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Deaf children who are unable to acquire oral language naturally and who are not exposed to a standard manual language can spontaneously develop a structured sign system that has many of the properties of natural spoken language. This communication system appears to be largely the invention of the child himself rather than of the caretakers.
Language is a biological trait that radically changed the performance of one species and the appearance of the planet. Understanding how human language came about is one of the most interesting tasks for evolutionary biology. Here we discuss how natural selection can guide the emergence of some basic features of human language, including arbitrary signs, words, syntactic communication and grammar. We show how natural selection can lead to the duality of patterning of human language: sequences of phonemes form words; sequences of words form sentences. Finally, we present a framework for the population dynamics of grammar acquisition, which allows us to study the cultural evolution of grammar and the biological evolution of universal grammar.
A body of medically important work has accumulated in the field of developmental neurolinguistics in the 30 years since Lenneberg set forth a research agenda for that field, consisting of the following: (1) the physiologic specialization or endowment for speech; (2) the genetic origin or natural history of vocalization and speech; (3) the nature of prelinguistic behavior, making possible the detection of any environmental (social) influences; (4) the development of motor-speech organization from birth; and (5) the limiting effects of deficient intelligence, hearing, and environmental stimulation. Subsequent study of these questions has established a genetic, neuroanatomic, and functional basis for such outwardly disparate disorders as dyslexia, stuttering, autism, and delayed language. Studies of emergent motor behavior suggest that babbling may index a state of neural maturation favoring expression of spoken languages. Based on studies of the congenitally deaf, mentally retarded, and other clinical populations it is now considered possible to detect early warning signs of developmental language disorders during the first year of life based on analyses of vocal turn-taking, gesturing, and utterance complexity.
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This study describes the development of the auditory, cognitive, linguistic, and social domains of a child deafened by meningitis at 20 months of age. He received a 3M/House cochlear implant at 27 months and is believed to be the youngest child to receive a cochlear implant. He was seen for intervention emphasizing audiometric conditioning and testing and language (speech and sign) stimulation for a period of 2:9 years (6 months pre-implant to 2:3 years post-implant). Videotapes of intervention; interviews with parents, teachers, and clinicians; test results; and medical and clinical reports were documented from pre-implant to two years post-implantation. The child regressed in all areas evaluated following his illness and subsequent deafness and cochlear implantation. At about one year after implantation, his social and cognitive skills began to improve. By two years after implantation (chronological age (CA) = 4:6), his abilities in all areas except auditory reception and speech had progressed to about the 4:0 age level. He communicates primarily through signs and seems to derive environmental sound and speech duration cues from the implant. Although it is difficult to separate the effects of the implant from maturational factors, he now willingly uses the implant simultaneously with his hearing aid on the non-implanted ear every day and seems to be functioning well with them. He responds inconsistently to his name when called, and consistently provides appropriate signed responses to questions. His imitative skills are improving; he can discriminate one- vs two-syllable words; and produces limited spontaneous speech. His cognitive and social abilities are at least age-appropriate and he signs 3- and 4-word combinations.
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The number of signing authors in Revista Clínica Española. Revista Española de Fisiología and Revista Española de Oncología have been analyzed from their first to the last received issue. The results obtained show an increasing number of authors in all journals specially during the 70s. The results also point out a relative decrease in the number of authors in basic sciences in relation to clinical publications. The increase in the number of authors in The Revista Española de Oncología has started somewhat later than the others. The environmental and professional stress as well as the interrelations between different hospital members have been suggested, amongst others, as the possible cause of these events.
Auditory event-related brain potentials evoked in response to tone stimuli and to speech stimuli were recorded in a group of parents of children with specific language-impairment and a group of parents of normally speaking children. The parents of the language-impaired children showed longer P3 latencies than the parental control group in the speech task requiring a phonological discrimination, but did not differ from the controls in the linguistically non-demanding tone discrimination task. The longer P3 latency was associated with a positive parental history of language delay. There were no group differences concerning the N1 component in any of the tasks. The findings indicate that parents of children with specific language impairment show signs of deficient late-stage perceptual higher order linguistic processing, whereas the earlier central sensory detection stage of the phonological information is no different from the controls. Our observations are particularly interesting with regard to a study of the children of these two parental groups, where the language-impaired children showed longer P3 latencies than controls in both a tone task and a speech task, whereas there were no differences between the children concerning the N1 component. We propose that deficient late-stage auditory higher order perceptual processing as indexed by the longer P3 latency to speech stimuli observed both in children with specific language-impairment and in their parents may represent a constitutional trait, contributing to the language acquisition difficulties in these children.
This study focused on the role of dichotic listening performance for the identification of reading impaired subtypes. Dichotic listening (DL), using verbal stimuli, has shown to be a valid measure of language lateralization. Usually, lateralization is estimated from the proportion of right ear over left ear accuracy during a free recall test procedure. However, it has been suggested that a more accurate estimate of laterality can be obtained by using a directed attention procedure. A sample of 43 reading disabled children of whom 18 showed signs of impaired language comprehension skills and 25 without language comprehension impairments, were compared to 20 age, and gender, matched controls on dichotic listening performance in both an unbiased free recall task and in a directed attention task using consonant-vowel syllables as dichotic stimuli. A laterality index was calculated for left and right ear stimuli reported during both the free recall condition and the attended ear-scores for the two directed attention conditions. Although both DL procedures yielded significant group differences, with a lower laterality score for the reading disabled compared to the controls, there was no main effect of DL-procedure or group x procedure interaction. Taken alone, DL performance could correctly classify 42% of the reading impaired samples, but together with other measures of executive functions, discriminant function analyses yielded 90.74% accuracy in classifying reading impaired children. The result indicates that DL together with tests of executive functions are valuable tools for assessment of reading impaired subjects.
The CNS infection by HIV-1 in infancy could be present immediately after infection or became manifest later. Microcephalia, mental retardation, pyramidal signs, humor and behavioral disorders and antiretroviral therapy complications are common. This is an observational, sectional and descriptive study about findings on neurological examination of 173 patients in a group of children and adolescents infected and exposed to HIV-1 in perinatal period. Most of them had more than one neurological finding or different diagnosis. The more common findings were: encephalopathy, mental retardation, language delay, pyramidal signs, hyporeflexia. The neurological examination was abnormal in 67% of all patients even in seroreverters. We suggest that this group has a high risk to neurological disease and the development of co-morbidity is directly correlated to clinical deterioration by HIV-1 infection.
'Theory of mind' development is now an important research field in deaf studies. Past research with the classic false belief task has consistently reported a delay in theory of mind development in deaf children born of hearing parents, while performance of second-generation deaf children is more problematic with some contradictory results. The present paper is aimed at testing the metacognitive abilities of deaf children on two tasks: the appearance-reality paradigm designed by Flavell, Flavell and Green (1983) and the classic false belief inference task (Wimmer & Perner, 1983; Hogrefe, Wimmer & Perner, 1986). Twenty-eight second-generation deaf children, 60 deaf children of hearing parents and 36 hearing children, aged 5 to 7, were tested and compared on three appearance-reality and three false belief items. Results show that early exposure to language, be it signed or oral, facilitates performance on the two theory of mind tasks. In addition, native signers equal hearing children in the appearance-reality task while surpassing them on the false belief one. The differences of performance patterns in the two tasks are discussed in terms of linguistic and metarepresentational development.
Event-related brain potentials evoked by tone and speech stimuli were recorded in ten children with specific language impairment and a control group. The patient group showed prolonged P3 latencies in both tasks compared with the controls and smaller P3 amplitude in the speech task. There were no group differences concerning the N1-P2 components. The findings indicate that the children with language impairment showed signs of deficient late-stage auditory perceptual processing whereas the earlier sensory stages as indexed by the N1 were no different from the controls. The results are further discussed within the framework of context updating in working memory.
Southeast Asian immigrants and refugees, in particular the Hmong people of Laos, have settled in large numbers in metropolitan areas of Minnesota. These communities, accustomed to hunting and fishing for food in Laos, now fish in some of the most contaminated waters of Minnesota. Fishing and fish-preparation customs of their homeland emphasize using all fish caught and discarding very little waste. These practices result in a potentially high exposure to PCBs and mercury. Educational outreach efforts to inform this population of the potential health hazards from consuming the fish are hindered by language and cultural barriers. While most Hmong anglers welcome information about contaminants and fishing, the typical press releases and mailings that convey fish advisory information to the public do not reach this community. The Minnesota Department of Health and the Minnesota Department of Natural Resources collaborated to determine the health messages and communication methods that would best meet the needs of these communities. Using the results of interviews and a behavioral survey, the Minnesota Department of Health has tailored fish consumption advisories to meet the unique needs of Southeast Asian anglers. Over the past four years, educational programs involving specialized advisories, translations, signs, a Hmong language video, and workshops have been used to inform Hmong anglers and other Southeast Asians about fish contaminants.
Many neurophysiological hypotheses have focused upon the level of the central nervous system at which abnormal neural function may be present. Although some have argued that the type of language and cognitive defects shown by autistic children almost certainly reflects forebrain dysfunctions, current studies point to the possibility that some autistic children may have dysfunction of neural systems in the brainstem. One interpretation of these findings is that such abnormalities, occurring during a critical phase of early postnatal development, might themselves have acted directly as neuropathological agents, adversely influencing developing forebrain systems. A model for such an event has already been identified in animal research. If this be true, neurobiologists may not necessarily be identifying what is current pathology but may only be seeing a reflection of abnormal neural factors that once were important in development of the syndrome. Such a possibility suggests that investigators should consider extending their current studies to include young normal children as well as children with prototypic signs of abnormal language and interpersonal development.
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Every language, spoken or signed, deploys a large lexicon, made possible by permutation and combination of a small set of linguistic elements. In speech, rapid interleaving of the gestures that form these elements (consonants and vowels) leads to a complex acoustic signal in which the boundaries between elements are lost. However, for the child learning to speak, the initial task is not to recover these elements, but simply to imitate the sound pattern that it hears. Studies of "lipreading" in adults and infants suggest that imitation is mediated by an amodal representation, closely related to the dynamics of articulation, and that a left-hemisphere perceptuo-motor mechanism specialized to make use of this representation develops during the first six months of life. By drawing on this specialized mechanism, the infant learns the recurrent patterns of acoustic structure and articulatory gesture from which linguistic segments must be presumed to emerge.
This paper reports the use of two forms of augmentative and alternative communication (AAC) with young children with Down syndrome: a program using signing (Makaton), and the COMPIC system of computerised pictographs. Children with Down syndrome are frequently reported to have difficulties in the area of language and communication, with relative strengths in visual and perceptual areas. This suggests possible benefits from the use of AAC systems to enhance language development. The paper discusses the use of AAC systems to assist young children with Down syndrome, and reports an experimental study of the use of such systems with an object naming task.
GP, a right-handed woman, without evidence of familial left-handedness, showed clearcut bilateral ideo-motor apraxia and oro-facial apraxia after a vascular lesion of the right hemisphere, encroaching upon the fronto-mesial region. She scored normally in most other cognitive tests, including language, but showed signs of callosal disconnection, left anarchic hand and mild unilateral spatial neglect. This cognitive profile points to the possibility of praxis being localized to the right hemisphere in this right-handed patient. We argue in favour of individual variability of praxis dominance, and maintain that this dominance might be completely right-sided in some subjects. Moreover the anatomical locus of GP's lesion points to the possible role that the frontal lobes (and more specifically the Supplementary Motor Area) play in the genesis of apraxia.