Michael P. Lynch

Innateness, Experience, and Music Perception

Musical acculturation from infancy to adulthood was studied by testing the abilities of Western 6-month-olds and adults to notice mistunings in melodies based on native Western major, native Western minor, and non-native Javanese pelog scales. Results indicated that infants were similarly able to perceive native and non-native scales. Adults, however, were generally better perceivers of native than non-native scales. These findings suggest that infants are born with an equipotentiality for the perception of scales from a variety of cultures and that subsequent culturally specific experience substantially influences music perception.

The role of prematurity and socioeconomic status in the onset of canonical babbling in infants

The onset of canonical babbling (implying production of well-formed syllables) is a landmark event in the development of the capacity for speech, capping a series of vocal stages of the infants first year of life. Infants who are handicapped with regard to linguistic development are, in some cases, delayed in the onset of speech-like sounds such as canonical syllables. The age of onset of canonical babbling in infants born at risk, either due to prematurity or due to low socioeconomic status (SES) has not been extensively studied. This research, based on a longitudinal investigation of babbling and other motor milestones in term and preterm infants of middle and low SES, indicates that the onset of canonical babbling is robust with regard to such risk factors. Neither preterm infants whose ages were corrected for gestational age, nor infants of low SES were delayed in the onset of canonical babbling. In fact, at corrected ages, the preterm infants appeared to begin canonical babbling earlier than their full-term counterparts. It is suggested that the greater auditory experience of the preterms in this study may account for the early appearance of canonical babbling and hand banging, both of which can be viewed as rhythmic stereotypies that may require auditory feedback for normal development. Other motor milestones studied showed neither delay nor acceleration of onset in the same infants.

Speech-like vocalizations in infancy: an evaluation of potential risk factors [*]

This work reports longitudinal evaluation of the speech-like vocal development of infants born at risk due to prematurity or low socio-economic status (SES) and infants not subject to such risk. Twenty infants were preterm (10 of low SES) and 33 were full term (16 of low SES), and all were studied from 0;4 through 1;6. The study provides the indication that at-risk infants are not generally delayed in the ability to produce well-formed speech-like sounds as indicated in tape-recorded vocal samples. At the same time, premature infants show a tendency to produce well-formed syllables less consistently than full terms after the point at which parents and laboratory personnel note the onset of the canonical babbling stage (the point after which well-formed syllables are well established in the infant vocal repertoires). Further, even though low SES infants produce well-formed speech-like structures on schedule, they show a reliably lower tendency to vocalize in general, as reflected by fewer utterances per minute in recorded samples.

Systemic hypothermia improves histological and functional outcome after cervical spinal cord contusion in rats.

Hypothermia has been employed during the past 30 years as a therapeutic modality for spinal cord injury (SCI) in animal models and in humans. With our newly developed rat cervical model of contusive SCI, we investigated the therapeutic efficacy of transient systemic hypothermia (beginning 5 minutes post‐injury for 4 hours, 33°C) with gradual rewarming (1°C per hour) for the preservation of tissue and the prevention of injury‐induced functional loss. A moderate cervical displacement SCI was performed in female Fischer rats, and behavior was assessed for 8 weeks. Histologically, the application of hypothermia after SCI resulted in significant increases in normal‐appearing white matter (31% increase) and gray matter (38% increase) volumes, greater preservation (four‐fold) of neurons immediately rostral and caudal to the injury epicenter, and enhanced sparing of axonal connections from retrogradely traced reticulospinal neurons (127% increase) compared with normothermic controls. Functionally, a faster rate of recovery in open field locomotor ability (BBB score, weeks 1–3) and improved forelimb strength, as measured by both weight‐supported hanging (43% increase) and grip strength (25% increase), were obtained after hypothermia. The current study demonstrates that mild systemic hypothermia is effective for retarding tissue damage and reducing neurological deficits following a clinically relevant contusive cervical SCI. J. Comp. Neurol. 514:433–448, 2009.

A study of perceptual development for musical tuning

Musical tuning perception in infancy and adulthood was explored in three experiments. In Experiment 1, Western adults were tested in detection of randomly located mistunings in a melody based on musical interval patterns from native and nonnative musical scales. Subjects performed better in a Western major scale context than in either a Western augmented or--a Javanese pelog scale context. Because the major scale is used frequently in Western music and, therefore, is more perceptually familiar than either the augmented scale or the pelog scale are, the adults’ pattern of performance is suggestive of musical acculturation. Experiments 2 and3 were designed to explore the onset of culturally specific perceptual reorganization for music in the age period that has been found to be important in linguistically specific perceptual reorganization for speech. In Experiment 2, 1-year-olds had a pattern of performance similar to that of the adults, but 6-month-olds could not detect mistunings reliably better than chance. In Experiment 3, another group of 6-month-olds was tested, and a larger degree of mistuning was used so that floor effects might be avoided. These 6-month-olds performed better in the major and augmented scale contexts than in the pelog context, without a reliable performance difference between the major and augmented contexts. Comparison of the results obtained with 6-month-olds and 1-year-olds suggests that culturally specific perceptual reorganization for musical tuning begins to affect perception between these ages, but the 6-month-olds’ pattern of results considered alone is not as clear. The 6-month-olds’ better performance on the major and augmented interval patterns than on the pelog interval pattern is potentially attributable to either the 6-month.olds’ lesser perceptual acculturation than that of the 1-year-olds or perhaps to an innate predisposition for processing of music based on a single fundamental interval, in this case the semitone.

Development of Speech-like Vocalizations in a Child with Congenital Absence of Cochleas: The Case of Total Deafness.

In order to assess the effect of total deafness on vocalization development, tape recorded utterances of a 3-year-old child who was born without cochleas were examined. In the beginning of the study, the subjects speech consisted almost exclusively of small numbers of sounds characteristic of early infancy. Across the study, the subject participated in extensive vocal stimulation activities. He also initially received intermittent exposure to tactile speech information via a 16-channel vocoder and, subsequently, a 2-channel tactile aid. Following introduction of the 2-channel aid, the subject made rapid improvement in the quality of his vocalizations, which consisted increasingly of speech-like utterances, including well-formed or canonical syllables. These results suggest that, although hearing impairment slows the onset of canonical babbling, even total deafness does not preclude its eventual appearance.

Perspectives on Early Language from Typical Development and Down Syndrome

Publisher Summary The developing infants and children achieve major perceptual and productive developments in the first few years of life. This chapter provides an overview of perceptual and productive abilities of the developing infants and children for language in the first few years of life. It presents what is known about language development in this age period for Down syndrome to highlight potentially important descriptive gaps. Thereafter, it discusses infant vocalizations, early semantic development, syntactic development, and relationships with language comprehension. Infants can perceive speech sounds in a categorical-like manner, combine visual and auditory input in speech perception, and extract the underlying rhythmic and musical interval structures from tone sequences. In the visually reinforced infant speech discrimination paradigm, Down syndrome infants younger than one year seem unable to establish the necessary connection between a change in the auditory stimulus and the presentation of a visual reinforce. Description of the early language difficulties of Down syndrome children may result in the development of effective strategies for augmenting the language development of these children that may not be possible later in life.

And what of human musicality

This target article presents a plausible evolutionary scenario for the emergence of the neural preconditions for language in the hominid lineage. In pleistocene primate lineages there was a paired evolutionary expansion of frontal and parietal neocortex (through certain well-documented adaptive changes associated with manipulative behaviors) resulting, in ancestral hominids, in an incipient Brocas region and in a configurationally unique junction of the parietal, occipital, and temporal lobes of the brain (the POT). In our view, the development of the POT in our ancestors resulted in the neuroanatomical substrate consistent with the ability for representations in modality-neutral association cortex and, as a result of structure-imposing interaction with Brocas area, the hierarchically structured conceptual structure. Evidence from paleoneurology and comparative primate neuroanatomy is used to argue that Homo habilis (2.5-2 million years ago) was the first hominid to have the appropriate gross neuroanatomical configuration to support conceptual structure. We thus suggest that the neural preconditions for language are met in H. habilis. Finally, we advocate a theory of language acquisition that uses conceptual structure as input to the learning procedures, thus bridging the gap between it and language.

Early musical acculturation

Humans can universally, under typical circumstances, appreciate music. This appreciation is presumably dependent on the ability to process musical structure, but it is not clear how this processing develops. The present study was designed to contribute toward clarification of this issue. Western infants were tested in detection of mistunings (increase of 3.2% in frequency of a randomly selected melody note) in melodies based on either native or nonnative musical scales. Infants repeatedly heard the well‐tuned versions of the melodies and learned to turn their heads toward the sound source when they heard a mistuning. If infants, like adults, have developed schematic knowledge of musical tuning, then their performance in this task would be expected to be better in testing conditions involving native scales than in conditions involving nonnative scales. Although infants at 6, 9, and 12 months of age all performed the task with reliably better than chance success, statistically better native than nonnative m...

Development of the infrastructure of phonological systems.

Insightful description of infant vocal development requires a framework that allows comparison of the vocal units of infant sounds to a comparable level of structure in mature speech systems. The infrastructure of phonological systems can be accounted for by focusing on essential components of acoustics/articulation of each tier of the natural rhythmic hierarchy of speech. The hierarchy includes at least syllable, foot, line, and verse tiers, all of which can be characterized in terms of essential properties (e.g., allowable durations, resonances, F0 patterns). Having once established the infraphonogical properties of elements at a variety of levels, it is possible to describe infant vocalizations in terms of those properties and to discern important patterns of development in infants−stages of development that correspond to the mastery of different parts of the infrastructural scheme. In addition, in the context of such description, certain key differences in the development of normal and handicapped inf...