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Biomedical subjects

V Volterra

Publications and source records attributed to V Volterra.

At least 37 records · Page 2Linked to original sources

[Williams syndrome: a window to the development of cognitive and neural processes].

Williams syndrome (SW) is a rare (2-5/100,000) genetic human disorder characterised by a typical facies and mental retardation with a deficit in the visuo-spatial cognitive function and a relative preservation of linguistic abilities. This syndrome also includes morphological anomalies and metabolic-functional impairments, likely deficits in the pattern of brain ontogenesis. Neuropsychological and somatic features of the SW individuals are illustrated, and the correspondent genetic bases, recently identified, are presented. The possible role of NGF (nerve growth factor), a particular neurotrophin involved in the development of brain cholinergic system and the associated behavioural functions, in the aetiology of the typical mental retardation of SW patients, is critically discussed. Prospect of researches, including the identification of potential neurobiological markers and the definition of appropriate cognitive profiles of the SW, in order to precociously diagnose this syndrome, and a more thorough investigation of factors affecting phenotypic expression of this genetically determined pathological condition, are reviewed.

Adolescent↗

Hemispheric specialization for sign language.

Most studies on sign lateralization provide inconclusive results about the role of the two hemispheres in sign language processing, whereas the cases reported in the clinical literature show sign language impairment only following left hemisphere damage, suggesting a similar neural organization to spoken languages. By discriminating different levels of processing, a tachistoscopic study found that in deaf subjects matches of sign language handshapes based on equivalence of meaning are processed faster in the right visual field, thus demonstrating a left hemisphere superiority.

Adolescent↗

Memory abilities in children with Williams syndrome.

Williams syndrome (WS) is a rare genetic condition characterised by intellectual disability, typical facial dysmorphology and several medical anomalies. A specific neuropsychological profile with a dissociation between language (relatively preserved) and visuo-spatial abilities (more seriously impaired) has been hypothesised in these children. Memory abilities of these patients have not been adequately investigated, although they may substantially contribute to better understanding their neuropsychological profile. The present study aimed at investigating verbal and spatial memory in patients with WS (N = 16). Their performance was compared with that of normally developing children on tasks of verbal and spatial span and immediate and delayed recall of verbal and visuo-perceptual materials. Memory abilities of WS children appear to be characterised by defective visuo-spatial memory, both in the short-term and long-term domain, and a dissociation between normal short- but deficient long-term verbal learning. Results are interpreted by supporting the thesis that intellectual disability reflects the defective functioning of a complex system in which some cognitive competencies may be disrupted more than others (Detterman, 1987; Vicari, Albertini and Caltagirone, 1992).

Child↗

Linguistic abilities in Italian children with Williams syndrome.

Recent studies on subjects with Williams syndrome (WS) have revealed a particular facility for language, rarely observed in other mental retarded populations, inspiring much belief in the independence of language from cognition. Lexical and morphosyntactic abilities of 17 Italian WS individuals, between 4.10 and 15.3 years of age, were evaluated both in comprehension and production and compared with those of normally developing Italian children. WS subjects look similar to normal controls in lexical comprehension, but they appear to perform more poorly in grammatical comprehension. Furthermore they look deviant from normals in some morphosyntactic aspects of their production. They perform better than normal controls only with respect to phonological fluency, when semantic aspects are not involved. Our data show very little evidence for a dissociation between language and cognition.

Adolescent↗

Advanced learning technology for a bilingual education of deaf children.

Italian deaf children in elementary and middle school have limited competence in written Italian, which is in part caused by difficulties with lexical and morphosyntactic aspects of the Italian language. This study describes a recently developed interactive multimedia application designed to facilitate deaf children's access to new information and reports the results of an initial experiment conducted with deaf elementary and middle school children. Subjects were twelve deaf children with varying backgrounds and linguistic competencies, ranging in age from 6;6 to 16;1 years. Experimentation was structured in three phases. In the initial phase, children explored the computer environment freely, and in the two subsequent phases, children were presented with activities requiring use of the application to obtain information. Results of a final evaluation indicated that all children were able to use and profit from the application. Findings are discussed in terms of bilingual methods of education for deaf children and their implications for increasing deaf children's competence in written language.

Adolescent↗

Early cognition, communication and language in children with focal brain injury.

The authors report a longitudinal study of the first stages of cognitive, communicative and linguistic development of six Italian-speaking infants with unilateral brain lesions acquired before the point at which language acquisition normally would begin. Substantial variability was observed in the language-cognition profiles displayed by these children. To unify these diverse profiles, the authors propose a 'cognitive infrastructure' or 'threshold' model of early language development, in which the appearance of speech depends on the presence of certain cognitive prerequisites; once those are in place, some degree of dissociation between linguistic and cognitive development can be observed. The contribution of neurological factors to these profiles appears to be complex, suggesting an interaction between lesion site, lesion size and the presence of seizure disorders and/or anticonvulsant drugs.

Age Factors↗

Toward mastery of Italian morphology: a cross-sectional study.

The use of Italian morphology was examined in 34 children ranging in age from 2;6 to 5;0. By the age of 3;6-4;0, high percentages of use in obligatory contexts were seen for a number of grammatical morphemes. Children age 2;6-3;0 showed percentages of use that were somewhat lower than those seen for the older children. In this age range, singular forms were used with higher percentages in obligatory contexts than plural forms, for several different types of grammatical morphemes. Greater control over singular forms in these younger children was corroborated by data from a comprehension task. Even at the younger ages studied, use of grammatical morphemes did not seem influenced by whether phonological cues to agreement were present, or whether the grammatical morphemes were homonymous. Percentages for grammatical morphemes in the form of free-standing morphemes were somewhat lower than percentages for morphemes taking the form of inflections, suggesting that the obligatory nature of inflections in Italian may be a more influential factor than the amount of morphological information contained in a grammatical morpheme.

Child Language↗

Specific language impairment in children: a cross-linguistic study.

A common profile in English-speaking specifically language-impaired children is a moderate deficit across a broad range of linguistic features and a more marked, selective impairment in using bound morphemes and components of the verb system. To gain a clearer understanding of the nature of these more serious problems, we examined the speech of monolingual Italian-speaking as well as English-speaking children with specific language impairment. The evidence suggested that phonological factors contributed significantly to these children's extraordinary problems with particular linguistic features. Contrary to expectations, other marked deficits seemed more related to the opacity of the rules involved and homonymity with other morphemes than to problems with formal grammatical devices in general or components of the verb system in particular.

Child↗

Oral and written language in a case of childhood phonemic deafness.

Neuropsychologic and neurolinguistic studies performed on an 11-year-old Landau-Kleffner boy are reported. At age 3 his language began to deteriorate progressively until complete disappearance. At the same time, the patient developed epileptic seizures. When 6 years old, he was taught to match objects to the corresponding written word, and subsequently he was able to learn reading and writing to such extent that he could attend primary school. BAER and primary cortical auditory responses were normal, whereas late cortical components were grossly retarded and distorted. Phonemic discrimination, identification, and production were absent, and in contrast, lexical-semantic abilities tested through reading and writing were normal. In visual STM tasks, phonologic mediation was absent. The role of phonologic mediation in language acquisition is then hypothesized.

Child↗

First stage of language acquisition through two modalities in deaf and hearing children.

We consider the earliest stages of language acquisition in both vocal and gestural modalities. The basic hypothesis is that there is a kind of equipotentiality between the two modalities and that the choice between the two depends on the linguistic input to which the child is exposed. We set forth the results of studies conducted in deaf and hearing children who acquire as native language the sign language used by deaf persons (gestural modality) and discuss the data on language acquisition in hearing and deaf children exposed to the American Sign Language (ASL) and in deaf children exposed to the Italian Sign Language (LIS). We go on to present the results of work in deaf children exposed to a bimodal Italian input. Against the background of studies in hearing children exposed to spoken Italian only we discuss the role of the gestural modality in the language acquisition of these children from the holophrastic to the diphrastic period. The comparison of sign language acquisition and spoken language acquisition will enable us to assess which aspects may be considered universal and which modality-related.

Adolescent↗

Long-term treatment of chronic schizophrenics with clopenthixol decanoate.

A study was carried out in 68 chronic schizophrenic out-patients to assess the therapeutic effectiveness and tolerance of long-term maintenance treatment with a depot preparation of clopenthixol decanoate. Patients received 200 mg to 600 mg doses by intramuscular injection every 2 to 3 weeks for a mean treatment period of 20.3 months. Clinical symptomatology was assessed at regular intervals using the Brief Psychiatric Rating Scale (BPRS) and any adverse effects were recorded against a standard check-list. The results showed that there was a significant reduction in total and factor composition BPRS scores after treatment in all patients, the improvement becoming generally evident by the sixth month of treatment. Few autonomic and neurological side-effects were reported.

Adult↗