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.

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.

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.

Greater syntactic impairments in native language in bilingual Parkinsonian patients.

OBJECTIVE: To investigate the presence of syntactic impairments in native language in Parkinson's disease. METHODS: Twelve bilingual patients, with Friulian as their first language (L1) and Italian as their second (L2), with Parkinson's disease and 12 normal controls matched for age, sex, and years of schooling, were studied on three syntactic tasks. RESULTS: Patients with Parkinson's disease showed a greater impairment of L1 than L2. CONCLUSIONS: These findings provide evidence of greater basal ganglia involvement in the acquisition and further processing of grammar in L1 v L2 possibly due to a major involvement of procedural memory in representing L1 grammar.

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.

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.

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 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.

Pathological switching between languages after frontal lesions in a bilingual patient.

Cerebral lesions may alter the capability of bilingual subjects to separate their languages and use each language in appropriate contexts. Patients who show pathological mixing intermingle different languages within a single utterance. By contrast, patients affected by pathological switching alternate their languages across different utterances (a self contained segment of speech that stands on its own and conveys its own independent meaning). Cases of pathological mixing have been reported after lesions to the left temporoparietal lobe. By contrast, information on the neural loci involved in pathological switching is scarce. In this paper a description is given for the first time of a patient with a lesion to the left anterior cingulate and to the frontal lobe-also marginally involving the right anterior cingulate area-who presented with pathological switching between languages in the absence of any other linguistic impairment. Thus, unlike pathological mixing that typically occurs in bilingual aphasia, pathological switching may be independent of language mechanisms.

Effects of praying and a working memory task in participants trained in meditation and controls on the occurrence of spontaneous thoughts.

So-called "intrusive thoughts" appear independently from external stimuli and are the cause of severe disturbances in depressed patients. Following Baddeley's 1986 discoveries regarding "articulatory suppression," we investigated the influence of praying and of a working memory task on the number of spontaneous thoughts reported by 20 subjects compared to the control (quiet) state. Two groups of subjects were tested: those trained in meditation and controls. Significant reduction in simultaneous thought arousal was obtained during both the working memory task and the recitation of prayer. In all three experimental conditions, meditation practitioners reported significantly fewer spontaneous thoughts.

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.

Speaking speed effects on delayed auditory feedback disruption of speech fluency.

24 Italian medical students performed a task of verbal fluency. 12 students (the control group) receiving Normal Auditory Feedback and 12 students receiving Delayed Auditory Feedback (delay of 200 msec.) performed six trials in six different experimental settings: normal or increased speaking rate, and, for each condition, once with bilateral input of the auditory feedback, once to the right ear, and once to the left ear. At the normal speaking rate, the disruptive effect of delayed feedback was confirmed. As the speaking rate increased, the total number of errors increased within the control group but decreased within the group given delayed feedback, although the total number of errors was always greater for the latter. In addition, speech was more disrupted when the auditory input was returned to the right ear (left hemisphere) for all the different conditions: Normal and Delayed Auditory Feedback, normal and increased speaking rate. In particular, the left hemisphere was less resistant to the disruptive effect of the delayed feedback than the right hemisphere. From these results, we suggest that, when speaking more quickly, one uses more central mechanisms of movement programming (cortical-cerebellum-thalamus-cortical, cortical-corpus striatum-thalamus-cortical, and cortical-thalamus-cortical circuits), or attentional control (cortico-reticular-cortical circuits) than peripheral mechanisms (tactile, proprioceptive, and acoustic circuits). This may explain the decreased disruptive influence of delayed auditory feedback on speed, fluency, and quality at increased speaking rates. Hemispheric specialization processes, however, may explain the more pronounced susceptibility of the left hemisphere or the less pronounced susceptibility of the right hemisphere during the delayed feedback condition. In fact, the former processes phonemic, grammatical, and lexical features of words whilst the latter is competent in using metaphors and prosody in controlling the emotional aspects of language. Moreover, the right hemisphere is more active on attentional tasks.

Encoding and recall of parsed stories in hypnosis.

To define the relationship between aspects of memory concerning encoding and recall of short texts and hypnosis, standardized stories were narrated to 12 subjects, both during ordinary state of consciousness and after hypnotic induction by means of the Stanford Hypnotic Susceptibility Scale (Form C). The narrative material used as a stimulus was based on several stories taken from popular oral tradition, previously analyzed according to the classic criteria proposed by Rumelhart in 1975 and Mandler and Johnson in 1977. The subjects' memory performance during both experimental conditions was tape-recorded and compared with the analysis of the original stories (Terminal Nodes) as well as with the higher linguistic structures of the scheme (Basic Nodes), according to Rumelhart's typology. During hypnosis, the subjects recalled significantly fewer narrative elements at both levels of analysis (Terminal Nodes and Basic Nodes). We conclude that hypnosis does not enhance recent memory.

Thalamic amnesia following venous infarction: evidence from a single case study.

The present paper describes the case of a right-handed Italian-English bilingual male patient suffering from amnesia following a bilateral thalamic lesion due to venous infarction. Within a few months from the onset, the lesion gradually shrank and was finally confined to the left thalamus only, in particular to the antero-medial portion and the pulvinar. The mammillary bodies and the cortical areas of both hemispheres were spared. After the regression of a series of generalized cognitive deficits implying slow psychic activity confusion, and spatial and temporal disorientation, the patient presented a persistent amnesic syndrome with mild language disorders, both in Italian and in English. Major disorders of memory included a dissociation between verbal memory, which was severely impaired, and spatial memory, which was largely preserved.

Neurolinguistic and follow-up study of an unusual pattern of recovery from bilingual subcortical aphasia.

We report on the neuropsychological and neurolinguistic features of a bilingual patient, E.M., who presented with an uncommon pattern of aphasic deficit consequent to subcortical lesions mainly involving the left basal ganglia. Not only are reports of bilingual subcortical aphasia rare, but E.M.'s deficit is particularly uncommon for it concerns the most used mother tongue (Venetian) much more than a less practiced second language (standard Italian). In this patient, the linguistic deficit in mother tongue production has been observed in spontaneous speech and in cross language translation tasks, where an asymmetrical paradoxical performance has been revealed. Indeed, unlike neurologically intact subjects, E.M. has more difficulties when translating into her mother tongue than into her second language. Although E.M.'s mother tongue is prevalently an oral language, the asymmetrical translation pattern is similar in written and oral translation tasks, thus ruling out the possibility that the deficit simply reflects differences between written and oral language codes. Finally, another remarkable feature of E.M.'s impairment is its stability over almost 5 years from the stroke. We propose that this unusual type of recovery in E.M. is related to the higher degree of automatization of the first language with respect to the second one. This proposal fits with the role of basal ganglia in automatized motor and cognitive performance.

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.

Effects of hypnosis on the fundamental frequency of voice in different emotional imitations.

The modifications of human vocal fundamental frequency (fa) were studied in six emotional imitations of a sequence during normal and hypnotic conditions. In hypnosis the fundamental frequency was significantly lower than in the normal condition; in particular, in this altered state of consciousness two emotional imitations (angry and crying conditions) were significantly different with respect to the normal condition.