Linguistic production and syntactic comprehension in schizophrenia and bipolar disorder.

OBJECTIVE: To explore linguistic abilities in schizophrenia and bipolar disorder. Specifically, the aims of this study were to: i) investigate microlinguistic (lexicon, morphology, syntax) and macrolinguistic (discourse coherence, pragmatics) dimensions of speech production and ii) evaluate syntactic comprehension skills in both schizophrenia and bipolar disorder. METHOD: Linguistic performance of 30 Italian-speaking patients with schizophrenia, 30 participants with bipolar disorder and 30 healthy controls comparable for age and educational level has been assessed using a story-telling task and a computer-based test of syntactic comprehension. RESULTS: In narrative production, compared with healthy participants, those with schizophrenia had slight problems in speech rate and deficits at both local and global discourse coherence, whereas patients with bipolar disorder showed reduced mean length of utterance. As regards syntactic comprehension, both groups of patients collected more grammatical errors than controls, but they differed with regard to the number and kind of grammatical construction they missed. CONCLUSION: Linguistic deficits have been detected in both groups of patients, being, however, more severe and generalized in schizophrenia than in bipolar disorder. Such results help us in improving our understanding of the potential psychopathological overlapping between these disorders.

Saccadic characteristics in autistic children.

Some studies suggest that individuals with autism present abnormal saccadic eye movements due to an altered strategy for exploration of the surrounding environment. In this study, potential early abnormalities of saccadic movements were explored in 14 male children with autism (5- to 12-year-olds) and in 20 age matched normal males. Only one patient showed clear abnormalities of the "main sequence"; all the other patients, although showing slight changes in saccadic eye movements, did not present classic deficits. Therefore our results did not confirm the presence of saccadic movement alterations in the early stage of autism. Nonetheless, tracts of saccadic initiation failure, continuous changes in saccadic velocity profiles, and instability of fixation were often observed in the autistic population. These findings could be the expression of an early brainstem impairment in autism.

Evaluation of narrative abilities in patients suffering from Duchenne Muscular Dystrophy.

The present work investigated cognitive, linguistic and narrative abilities in a group of children suffering from Duchenne Muscular Dystrophy, an allelic X-linked recessive disorder caused by mutations in the gene encoding dystrophin. The patients showed mildly reduced IQ with lower Verbal than Performance Intelligence Quotient and were mildly affected in visual attention and short-term memory processing. At the linguistic assessment, neither receptive (word comprehension) nor expressive (naming tasks and fluency) lexical abilities were impaired. However, their narratives were qualitatively inferior with respect to those produced by a group of typically developing children. Their speech samples were characterized by the presence of fewer verbs and complete sentences. It is suggested that the reduced production of complete sentences is due to a selective problem in verb argument structure generation. Since the lack of dystrophin is assumed to produce effects on the maturation of the cerebellum, whose involvement has been recently suggested in verb and syntactic processing, these findings may lend indirect support to the hypothesis of a cerebellar-cortical circuit specialized in verb and sentence production.

Development of orofacial praxis of children from 4 to 8 years of age.

Orofacial praxis is the ability to plan and execute movements or sequences of voluntary movements, meaningful or not, using the muscles of the pharyngo-buccofacial system or the orofacial region. An original test was developed, the Orofacial Praxis Test, consisting of 36 gestures, 24 single and 12 complex, elicited through verbal and imitative request. The test was administered to 93 normally developing Italian children ages 4 to 8 yr. to assess development of orofacial praxis. Analysis showed a progressive development of the orofacial praxic ability by type of gesture and examiner's request: (1) the imitation modality is more facilitating than a verbal request modality, especially for children ages 4 or 5 years; (2) a consistent mastery of sequences of gestures and oroverbal movements is in place by age 6 years. The analysis of the orofacial region may be helpful in identifying persistent speech difficulties and developmental coordination disorders.

Language disturbances in a group of participants suffering from Duchenne muscular dystrophy: a pilot study.

Results from several studies suggest that the process of language acquisition may be altered in patients suffering from Duchenne Muscular Dystrophy. In this study, a group of 8 male participants with Duchenne Muscular Dystrophy (M age = 16 yr., SD = 4.7) underwent an extensive neuropsychological and language assessment. They also performed a discourse production task. Results showed mild mental retardation associated with a specific deficit in Verbal rather than Performance IQ. At the linguistic assessment, 7 of 8 participants showed moderate to severe difficulties on oral language processing with particularly impaired morphosyntactic competence.

Opposite musical-manual interference in young vs expert musicians.

Cerebral lateralization for music has been studied through a music-manual interference paradigm (tapping) in a group of young musicians (seven males and seven females) attending the 1st and 3rd intermediate grades of Udine's "J. Tomadini" State Conservatory of Music and in a group of graduated expert musicians or higher course students during the execution of three distinct tasks (singing notes, whistling a melody and singing a melody). A significant superiority of the right hemisphere (greater degree of interference with the left hand) in these tasks has been found in young musicians, while an opposite left hemisphere superiority (greater degree of interference with the right hand) was evident in the expert musicians. Other differences between sexes and tasks were not significant. The modification of hemispheric specialization occurring during academical musical training are discussed in terms of the role of education in the cerebral organization of superior cognitive functions.

Hemispheric asymmetry for the auditory recognition of true and false statements.

A group of right-handed adult subjects (24 males and 24 females) were asked to judge phrases as to their truthfulness of falsehood, by listening to them via earphones either with the right or with the left ear. These phrases, which had been previously recorded by two non-actors (1 male and 1 female) and two actors (1 male and 1 female), were either true or false. The number of correct judgements made by the subjects was significantly higher than the number of wrong judgements. The subjects correctly recognised significantly more true phrases than false ones. Moreover, they better recognised true phrases pronounced by the actors and false phrases pronounced by the non-actors. True phrases pronounced by male speakers and false phrases pronounced by female speakers were better recognised. A left-ear advantage was found in the recognition of true statements.

Long-term neuropsychological deficits after cerebellar infarctions in two young adult twins.

Two young adult dizygotic twins with high schooling suffered two strokes at the ages of 26 and 30 years. On the first occasion, Case 2 suffered a stroke only a few months after Case 1; on the second occasion, Case 1 suffered a second stroke a few months after Case 2. In Case 1, lesions were mainly localized to the left cerebellar hemisphere in both stroke episodes. Case 2 suffered lesions localized to the right cerebellar hemisphere in the first stroke episode, and multiple lesions in both cerebellar hemispheres and the vermis, right pons and left thalamus during the second stroke episode. Seven years after the second stroke, despite full recovery of motor functions, the patients still show mild, yet selective, linguistic deficits (syntactic comprehension deficits, mild agrammatism, reading and writing disorders) without speech disturbances. They also present with selective dysfunctions in visuospatial short-term memory. Language disorders are ascribed to a dysfunction of the cerebellum in Case 1, while in Case 2 a dysfunction of the cerebellum and the thalamus is considered as both structures are part of the so-called 'frontal lobe system', which supports language generation. Visuospatial short-term memory disorders are attributed to an impaired ability to appreciate the organizing structure of the visual task and to poor planning strategies, which are in turn ascribed to cerebellar lesions. The role of the cerebellum in cognitive and linguistic functions is discussed.

Paradoxical selective recovery in a bilingual aphasic following subcortical lesions.

In monolinguals, not only cortical areas but also specific subcortical structures are crucial for language and speech processing. While the role of the left basal ganglia in monolingual aphasia has been defined, its relevance in bilingual and polyglot aphasia is still unknown. Data have now been obtained on a patient who, following an ischaemic lesion not involving cortical structures and mainly confined to the left basal ganglia, showed severe impairments in mother tongue production, with significantly better performance in her hardly spoken second language. This dissociation remained stable for over a year and was observed both in spontaneous speech and in translation tasks. This pattern of linguistic performance, which has never been described in relation to subcortical lesions, suggests that the left basal ganglia play a relevant role in the output of a highly automatized language.

Complete mutism after midbrain periaqueductal gray lesion.

Several neurophysiological studies have highlighted the role of the midbrain periaqueductal gray matter (PAG) in the initiation of vocalization in various animal species, from frogs to primates. With regard to humans, only two cases of complete mutism following a lesion to the PAG have been reported so far. This article describes a new case of a patient (GM) who, following an ischemic lesion to the periaqueductal gray region of the midbrain, presented with complete and irreversible mutism, though her language comprehension functions and her non-verbal expression capacity were preserved. This clinical case provides evidence that in humans the PAG also acts as a link between different vocalization-eliciting external and internal stimuli (which reach the PAG from sensory and emotional structures) and the vocal-motor coordinating mechanisms in the lower brain stem.

Callosal transfer in different subtypes of developmental dyslexia.

Sixteen controls (age 6-13) and 20 native Italian children with developmental dyslexia (age 7-15) received a test of callosal transfer of tactile information. Among the dyslexic children, 7 had a diagnosis of L-type, 7 of P-type and 6 of M-type dyslexia according to Bakker's classification. Both control children and children with dyslexia made a significantly larger number of errors in the crossed localization condition (implying callosal transfer of tactile information) vs. the uncrossed condition. In the same condition, children with dyslexia made a significantly larger number of errors than controls. In the crossed localization condition L-types and M-types made a significantly larger number of errors than P-types and controls, while there was no significant difference in performance between P-types and controls. These findings are discussed in terms of defective callosal transfer or deficient somatosensory representation in children with L- and M-dyslexia.

The bilingual brain: bilingual aphasia.

Since most people in the world know more than one language, bilingual aphasia is an important line of research in clinical and theoretical neurolinguistics. From a clinical and ethical viewpoint, it is no longer acceptable that bilingual aphasics be assessed in only one of the languages they know. Bilingual aphasic patients should receive comparable language tests in all their languages. In the present work, language recovery of 20 bilingual Friulian-Italian aphasics was investigated. Thirteen patients (65%) showed a similar impairment in both languages (parallel recovery), four patients (20%) showed a greater impairment of L2, while three patients (15%) showed a greater impairment of L1. Despite the many hypotheses advanced to account for nonparallel recovery, none of them seems to provide satisfactory explanations. The study of bilingual aphasics with parallel impairment of both languages allows us to verify the hypothesis whereby grammatical disorders in aphasia depend on the specific structure of each language. As far as rehabilitation programs for multilingual aphasics are concerned, several questions have been raised, many of which still need a satisfactory answer.

The bilingual brain: cerebral representation of languages.

The present article deals with theoretical and experimental aspects of language representation in the multilingual brain. Two general approaches were adopted in the study of the bilingual brain. The study of bilingual aphasics allows us to describe dissociations and double dissociations between the different subcomponents of the various languages. Furthermore, symptoms peculiar to bilingual aphasia were reported (pathological mixing and switching and translations disorders) which allowed the correlation of some abilities specific to bilinguals with particular neurofunctional systems. Another approach to the study of the bilingual brain is of the experimental type, such as electrophysiological investigations (electrocorticostimulation during brain surgery and event-related potentials) and functional neuroanatomy studies (positron emission tomography and functional magnetic resonance imaging). Functional neuroanatomy studies investigated the brain representation of languages when processing lexical and syntactic stimuli and short stories. Neurophysiologic and neuroimaging studies evidenced a similar cerebral representation of L1 and L2 lexicons both in early and late bilinguals. The representation of grammatical aspects of languages seems to be different between the two languages if L2 is acquired after the age of 7, with automatic processes and correctness being lower than those of the native language. These results are in line with a greater representation of the two lexicons in the declarative memory systems, whereas morphosyntactic aspects may be organized in different systems according to the acquisition vs learning modality.

Delayed auditory feedback in polyglot simultaneous interpreters.

Twelve polyglot students of simultaneous interpretation and 12 controls (students of the faculty of Medicine) were submitted to a task of verbal fluency under amplified normal auditory feedback (NAF) and under three delayed auditory feedback (DAF) conditions with three different delay intervals (150, 200, and 250 msec). The control group showed a significant reduction in verbal fluency and a significant increase in the number of mistakes in all three DAF conditions. The interpreters' group, however, did not show any significant speech disruption neither in the subjects' mother tongue (L1) nor in their second language (L2) across all DAF conditions. Interpreters' general high verbal fluency along with their ability to pay less attention to their own verbal output make them more resistant to the interfering effects of DAF on speech.

Hemispheric specialization for semantic and syntactic components of language in simultaneous interpreters.

Hemispheric specializations for semantic and syntactic components in Italian (L1) and English (L2) were studied with a dichotic listening test, simulating simultaneous interpretation tasks in 24 right-handed female interpretation students at the Scuola Superiore di Lingue Moderne per Interpreti e Traduttori (SSLM) of the University of Trieste and in 12 right-handed female professional interpreters at the European Communities (EEC). The test involved the recognition of correct translations, translations with semantic errors, and translations with syntactic errors from L1 to L2 and vice versa. As an overall result, both students and interpreters gave significantly more correct answers when sentences in L2 as the target language were sent to the left ear. Students recognized significantly more sentences containing syntactic errors than did professional interpreters, while professional interpreters recognized significantly more sentences with semantic errors than did interpreting students. In regard to hemispheric specialization in interpreting students, no significant asymmetries were revealed in the recognition of semantic and syntactic errors. Professional interpreters showed a significant right-ear superiority in recognizing semantic errors in L1 and a significant left-ear superiority in recognizing semantic errors in L2. In the recognition of syntactic errors, professional interpreters showed significant left-ear superiority for L1 and significant right-ear superiority for L2. The prolonged practice in simultaneous interpreting strategies in EEC professional interpreters may account for some of their peculiar hemispheric specializations for languages revealed by this study.

Cerebral lateralization in simultaneous interpretation.

Cerebral asymmetries for L1 (Italian), L2 (English), and L3 (French, German, Spanish, or Russian) were studied, by using a verbal-manual interference paradigm, in a group of Italian right-handed polyglot female students at the Scuola Superiore di Lingue Moderne per Interpreti e Traduttori (SSLM-School for Interpreters and Translators) of the University of Trieste and in a control group of right-handed monolingual female students at the Medical School of the University of Trieste. In an automatic speech production task no significant cerebral lateralization was found for the mother tongue (L1) either in the interpreting students or in the control group; the interpreting students were not significantly lateralized for the third language (L3), while weak left hemispheric lateralization was shown for L2. A significantly higher degree of verbal-manual interference was found for L1 than for L2 and L3. A significantly higher disruption rate occurred in the meaning-based mode of simultaneous interpretation (from L2 into L1 and vice versa) than in the word-for-word mode (from L2 into L1 and vice versa). No significant overall or hemispheric differences were found during simultaneous interpretation from L1 into L2 or from L2 into L1.

The lateralized linguistic cerebellum: a review and a new hypothesis.

During the past 2 decades the collaboration across disciplines and the methodologic and conceptual advances of contemporary neuroscience have brought about a substantial modification of the traditional view of the cerebellum as a mere coordinator of autonomic and somatic motor functions. Growing insights in the neuroanatomy of the cerebellum and its interconnections, evidence from functional neuroimaging and neurophysiological research, and advancements in clinical and experimental neuropsychology have established the view that the cerebellum participates in a much wider range of functions than conventionally accepted. This increase of insight has brought to the fore that the cerebellum modulates cognitive functioning of at least those parts of the brain to which it is reciprocally connected. This article reviews the recently acknowledged role of the cerebellum in cognition and addresses in more detail experimental and clinical data disclosing the modulatory role of the cerebellum in various non-motor language processes such as lexical retrieval, syntax, and language dynamics. In agreement with the findings indicating a topographical organization of the cerebellar structures involved in language pathology we advance the concept of a "lateralized linguistic cerebellum." In our view crossed cerebral diaschisis processes, reflecting a functional depression of supratentorial language areas due to reduced input via cerebellocortical pathways, might represent the relevant pathomechanism for linguistic deficits associated with cerebellar pathology.

An Italian perspective on learning disabilities.

The authors' experience derives from over 10 years of study of the neuropsychological characteristics of children with learning disabilities (LD) who were referred to a public children's hospital. Some sociocultural and linguistic aspects of children with learning disabilities in Italy, and in particular in the northeastern Friuli-Venetia-Julia region, are described. The role of bilingualism and the type of grapheme-phoneme correspondence in "standard" Italian are discussed in relation to learning disabilities. Legislative aspects, the roles of the school, hospitals, public field services, and private institutes, as well as the concern of parents of children with LD, are alos taken into account. According to the authors, Italy's major deficiencies with respect to the question of learning disabilities are (a) lack of a systematic study of the problem in order to increase general knowledge, (b) insufficient training of teachers and rehabilitators, and (c) inadequate legislation.

Neurolinguistic differentiation of children with subtypes of dyslexia.

A detailed analysis of the types of childhood dyslexia proposed by Boder (1973) and Bakker (1990) revealed characteristic patterns of organization of intellectual functions, of hemispheric specialization, and of reading errors in right-handed children with dyslexia. Children with L-type dyslexia (10 subjects) evidenced a large number of reading errors (e.g., substitutions of nouns and verbs), low scores in verbal short-term memory, and right-ear advantage (REA) in dichotic listening. Children with P-dyslexia (18 subjects) evidenced few reading errors, a short attention span, low performance in visual-motor coordination (WISC-R coding), and an absence of REA in dichotic listening. Children with M-type dyslexia (10 subjects) showed numerous reading errors (e.g., substitution of syllables and words), low performance in visual-motor coordination items (coding), and REA in dichotic listening.

Effects of left basal ganglia lesions on language production.

Three patients with lesions mainly confined to the left basal ganglia were studied with a series of neuropsychological and neurolinguistic tests. Two patients were nonfluent, whereas one presented with fluent spontaneous speech. All of them produced agrammatic sentences and lexical and semantic mistakes. Perserverations and echolalias were two further characteristic disorders of their speech production. The linguistic symptoms observed in these three patients suggest that the left basal ganglia play an important role (a) in regulating arousal and speech initiation, (b) in monitoring the semantic and lexical aspects of language, and (c) in switching from one linguistic element to the following during language production.