Language discrimination by newborns: Teasing apart phonotactic, rhythmic, and intonational cues

Speech rhythm has long been claimed to be a useful bootstrapping cue in the very first steps of language acquisition. Previous studies have suggested that newborn infants do categorize varieties of speech rhythm, as demonstrated by their ability to discriminate between certain languages. However, the existing evidence is not unequivocal: in previous studies, stimuli discriminated by newborns always contained additional speech cues on top of rhythm. Here, we conducted a series of experiments assessing discrimination between Dutch and Japanese by newborn infants, using a speech resynthesis technique to progressively degrade non-rhythmical properties of the sentences. When the stimuli are resynthesized using identical phonemes and artificial intonation contours for the two languages, thereby preserving only their rhythmic and broad phonotactic structure, newborns still seem to be able to discriminate between the two languages, but the effect is weaker than when intonation is present. This leaves open the possibility that the temporal correlation between intonational and rhythmic cues might actually facilitate the processing of speech rhythm

Perception of linguistic rhythm by newborn infants

Previous studies have shown that newborn infants are able to discriminate between certain languages, and it has been suggested that they do so by categorizing varieties of speech rhythm. However, in order to confirm this hypothesis, it is necessary to show that language discrimination is still performed by newborns when all speech cues other than rhythm are removed. Here, we conducted a series of experiments assessing discrimination between Dutch and Japanese by newborn infants, using a speech resynthesis technique to progressively degrade non-rhythmical properties of the sentences. When the stimuli are resynthesized using identical phonemes and artificial intonation contours for the two languages, thereby preserving only their rhythmic structure, newborns are still able to discriminate the languages. We conclude that new-borns are able to classify languages according to their type of rhythm, and that this ability may help them bootstrap other phonological properties of their native language

Neurobiology of dyslexia : A reinterpretation of the data

Theories of developmental dyslexia differ on how to best interpret the great variety of symptoms (linguistic, sensory, motor) observed in dyslexic individuals. One approach views dyslexia as a specific phonological deficit, which sometimes co-occurs with a more general sensorimotor syndrome. The present review of the neurobiology of dyslexia shows that neurobiological data are indeed consistent with this view, explaining both how a specific phonological deficit might arise, and why a sensorimotor syndrome should be significantly associated with it. This new conceptualisation of the aetiology of dyslexia may generalise to other neuro-developmental disorders, and may further explain heterogeneity within each disorder and co-morbidity between disorders

Acoustic correlates of linguistic rhythm: Perspectives

The empirical grounding of a typology of languages' rhythm is again a hot issue. The currently popular approach is based on the durations of vocalic and intervocalic intervals and their variability. Despite some successes, many questions remain. The main findings still need to be generalised to much larger corpora including many more languages. But a straightforward continuation of the current work faces many difficulties. Perspectives are outlined for future work, including proposals for the cross-linguistic control of speech rate, improvements on the statistical analyses, and prospects raised by automatic speech processing

Developmental dyslexia: specific phonological deficit or general sensorimotor dysfunction?

Dyslexia research is now facing an intriguing paradox: it is becoming increasingly clear that a significant proportion of dyslexics present sensory and motor deficits; however, as this “sensorimotor syndrome” is being studied in greater detail, it is also becoming increasingly clear that sensory and motor deficits will play only a limited role in a general causal explanation of specific reading disability

Language identification with suprasegmental cues: A study based on speech resynthesis

This paper proposes a new experimental paradigm to explore the discriminability of languages, a question which is crucial to the child born in a bilingual environment. This paradigm employs the speech resynthesis technique, enabling the experimenter to preserve or degrade acoustic cues such as phonotactics, syllabic rhythm or intonation from natural utterances. English and Japanese sentences were resynthesized, preserving broad phonotactics, rhythm and intonation (Condition 1), rhythm and intonation (Condition 2), intonation only (Condition 3), or rhythm only (Condition 4). The findings support the notion that syllabic rhythm is a necessary and sufficient cue for French adult subjects to discriminate English from Japanese sentences. The results are consistent with previous research using low-pass filtered speech, as well as with phonological theories predicting rhythmic differences between languages. Thus, the new methodology proposed appears to be well-suited to study language discrimination. Applications for other domains of psycholinguistic research and for automatic language identification are considered

The relationship between motor control and phonology in dyslexic children

Background: The goal of this study was to investigate the automaticity/cerebellar theory of dyslexia. We tested phonological skills and cerebellar function in a group of dyslexic 8-12 year old children and their matched controls. Tests administered included the Phonological Assessment Battery, postural stability, bead threading, finger to thumb and time estimation. Results: Dyslexic children were found to be significantly poorer than the controls at all tasks but time estimation. About 75% of dyslexics were more than one standard deviation below controls in phonological ability, and 50% were similarly impaired in motor skills. However, at least part of the discrepancy in motor skills was due to dyslexic individuals who had additional disorders (ADHD and/or DCD). The absence of evidence for a time estimation deficit also casts doubt on the cerebellar origin of the motor deficiency. About half the dyslexic children didn't have any motor problem, and there was no evidence for a causal relationship between motor skills on the one hand and phonological and reading skills on the other. Conclusion: This study provides partial support for the presence of motor problems in dyslexic children, but does not support the hypothesis that a cerebellar dysfunction is the cause of their phonological and reading impairment

Correlates of linguistic rhythm in the speech signal

Spoken languages have been classified by linguists according to their rhythmic properties, and psycholinguists have relied on this classification to account for infants’ capacity to discriminate languages. Although researchers have measured many speech signal properties, they have failed to identify reliable acoustic characteristics for language classes. This paper presents instrumental measurements based on a consonant/vowel segmentation for eight languages. The measurements suggest that intuitive rhythm types reflect specific phonological properties, which in turn are signaled by the acoustic/phonetic properties of speech. The data support the notion of rhythm classes and also allow the simulation of infant language discrimination, consistent with the hypothesis that newborns rely on a coarse segmentation of speech. A hypothesis is proposed regarding the role of rhythm perception in language acquisition

The psychological reality of rhythm classes: Perceptual studies

Linguists have traditionally classified languages into three rhythm classes, namely stress-timed, syllable-timed and mora-timed languages. However, this classification has remained controversial for various reasons: the search for reliable acoustic cues to the different rhythm types has long remained elusive; some languages are claimed to belong to none of the three classes; and few perceptual studies has bolstered the notion. We have previously proposed an acoustic/phonetic model of the different types of linguistic rhythm, and of their categorisation as such by listeners. Here, we present perceptual experiments that directly test the notion of rhythm classes, our model's predictions, and the question of intermediate languages. Language discrimination experiments were run using a speech resynthesis technique to ensure that only rhythmic cues were available to the subjects. Languages investigated were English, Dutch, Spanish, Catalan and Polish. Our results are consistent with the idea that English and Dutch are stress-timed, Spanish and Catalan are syllable-timed, but Polish seems to be different from any other language studied and thus may constitute a new rhythm class. We propose that perceptual studies tapping the ability to discriminate languages' rhythm are the proper way to generate more empirical data relevant to rhythm typology

Language discrimination by human newborns and by cotton-top tamarin monkeys

Humans, but no other animal, make meaningful use of spoken language. What is unclear, however, is whether this capacity depends on a unique constellation of perceptual and neurobiological mechanisms, or whether a subset of such mechanisms are shared with other organisms. To explore this problem, we conducted parallel experiments on human newborns and cotton-top tamarin monkeys to assess their ability to discriminate unfamiliar languages. Using a habituation-dishabituation procedure, we show that human newborns and tamarins can discriminate sentences from Dutch and Japanese, but not if the sentences are played backwards. Moreover, the cues for discrimination are not present in backward speech. This suggests that the human newborns' tuning to certain properties of speech relies on general processes of the primate auditory system