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Biomedical subjects

Patricia K Kuhl

Publications and source records attributed to Patricia K Kuhl.

17 recordsLinked to original sources
PubMed2007

Clarifying the associations between language and social development in autism: a study of non-native phoneme recognition.

Autism spectrum disorders (ASDs) are characterized by correlated deficiencies in social and language development. This study explored a fundamental aspect of auditory information processing (AIP) that is dependent on social experience and critical to early language development: the ability to compartmentalize close-sounding speech sounds into singular phonemes. We examined this ability by assessing whether close-sounding non-native language phonemes were more likely to be perceived as disparate sounds by school-aged children with high-functioning ASD (n = 27), than by unaffected control subjects (n = 35). No significant group differences were observed. Although earlier in autistic development there may exist qualitative deficits in this specific aspect of AIP, they are not an enduring characteristic of verbal school-aged children with ASD.

Asperger Syndrome↗
PubMed2007

Is speech learning 'gated' by the social brain?

I advance the hypothesis that the earliest phases of language acquisition -- the developmental transition from an initial universal state of language processing to one that is language-specific -- requires social interaction. Relating human language learning to a broader set of neurobiological cases of communicative development, I argue that the social brain 'gates' the computational mechanisms involved in human language learning.

Animals↗
PubMed2006

Infant speech perception activates Broca's area: a developmental magnetoencephalography study.

Discriminative responses to tones, harmonics, and syllables in the left hemisphere were measured with magnetoencephalography in neonates, 6-month-old infants, and 12-month-old infants using the oddball paradigm. Real-time head position tracking, signal space separation, and head position standardization were applied to secure quality data for source localization. Minimum current estimates were calculated to characterize infants' cortical activities for detecting sound changes. The activation patterns observed in the superior temporal and inferior frontal regions provide initial evidence for the developmental emergence early in life of a perceptual-motor link for speech perception that may depend on experience.

Acoustic Stimulation↗
PubMed2006

Infants show a facilitation effect for native language phonetic perception between 6 and 12 months.

Patterns of developmental change in phonetic perception are critical to theory development. Many previous studies document a decline in nonnative phonetic perception between 6 and 12 months of age. However, much less experimental attention has been paid to developmental change in native-language phonetic perception over the same time period. We hypothesized that language experience in the first year facilitates native-language phonetic performance between 6 and 12 months of age. We tested 6-8- and 10-12-month-old infants in the United States and Japan to examine native and nonnative patterns of developmental change using the American English /r-l/ contrast. The goals of the experiment were to: (a) determine whether facilitation characterizes native-language phonetic change between 6 and 12 months of age, (b) examine the decline previously observed for nonnative contrasts and (c) test directional asymmetries for consonants. The results show a significant increase in performance for the native-language contrast in the first year, a decline in nonnative perception over the same time period, and indicate directional asymmetries that are constant across age and culture. We argue that neural commitment to native-language phonetic properties explains the pattern of developmental change in the first year.

Age Factors↗
PubMed2006

Perception of native and non-native affricate-fricative contrasts: cross-language tests on adults and infants.

Previous studies have shown improved sensitivity to native-language contrasts and reduced sensitivity to non-native phonetic contrasts when comparing 6-8 and 10-12-month-old infants. This developmental pattern is interpreted as reflecting the onset of language-specific processing around the first birthday. However, generalization of this finding is limited by the fact that studies have yielded inconsistent results and that insufficient numbers of phonetic contrasts have been tested developmentally; this is especially true for native-language phonetic contrasts. Three experiments assessed the effects of language experience on affricate-fricative contrasts in a cross-language study of English and Mandarin adults and infants. Experiment 1 showed that English-speaking adults score lower than Mandarin-speaking adults on Mandarin alveolo-palatal affricate-fricative discrimination. Experiment 2 examined developmental change in the discrimination of this contrast in English- and Mandarin-leaning infants between 6 and 12 months of age. The results demonstrated that native-language performance significantly improved with age while performance on the non-native contrast decreased. Experiment 3 replicated the perceptual improvement for a native contrast: 6-8 and 10-12-month-old English-learning infants showed a performance increase at the older age. The results add to our knowledge of the developmental patterns of native and non-native phonetic perception.

Acoustic Stimulation↗
PubMed2005

Sentence processing in 30-month-old children: an event-related potential study.

In a previous event-related brain potential study, we provided evidence that preschoolers display different brain electrical patterns to semantic content and syntactic structure processing. In the present study, we aimed to determine the time-course of these event-related potential effects in 30-month-old children, using the same syntactically anomalous, semantically anomalous and control sentences that we used in our previous study. The results show that semantic violations elicit a frontal negativity peaking around 600 ms, whereas the morphosyntactic violations elicit a slow positive shift peaking around 800 ms with a frontocentral distribution. Our findings replicate the event-related potential patterns previously observed in young children and indicate that the neural signatures of sentence processing can be observed at an early point in development.

Acoustic Stimulation↗
PubMed2005

Effects of language experience: neural commitment to language-specific auditory patterns.

Linguistic experience alters an individual's perception of speech. We here provide evidence of the effects of language experience at the neural level from two magnetoencephalography (MEG) studies that compare adult American and Japanese listeners' phonetic processing. The experimental stimuli were American English /ra/ and /la/ syllables, phonemic in English but not in Japanese. In Experiment 1, the control stimuli were /ba/ and /wa/ syllables, phonemic in both languages; in Experiment 2, they were non-speech replicas of /ra/ and /la/. The behavioral and neuromagnetic results showed that Japanese listeners were less sensitive to the phonemic /r-l/ difference than American listeners. Furthermore, processing non-native speech sounds recruited significantly greater brain resources in both hemispheres and required a significantly longer period of brain activation in two regions, the superior temporal area and the inferior parietal area. The control stimuli showed no significant differences except that the duration effect in the superior temporal cortex also applied to the non-speech replicas. We argue that early exposure to a particular language produces a "neural commitment" to the acoustic properties of that language and that this neural commitment interferes with foreign language processing, making it less efficient.

Acoustic Stimulation↗
PubMed2005

Neural patterns to speech and vocabulary growth in American infants.

We report infant auditory event-related potentials to native and foreign contrasts. Foreign contrasts are discriminated at 11 months of age, showing significant differences between the standard and deviant over the positive (P150-250), or over the negative (N250-550) part of the waveform. The amplitudes of these deflections have different amplitude scalp distributions. Infants were followed up longitudinally at 18, 22, 25, 27 and 30 months for word production. The infant speech discriminatory P150-250 and N250-550 are different components with different implications for later language development.

Acoustic Stimulation↗
PubMed2005

Links between social and linguistic processing of speech in preschool children with autism: behavioral and electrophysiological measures.

Data on typically developing children suggest a link between social interaction and language learning, a finding of interest both to theories of language and theories of autism. In this study, we examined social and linguistic processing of speech in preschool children with autism spectrum disorder (ASD) and typically developing chronologically matched (TDCA) and mental age matched (TDMA) children. The social measure was an auditory preference test that pitted 'motherese' speech samples against non-speech analogs of the same signals. The linguistic measure was phonetic discrimination assessed with mismatch negativity (MMN), an event-related potential (ERP). As a group, children with ASD differed from controls by: (a) demonstrating a preference for the non-speech analog signals, and (b) failing to show a significant MMN in response to a syllable change. When ASD children were divided into subgroups based on auditory preference, and the ERP data reanalyzed, ASD children who preferred non-speech still failed to show an MMN, whereas ASD children who preferred motherese did not differ from the controls. The data support the hypothesis of an association between social and linguistic processing in children with ASD.

Autistic Disorder↗
PubMed2005

Brain potentials to native and non-native speech contrasts in 7- and 11-month-old American infants.

Abstract Behavioral data establish a dramatic change in infants' phonetic perception between 6 and 12 months of age. Foreign-language phonetic discrimination significantly declines with increasing age. Using a longitudinal design, we examined the electrophysiological responses of 7- and 11-month-old American infants to native and non-native consonant contrasts. Analyses of the event-related potentials (ERP) of the group data at 7 and at 11 months of age demonstrated that infants' discriminatory ERP responses to the non-native contrast are present at 7 months of age but disappear by 11 months of age, consistent with the behavioral data reported in the literature. However, when the same infants were divided into subgroups based on individual ERP components, we found evidence that the infant brain remains sensitive to the non-native contrast at 11 months of age, showing differences in either the P150-250 or the N250-550 time window, depending upon the subgroup. Moreover, we observed an increase in infants' responsiveness to native language consonant contrasts over time. We describe distinct neural patterns in two groups of infants and suggest that their developmental differences may have an impact on language development.

Acoustic Stimulation↗
PubMed2005

The effect of reduced vowel working space on speech intelligibility in Mandarin-speaking young adults with cerebral palsy.

The purpose of this study was to examine the effect of reduced vowel working space on dysarthric talkers' speech intelligibility using both acoustic and perceptual approaches. In experiment 1, the acoustic-perceptual relationship between vowel working space area and speech intelligibility was examined in Mandarin-speaking young adults with cerebral palsy. Subjects read aloud 18 bisyllabic words containing the vowels /i/, /a/, and /u/ using their normal speaking rate. Each talker's words were identified by three normal listeners. The percentage of correct vowel and word identification were calculated as vowel intelligibility and word intelligibility, respectively. Results revealed that talkers with cerebral palsy exhibited smaller vowel working space areas compared to ten age-matched controls. The vowel working space area was significantly correlated with vowel intelligibility (r=0.632, p<0.005) and with word intelligibility (r=0.684, p<0.005). Experiment 2 examined whether tokens of expanded vowel working spaces were perceived as better vowel exemplars and represented with greater perceptual spaces than tokens of reduced vowel working spaces. The results of the perceptual experiment support this prediction. The distorted vowels of talkers with cerebral palsy compose a smaller acoustic space that results in shrunken intervowel perceptual distances for listeners.

Adolescent↗
PubMed2004

An event-related brain potential study of sentence comprehension in preschoolers: semantic and morphosyntactic processing.

The goal of this study was to investigate the distinctiveness and the relative time course of the event-related brain potentials (ERP) elicited by syntactically and semantically anomalous words within sentences in 36- and 48-month-old children. ERPs were recorded while children listened to semantically anomalous (i.e., My uncle will blow the movie*), syntactically anomalous (i.e., My uncle will watching the movie*) and control sentences (i.e., My uncle will watch the movie). Semantic violations elicited a negative slow wave with different peaks at 400, 600 and 800 ms in both age groups, whereas the morphosyntactic violations elicited two positive shifts: the first starting at 200 ms with a frontal distribution over the scalp and the second starting at 600 ms and peaking around 800 ms with a broad distribution across the scalp in 36-month-olds and anteriorly distributed for 48-month-olds. These results show that preschoolers display different ERP patterns to syntactic and to semantic violations within sentences. It is possible that the ERP effects here reported are analogous to those elicited in adults by the same type of stimuli, although differences in topography are evident.

Acoustic Stimulation↗
PubMed2004

Early language acquisition: cracking the speech code.

Infants learn language with remarkable speed, but how they do it remains a mystery. New data show that infants use computational strategies to detect the statistical and prosodic patterns in language input, and that this leads to the discovery of phonemes and words. Social interaction with another human being affects speech learning in a way that resembles communicative learning in songbirds. The brain's commitment to the statistical and prosodic patterns that are experienced early in life might help to explain the long-standing puzzle of why infants are better language learners than adults. Successful learning by infants, as well as constraints on that learning, are changing theories of language acquisition.

Brain↗
PubMed2003

Foreign-language experience in infancy: effects of short-term exposure and social interaction on phonetic learning.

Infants acquire language with remarkable speed, although little is known about the mechanisms that underlie the acquisition process. Studies of the phonetic units of language have shown that early in life, infants are capable of discerning differences among the phonetic units of all languages, including native- and foreign-language sounds. Between 6 and 12 mo of age, the ability to discriminate foreign-language phonetic units sharply declines. In two studies, we investigate the necessary and sufficient conditions for reversing this decline in foreign-language phonetic perception. In Experiment 1, 9-mo-old American infants were exposed to native Mandarin Chinese speakers in 12 laboratory sessions. A control group also participated in 12 language sessions but heard only English. Subsequent tests of Mandarin speech perception demonstrated that exposure to Mandarin reversed the decline seen in the English control group. In Experiment 2, infants were exposed to the same foreign-language speakers and materials via audiovisual or audio-only recordings. The results demonstrated that exposure to recorded Mandarin, without interpersonal interaction, had no effect. Between 9 and 10 mo of age, infants show phonetic learning from live, but not prerecorded, exposure to a foreign language, suggesting a learning process that does not require long-term listening and is enhanced by social interaction.

Female↗
PubMed2003

A perceptual interference account of acquisition difficulties for non-native phonemes.

This article presents an account of how early language experience can impede the acquisition of non-native phonemes during adulthood. The hypothesis is that early language experience alters relatively low-level perceptual processing, and that these changes interfere with the formation and adaptability of higher-level linguistic representations. Supporting data are presented from an experiment that tested the perception of English /r/ and /l/ by Japanese, German, and American adults. The underlying perceptual spaces for these phonemes were mapped using multidimensional scaling and compared to native-language categorization judgments. The results demonstrate that Japanese adults are most sensitive to an acoustic cue, F2, that is irrelevant to the English /r/-/l/ categorization. German adults, in contrast, have relatively high sensitivity to more critical acoustic cues. The results show how language-specific perceptual processing can alter the relative salience of within- and between-category acoustic variation, and thereby interfere with second language acquisition.

Humans↗
PubMedDate not supplied

Speech perception in infancy predicts language development in the second year of life: a longitudinal study.

Infants' early phonetic perception is hypothesized to play an important role in language development. Previous studies have not assessed this potential link in the first 2 years of life. In this study, speech discrimination was measured in 6-month-old infants using a conditioned head-turn task. At 13, 16, and 24 months of age, language development was assessed in these same children using the MacArthur Communicative Development Inventory. Results demonstrated significant correlations between speech perception at 6 months of age and later language (word understanding, word production, phrase understanding). The finding that speech perception performance at 6 months predicts language at 2 years supports the idea that phonetic perception may play an important role in language acquisition.

Child↗