Word Onset Research Articles

Lexically biased perceptual adaptation

Listeners are able to rapidly shift their acoustic-phonetic categories in the face of speaker-specific variation. However, an open question is how top-down expectations can influence this perceptual adaptation. Under Adaptive Resonance Theory [Grossberg (2003)], if an acoustic token provides initial activation of a linguistic category, top-down expectations about that category can boost the resonance and lead to activation of the category even with an ambiguous token. Ambiguous tokens in positions with stronger expectations are hypothesized to lead to less perceptual adaptation than in positions with lower expectations. To test this hypothesis, two groups of participants will be exposed to 10 ambiguous s-∫ sounds during a lexical decision exposure task. The groups differ in where in the word these sounds will occur, either in the onset or coda of CVC words. Lexical bias, as a form of top-down expectations, is stronger for ambiguous coda sounds [Pitt and Szostak (2012)]. I predict that in a s-∫ categorization task following exposure, the coda group will differ less than the onset group from a control group that only completes the categorization task, indicative of less perceptual adaptation.

Eye movements reveal differences in children’s referential processing during narrative comprehension

Children differ in their ability to build referentially coherent discourse representations. Using a visual world paradigm, we investigated how these differences might emerge during the online processing of spoken discourse. We recorded eye movements of 69children (6–11years of age) as they listened to a 7-min story and concurrently viewed a display containing line drawings of the protagonists. Throughout the story, the protagonists were referenced by either a name (e.g., rabbit) or an anaphoric pronoun (e.g., he). Results showed that the probability of on-target fixations increased after children heard a proper name, but not after they heard an anaphoric pronoun. However, differences in the probability of on-target fixation at word onset indicate that the referents of anaphoric pronouns were anticipated by good comprehenders, but less so by poor comprehenders. These findings suggest that comprehension outcomes are related to the online processing of discourse-level cues that regulate the accessibility of entities.

English Listeners’ Use of Distributional and Acoustic-Phonetic Cues to Liaison in French: Evidence from Eye Movements

This study investigates English listeners’ use of distributional and acoustic-phonetic cues to liaison in French. Liaison creates a misalignment of the syllable and word boundaries, but is signaled by distributional cues (/z/ is a frequent liaison but not a frequent word onset; /t/ is a frequent word onset but a less frequent liaison) and acoustic-phonetic cues (liaison consonants are 15 per cent shorter than word-initial consonants). English-speaking French learners completed a visual-world eye-tracking experiment in which they heard adjective-noun sequences where the pivotal consonant was /t/ (expected advantage for consonant-initial words) or /z/ (expected advantage for liaison-initial words). Their results were compared to those of native French speakers. Both groups showed an advantage for consonant-initial targets with /t/ but no advantage for consonant- or liaison-initial targets with /z/. Both groups’ competitor fixations were modulated by the duration of the pivotal consonant, but only the learners’ fixations to liaison-initial targets were modulated by the duration of the pivotal consonant. This suggests that English listeners use both top-down (distributional) and bottom-up (acoustic-phonetic) cues to liaison in French. Their greater reliance on acoustic-phonetic cues is hypothesized to stem in part from English, where such cues play an important role for locating word boundaries.

Erroneous and correct actions have a different affective valence: Evidence from ERPs.

The accuracy of actions is swiftly determined through specific monitoring brain systems. Event-related potential (ERP) studies have shown that error commission is associated with the generation of the error-related negativity (ERN/Ne), whereas correct actions are associated with the correct-related negativity (CRN). Although the exact functional meaning of the ERN/Ne (and CRN) component remains debated, some authors have suggested that it reflects the processing of the emotional significance of actions. However, no study to date has directly linked amplitude changes at the level of the ERN/Ne-CRN to the affective processing of actions. To decode the emotional valence of actions performed during a go/no-go task, the authors used an evaluative priming method in this study. After each action following the go/no-go stimulus, participants had to categorize an evaluative word as either positive or negative. Behavioral results showed that response errors (i.e., false alarms, FAs) performed during the go/no-go task led to a faster categorization of negative than positive words. Remarkably, this evaluative priming effect was related to the magnitude of the ERN/Ne component generated during the go/no-go task. Moreover, ERP results showed that the processing of evaluative words following FAs was influenced early on after word onset (early posterior negativity-EPN effect), while it was influenced later following correct as well as incorrect actions (late positive potential-LPP effect). Altogether, these ERP results suggest that the action-related ERN-CRN component encodes the perceived emotional significance of actions, such that early stages of evaluative word processing following these actions are influenced by this automatic process.

Parallel language activation and cognitive control during spoken word recognition in bilinguals

Accounts of bilingual cognitive advantages suggest an associative link between crosslinguistic competition and inhibitory control. We investigate this link by examining English-Spanish bilinguals' parallel language activation during auditory word recognition and nonlinguistic Stroop performance. Thirty-one English-Spanish bilinguals and 30 English monolinguals participated in an eyetracking study. Participants heard words in English (e.g., comb) and identified corresponding pictures from a display that included pictures of a Spanish competitor (e.g., conejo, English rabbit). Bilinguals with higher Spanish proficiency showed more parallel language activation and smaller Stroop effects than bilinguals with lower Spanish proficiency. Across all bilinguals, stronger parallel language activation between 300 and 500 ms after word onset and reduced parallel language activation between 633 and 767 ms after word onset were associated with smaller Stroop effects. Results suggest that bilinguals who perform well on the Stroop task show increased crosslinguistic competitor activation during early stages of word recognition and decreased competitor activation during later stages of word recognition. Findings support the hypothesis that crosslinguistic competition impacts domain-general inhibition.

Longitudinal Study of Early Vocalization Development in Toddlers with and without Cleft Palate from 6 to 18 Months of Age

Objectives: Early vocalization shows a close relationship with speech sound development and influences the onset of first words. This study explored longitudinally early vocalization development in toddlers with and without cleft palate from 6 to 18 months of age. Methods: The participants included 3 toddlers with cleft palate and 3 typically developing toddlers. Their vocalization samples were obtained with 3-month intervals from 6 or 7 to 18 months of age. The vocalization samples were analyzed based on the Stark assessment of early vocal development-revised and measures on vocalization types and each vocalization ratio were obtained. Results: Results indicated that group differences were observed in the ratio of level 2 at 18 months of age; toddlers with cleft palate exhibited a larger ratio of level 2 vocalization at 18 months of age. Two toddlers with cleft palate showed delayed vocalization developmental patterns during the entire period of the study. Toddlers with cleft palate showed decreases in level 2 which includes fully-resonant nuclei and two closant- vocant combinations. However, they did not exhibit remarkable changes in level 4 and 5 which include single consonant-vowel syllable, repeated canonical syllable, and jargon. Typically developing toddlers showed decreases in level 2 vocalization and progressive increases in level 4 and 5. Conclusion: This study suggested that toddlers with cleft palate generally showed delayed vocalization development compared to typically developing toddlers. The study results have implications for monitoring the development of pre-linguistic vocalization in toddlers with cleft palate.

On the nature of sonority in spoken word production: Evidence from neuropsychology

The concept of sonority – that speech sounds can be placed along a universal sonority scale that affects syllable structure – has proved valuable in accounting for a wide spectrum of linguistic phenomena and psycholinguistic findings. Yet, despite the success of this concept in specifying principles governing sound structure, several questions remain about sonority. One issue that needs clarification concerns its locus in the processes involved in spoken language production, and specifically whether sonority affects the computation of abstract word form representations (phonology), the encoding of context-specific features (phonetics), or both of these processes. This issue was examined in the present study investigating two brain-damaged individuals with impairment arising primarily from deficits affecting phonological and phonetic processes, respectively. Clear effects of sonority on production accuracy were observed in both individuals testing word onsets and codas in word production. These findings indicate that the underlying principles governing sound structure that are captured by the notion of sonority play a role at both phonological and phonetic levels of processing. Furthermore, aspects of the errors recorded from our participants revealed features of syllabic structure proposed under current phonological theories (e.g., articulatory phonology).

Speech-Specific Tuning of Neurons in Human Superior Temporal Gyrus

How the brain extracts words from auditory signals is an unanswered question. We recorded approximately 150 single and multi-units from the left anterior superior temporal gyrus of a patient during multiple auditory experiments. Against low background activity, 45% of units robustly fired to particular spoken words with little or no response to pure tones, noise-vocoded speech, or environmental sounds. Many units were tuned to complex but specific sets of phonemes, which were influenced by local context but invariant to speaker, and suppressed during self-produced speech. The firing of several units to specific visual letters was correlated with their response to the corresponding auditory phonemes, providing the first direct neural evidence for phonological recoding during reading. Maximal decoding of individual phonemes and words identities was attained using firing rates from approximately 5 neurons within 200 ms after word onset. Thus, neurons in human superior temporal gyrus use sparse spatially organized population encoding of complex acoustic-phonetic features to help recognize auditory and visual words.

What you see is what you hear: How visual prosody affects artificial language learning in adults and children

Speech perception is a multimodal phenomenon, with what we see impacting what we hear. In this study, we examine how visual information impacts English listeners’ segmentation of words from an artificial language containing no cues to word boundaries other than the transitional probabilities (TPs) between syllables. Participants (N = 60) were assigned to one of three conditions: Still (still image), trochaic (image loomed toward the listener at syllable onsets), or Iambic (image loomed toward the listener at syllable offsets). Participants also heard either an easy or difficult variant of the language. Importantly, both languages lacked auditory prosody. Overall performance in a 2AFC test was better in the easy (67%) than difficult language (57%). In addition, across languages, listeners performed best in the trochaic condition (67%) and worst in the Iambic condition (56%). Performance in the still condition fell in between (61%). We know English listeners perceive strong syllables as word onsets. Thus, participants likely found the Trochaic Condition easiest because the moving image led them to perceive temporally co-occurring syllables as strong. We are currently testing 6-year-olds (N = 25) with these materials. Thus far, children’s performance collapsed across conditions is similar to adults (60%). However, visual information may impact children's performance less.

Expectation and Entropy in Spoken Word Recognition: Effects of Age and Hearing Acuity

Background/Study Context: Older adults, especially those with reduced hearing acuity, can make good use of linguistic context in word recognition. Less is known about the effects of the weighted distribution of probable target and nontarget words that fit the sentence context (response entropy). The present study examined the effects of age, hearing acuity, linguistic context, and response entropy on spoken word recognition. Methods: Participants were 18 older adults with good hearing acuity (M age = 74.3 years), 18 older adults with mild-to-moderate hearing loss (M age = 76.1 years), and 18 young adults with age-normal hearing (M age = 19.6 years). Participants heard sentence-final words using a word-onset gating paradigm, in which words were heard with increasing amounts of onset information until they could be correctly identified. Degrees of context varied from a neutral context to a high context condition. Results: Older adults with poor hearing acuity required a greater amount of word onset information for recognition of words when heard in a neutral context compared with older adults with good hearing acuity and young adults. This difference progressively decreased with an increase in words’ contextual probability. Unlike the young adults, both older adult groups’ word recognition thresholds were sensitive to response entropy. Response entropy was not affected by hearing acuity. Conclusion: Increasing linguistic context mitigates the negative effect of age and hearing loss on word recognition. The effect of response entropy on older adults’ word recognition is discussed in terms of an age-related inhibition deficit.

Ambiguity related to French liaisons: The role of bottom-up and top-down processes

French liaison is a phonological process involving the surfacing of an underlying floating consonant as the onset of a vowel-initial word when the word is preceded by a liaison-causing word. We used vowel- and consonant-initial ambiguous targets following four liaison-related contexts /z/, /n/, /t/, /r/ (e.g., ces onches - ces zonches). Targets included nouns and pseudo-nouns. Quebec-French-speaking adults performed two tasks (production, discrimination). One bottom-up (acoustic cues) and three top-down (noun token frequency, word onset probability, contextual liaison knowledge) factors were investigated in the production task. Participants had to produce the last word upon hearing each phrase. Their productions thus reflected their interpretation of the onset of the liaison-ambiguous words. Perception of acoustic cues was also tested in the discrimination task: participants judged if two phrases were different or same. No perception of any acoustical distinction was revealed in the tasks: participants often produced the intended target incorrectly, and differently intended phrasal pairs were judged same (e.g., ces onches - ces zonches). Effects of top-down information were found in the production task. Among the top-down factors, liaison knowledge related to liaison-causing words had a dominant impact on participants’ interpretation of the ambiguous phrases, showing the importance of contextual knowledge in lexical recognition.

Gestural coordination of Italian word-initial clusters: the case of ‘impure s’

We report on an articulatory study which uses an electromagnetic articulograph to investigate word-initial consonant clusters in Italian. In particular, we investigate clusters involving a sibilant, such as inspina‘thorn’. The status of the sibilant in such clusters, referred to as ‘impure s’, is an unresolved problem for the syllable phonology of Italian. Coordination patterns of the gestural targets of consonantal and vocalic gestures reveal a structural difference between obstruent–liquid clusters, e.g. /pr/, and sibilant–obstruent clusters, e.g. /sp/. Whereas in /pr/, both /p/ and /r/ have distinct coordination patterns as compared to either /p/ or /r/ as a single consonant in the same (word-initial) position, this is not the case for /sp/. Here the /p/ patterns like a single consonant: /p/ inspinapatterns with /p/ inPina(proper name). Thus, although /s/ inspinaconstitutes awordonset, there is evidence against it being part of asyllableonset.

L2 perception of Spanish palatal variants across different tasks

While considerable dialectal variation exists, almost all varieties of Spanish exhibit some sort of alternation in terms of the palatal obstruent segments. Typically, the palatal affricate [ɟʝ] tends to occur in word onset following a pause and in specific linear phonotactic environments. The palatal fricative [ʝ] tends to occur in syllable onset in other contexts. We show that listeners’ perceptual sensitivity to the palatal alternation depends upon the task and exposure to Spanish input. For native Spanish listeners, the palatal alternation boosts segmentation accuracy on an artificial speech segmentation task and also reduces latencies on a phonotactically-conditioned elision task. L2 Spanish listeners, on the other hand, only benefit from the palatal alternation in the second task. These results suggest that while Spanish L2 learners benefit from the presence of the alternation in linear phonotactic terms, this benefit does not carry over to a more abstract segmentation task.

Motion words selectively modulate direction discrimination sensitivity for threshold motion

Can speech selectively modulate the sensitivity of a sensory system so that, in the presence of a suitable linguistic context, the discrimination of certain perceptual features becomes more or less likely? In this study, participants heard upward or downward motion words followed by a single visual field of random dots moving upwards or downwards. The time interval between the onsets of the auditory and the visual stimuli was varied parametrically. Motion direction could be either discriminable (suprathreshold motion) or non-discriminable (threshold motion). Participants had to judge whether the dots were moving upward or downward. Results show a double dissociation between discrimination sensitivity (d′) and reaction times depending on whether vertical motion was above or at threshold. With suprathreshold motion, responses were faster for congruent directions of words and dots, but sensitivity was equal across conditions. With threshold motion, sensitivity was higher for congruent directions of words and dots, but responses were equally fast across conditions. The observed differences in sensitivity and response times were largest when the dots appeared 450 ms after word onset, that is, consistently with electrophysiology, at the time the up/down semantics of the word had become available. These data suggest that word meanings can alter the balance between signal and noise within the visual system and affect the perception of low-level sensory features.

Early and parallel processing of pragmatic and semantic information in speech acts: neurophysiological evidence

Although language is a tool for communication, most research in the neuroscience of language has focused on studying words and sentences, while little is known about the brain mechanisms of speech acts, or communicative functions, for which words and sentences are used as tools. Here the neural processing of two types of speech acts, Naming and Requesting, was addressed using the time-resolved event-related potential (ERP) technique. The brain responses for Naming and Request diverged as early as ~120 ms after the onset of the critical words, at the same time as, or even before, the earliest brain manifestations of semantic word properties could be detected. Request-evoked potentials were generally larger in amplitude than those for Naming. The use of identical words in closely matched settings for both speech acts rules out explanation of the difference in terms of phonological, lexical, semantic properties, or word expectancy. The cortical sources underlying the ERP enhancement for Requests were found in the fronto-central cortex, consistent with the activation of action knowledge, as well as in the right temporo-parietal junction (TPJ), possibly reflecting additional implications of speech acts for social interaction and theory of mind. These results provide the first evidence for surprisingly early access to pragmatic and social interactive knowledge, which possibly occurs in parallel with other types of linguistic processing, and thus supports the near-simultaneous access to different subtypes of psycholinguistic information.

Activation of words with phonological overlap.

Multiple lexical representations overlapping with the input (cohort neighbors) are temporarily activated in the listener's mental lexicon when speech unfolds in time. Activation for cohort neighbors appears to rapidly decline as soon as there is mismatch with the input. However, it is a matter of debate whether or not they are completely excluded from further processing. We recorded behavioral data and event-related brain potentials (ERPs) in auditory-visual word onset priming during a lexical decision task. As primes we used the first two syllables of spoken German words. In a carrier word condition, the primes were extracted from spoken versions of the target words (ano-ANORAK “anorak”). In a cohort neighbor condition, the primes were taken from words that overlap with the target word up to the second nucleus (ana—taken from ANANAS “pineapple”). Relative to a control condition, where primes and targets were unrelated, lexical decision responses for cohort neighbors were delayed. This reveals that cohort neighbors are disfavored by the decision processes at the behavioral front end. In contrast, left-anterior ERPs reflected long-lasting facilitated processing of cohort neighbors. We interpret these results as evidence for extended parallel processing of cohort neighbors. That is, in parallel to the preparation and elicitation of delayed lexical decision responses to cohort neighbors, aspects of the processing system appear to keep track of those less efficient word candidates.

Parental reports on early language and motor milestones in fragile X syndrome with and without autism spectrum disorders

Objective: This study examined features of early language and motor milestones in children with fragile X syndrome (FXS) and contrasted these features with a diagnosis of Autism Spectrum Disorder (ASD) later in life in these children.Methods: We retrospectively examined parental report of age of onset for walking and first words for primarily boys with FXS, both with ASD (FXS + ASD) and FXS-only. The diagnosis of ASD was established by DSM-IV criteria, which were complemented by the ADOS. The age of onset was analyzed as a continuous and categorical variable, which were compared to the upper limit of typically developing children.Results: Individuals with FXS-only are more delayed in the onset of first words than first walks. The finding represents a pattern suggesting a continuum as robustly demonstrated in individuals with FXS + ASD vs. FXS-only.Conclusion: Our results support validity of FXS + ASD co-morbidity as a distinct phenotype in individuals with FXS.

Grip force reveals the context sensitivity of language-induced motor activity during "action words" processing: evidence from sentential negation.

BackgroundStudies demonstrating the involvement of motor brain structures in language processing typically focus on time windows beyond the latencies of lexical-semantic access. Consequently, such studies remain inconclusive regarding whether motor brain structures are recruited directly in language processing or through post-linguistic conceptual imagery. In the present study, we introduce a grip-force sensor that allows online measurements of language-induced motor activity during sentence listening. We use this tool to investigate whether language-induced motor activity remains constant or is modulated in negative, as opposed to affirmative, linguistic contexts.Methodology/Principal FindingsParticipants listened to spoken action target words in either affirmative or negative sentences while holding a sensor in a precision grip. The participants were asked to count the sentences containing the name of a country to ensure attention. The grip force signal was recorded continuously. The action words elicited an automatic and significant enhancement of the grip force starting at approximately 300 ms after target word onset in affirmative sentences; however, no comparable grip force modulation was observed when these action words occurred in negative contexts.Conclusions/SignificanceOur findings demonstrate that this simple experimental paradigm can be used to study the online crosstalk between language and the motor systems in an ecological and economical manner. Our data further confirm that the motor brain structures that can be called upon during action word processing are not mandatorily involved; the crosstalk is asymmetrically governed by the linguistic context and not vice versa.

Tracking the Time Course of Word‐Frequency Effects in Auditory Word Recognition With Event‐Related Potentials

Although the word-frequency effect is one of the most established findings in spoken-word recognition, the precise processing locus of this effect is still a topic of debate. In this study, we used event-related potentials (ERPs) to track the time course of the word-frequency effect. In addition, the neighborhood density effect, which is known to reflect mechanisms involved in word identification, was also examined. The ERP data showed a clear frequency effect as early as 350 ms from word onset on the P350, followed by a later effect at word offset on the late N400. A neighborhood density effect was also found at an early stage of spoken-word processing on the PMN, and at word offset on the late N400. Overall, our ERP differences for word frequency suggest that frequency affects the core processes of word identification starting from the initial phase of lexical activation and including target word selection. They thus rule out any interpretation of the word frequency effect that is limited to a purely decisional locus after word identification has been completed.

Available processing resources influence encoding-related brain activity before an event

Effective cognitive functioning not only relies on brain activity elicited by an event, but also on activity that precedes it. This has been demonstrated in a number of cognitive domains, including memory. Here, we show that brain activity that precedes the effective encoding of a word into long-term memory depends on the availability of sufficient processing resources. We recorded electrical brain activity from the scalps of healthy adult men and women while they memorized intermixed visual and auditory words for later recall. Each word was preceded by a cue that indicated the modality of the upcoming word. The degree to which processing resources were available before word onset was manipulated by asking participants to make an easy or difficult perceptual discrimination on the cue. Brain activity before word onset predicted later recall of the word, but only in the easy discrimination condition. These findings indicate that anticipatory influences on long-term memory are limited in capacity and sensitive to the degree to which attention is divided between tasks. Prestimulus activity that affects later encoding can only be engaged when the necessary cognitive resources can be allocated to the encoding process.