are discussed in the context of a model of functional architecture of reading in the two hemispheres in which orthography, phonology and semantics are fully interconnected in the LH, whereas in the RH, orthography and phonology are not directly connected, such that phonological processes are mediated by semantics.