British Journal of Disorders of Communication, 26, 383-392 (1991)
© The College of Speech and Language Therapists, London
NOTES AND DISCUSSION SECTION
Following right hemisphere lesions, adults' speech can become copious and inappropriate, with abnormal prosody, and they may be unable to comprehend metaphor or humour. Their symptoms resemble those of children with semantic-pragmatic language disorder, who use fluent, grammatically complex language, but with poor sensitivity to the communicative situation. The hyperlexia found in some of these children reflects an underlying cognitive problem in integrating semantic information with knowledge of the world. Both groups of patients fail to comprehend inferential meaning or to make use of paralinguistic features. It is hypothesised that the disorders of communication and cognition found in semantic-pragmatic language disorder may be linked to right hemisphere dysfunction, but this has yet to be confirmed by research.
A Ia suite de lésions de l'hémisphère droit, la parole d'adultes peut devenir desordonnée et mal à propos, avec une prosodie anormale, et il arrive aussi que ces adultes soient incapables de comprendre les métaphores ou l'humour. Leurs symptômes ressemblent à ceux d'enfants avec des troubles du langage sémanticopragmatique, qui utilisent avec aisance un language complexe grammaticalement, mais avec peu de sensibilité à Ia situation de communication. L'hyperlexie trouvée chez certains de ces enfants reflète un probleme cognitif souslacent lié à l'intégration d'informations sémantiques avec des connaissances du monde. Les deux groupes de patients n'arrivent pas à comprendre les raisonnements inférentiels ou à utiliser des traits paralinguistiques. L'hypothe'se suivante est suggéerée: les troubles de la communication et de Ia cognition trouvés dans les troubles du langage sémanticopragmatique peuvent être liés à un dysfonctionnement de l'hémisphère droit, mais des recherches complémentaires sont nécessaires pour étayer ce point de vue.
Nach Läsionen der rechten Hemisphäre können dIe Sprechäusserungen von Erwachsenen wortreich und unpassend werden, mit abnormer Prosodie. Unter Umständen sind sie unfähig, Metaphoren oder Humor zu verstehen. Ihre Symptome sind denen von Kindern ähnlich, die unter einer semantisch-pragmatische Sprachstörung leiden und eine fliessende, grammatisch komplexe Sprache benutzen, aber mit geringem Feingefühl für die kommunikative Situation. Die Hyperlexie, der man bei manchen dieser Kinder begegnet, lässt ein grundliegendes, kognitives Problem biem Integrieren der semantischen Information mit ihren Kenntnissen der Umwelt erkennen. Bei beiden Patientengruppen fehlt das Verständnis für ableitbare Bedeutung oder die Anwendung paraliguistischer Eigenschaften. Wir stellen die Hypothese vor, dass Störungen der Kommunikation und der Kognition, die man bei der semantisch-pragmatischen Sprachstörungfindet, mit der Dysfunktion in der rechten Hemisphäre verbunden seien, aber dies muss erst noch durch weitere Forschung bestätigt werden.
Key words: semantic-pragmatic disorder, right hemisphere, aphasia.
During the nineteenth century the idea arose that each cerebral hemisphere controlled different functions. Doctors observed patients suffering from sudden loss of speech, which they associated with damage to the left hemisphere. Hughlings Jackson (1865) first drew attention to the contribution of the right hemisphere to linguistic performance, suggesting that it might mediate the less propositional, more automatic aspects of language, such as emotional utterances.
As understanding of both language and brain evolved it became clear that their relationship was a complex one which could not be explained simply in terms of direct localisation. By 1974 Luria was describing linguistic performances as complex functional systems, distributed in widespread cortical constellations or assemblies (Luria, 1974).
The development of linguistics, and its application to clinical work with both developmental and acquired language disorders, have seen a corresponding evolution in the field of neuropsychology. The basic components of linguistic behaviour have been studied, together with the role played in their organisation by various parts of the brain. As the focus of attention has swung in turn to syntax, semantics and then pragmatics, so an interest has developed in the role of the non-dominant right cerebral hemisphere, originally described as the mute, non-verbal side of the brain.
Split-brain research has confirmed that, for most people, the ability to talk is strongly localised in the left hemisphere, but the work of Zaidel (1978) revealed a surprising wealth of language comprehension abilities in the right hemisphere of split-brain patients. It seems that the right hemisphere can show comprehension of certain words, especially object nouns, and research with normal subjects suggests that the extent to which a word's meaning is understood by the right hemisphere depends on how concrete (as opposed to abstract) it is. Whilst the right hemisphere is more literal and concrete in linguistic capacity, it has been suggested that it is better equipped to process abstract rather than concrete images (Myers & West, 1978).
Clinical data also suggest a role for the right hemisphere in the re-acquisition of language, as observed in the right hemisphere recovery of some language functions in aphasia, and the success of melodic intonation therapy (HelmEstabrooks, 1983; Code, 1987). Several writers have suggested a role for the right hemisphere in second language learning in the adult (Lamendella, 1979; Krashen, 1981; Seliger, 1982), claiming that the formulaic and overlearned language typical of the beginning L2 learner is stored or processed in the non-dominant hemisphere. In addition, as Zaidel (1978) observed, selective language deficits do occur following right hemisphere lesions in right-handers. Springer and Deutsch (1989) feel that the question of the nature and extent of right hemisphere involvement in language in the normal brain is one of considerable theoretical and practical significance.
ACQUIRED LESIONS OF THE RIGHT HEMISPHERE
Certainly it is no longer assumed that the right hemisphere is a silent area regarding language (Moscovitch, 1983). But what is known about the functions of this under-rated half of the brain? Hughlings Jackson (1865), in assigning the faculty of expression to the left hemisphere, raised the possibility that perception might be seated in the right hemisphere. Eleven years later Jackson proposed that the right posterior lobe was dominant for visual ideation or thought. Only in the 1930s did data confirm specialised roles for the right hemisphere in visuospatial abilities. It is now well recognised that patients with lesions of the right hemisphere may show profound disturbances in orientation and awareness, resulting from hemispatial inattention or neglect, and from various agnosias, and that the right hemisphere is involved with the analysis of direct information from a patient's own body. But Luria (1973) felt that more important than these gnostic disorders was the disordered perception by the patient of his or her own body and personality, leading to anosognosia: the failure to perceive his or her own defects. Luria quotes a group of patients who used their unimpaired speech to conceal their confusion. He describes them as showing a characteristic over-development of speech: 'verbosity, which bore the character of empty reasoning and which masked their true perceptual defects.'
It is now known that processes are organised differently in the two cerebral hemispheres, with specific processes distributed over larger regions of brain tissue in the right half of the brain than in the left (Semmes, 1968). Disabilities caused by right hemisphere lesions are more subtle and fit less well into established descriptions of brain function. As with left hemisphere lesions, paralysis is often the most debilitating effect, and patients with right hemisphere strokes have not been routinely referred for evaluation of speech and language skills because no such disorders were anticipated. However, once the patient is assessed for a full range of communication skills, rather than simply for skills involving language form, communication problems can be identified in some of these patients. Gardner (1975) described them as having an unchanged command of grammar and of sound structure, but an impaired relationship between their capacity to express themselves in language and their knowledge of the world. Myers observed in 1978 that some right hemisphere lesion patients missed nuances and subtleties: they ignored context and could not fill in what was not present in the words. She described these patients as having few overt language deficits, but having difficulty in communicating. She felt that they had an almost normal ability to impart information, but showed an abnormal ability to take part, or participate, when communicating. Myers later described the speech of these patients as copious and inappropriate, confabulatory, irrelevant, literal and occasionally bizarre. She found that they responded much less appropriately to open-ended questions than to structured ones, and stated that the response of such patients to everyday and automatic conversation may belie a deficit in processing and interpreting more complex external input and in organising, directing and channelling internal information (Myers, 1979).
Other communication deficits have been observed to result from right hemisphere lesions: such patients may speak with a flattened intonation and have difficulty in judging the prosody of others (Heilman, Scholes & Watson, 1975). They may have difficulty with more conceptual aspects of language communication, tending to be overly literal in interpreting words, stories and cartoons. They make literal interpretations of metaphorical statements (Winner & Gardner, 1977; Foldi, Cicone & Gardner, 1983). This is further evidence of the contribution of the right hemisphere to communication. In addition to possessing some comprehension abilities, the non-dominant hemisphere complements left hemisphere language abilities through more subtle communication skills. The perception of emotion, metaphor and humour is vital for successful communication and impairment of such perception will impair the ability to grasp the essence of events, to experience a sense of connectedness with the outside world. It is not surprising that some right hemisphere lesion patients have difficulty utilising and responding to all the extralinguistic or pragmatic aspects of communication, or that the linguistic system itself is inadequate in helping them to derive meaning from on-going events. To understand and accurately communicate experience clearly requires the participation of both sides of the brain.
Bates (1976) felt the right hemisphere's contribution to communication to be most evident in the domain of pragmatics, or the discourse function of language. A study by Hirst, LeDoux and Stein (1984) showed that patients with right hemisphere lesions were able to comprehend literal or conventional meanings, but were unable to determine when this conventional meaning did not apply. Code (1987) reviews studies of other such deficits, involving implicature and inference. Bryan (1988, p.113) states that:
... taken together, the results of work on right hemisphere language processing, particularly at semantic and discourse levels of language, provide evidence for the clinical observations of failure of certain right hemisphere damaged subjects to appreciate humour, connotative aspects of meaning and paralinguistic cues. Their overall impairment in comprehending and using contextual information to derive meaning may partly explain their insensitivity to the pragmatic aspects of communication. They seem unable to extract and isolate key elements, to see the relationships between them, to integrate them into an overall structure and to draw inferences based on these relationships, both in complex linguistic tasks and in discourse.
SEMANTIC-PRAGMATIC LANGUAGE DISORDER
Interesting comparisons can be drawn between these communication deficits observed in some patients with acquired right hemisphere lesions and those described in children with semantic-pragmatic language disorder. Both groups seem to have an underlying difficulty in integrating information, which is reflected in their verbal output. Both groups have relatively intact language form, using fluent, grammatically complex language, but show communication which is impaired by abnormal language content and use. Both groups have poor comprehension and use of non-verbal communication and prosody and both groups perform better on structured tasks than on open-ended ones, making fewer errors in concrete, literal tasks. Both have difficulty in assimilating and using contextual cues. Both tend to lend literal interpretation to figurative language and find difficulty coping with metaphor and humour. Both groups give impulsive answers full of tangential detail and have difficulty in distinguishing the important from the unimportant. Both are reluctant to admit to their communication problems. Both have a reduced sensitivity to the communicative situation and to pragmatic and extralinguistic aspects of communication (Myers, 1978, 1979, 1981; Culloden, Hyde-Wright & Shipman, 1986; Bishop & Rosenbloom, 1987; Bryan, 1988; Bishop & Adams, 1989).
AUTISM AND ASPERGER'S SYNDROME
Dorothy Bishop feels that there may be connections between the social-pragmatic impairments of semantic-pragmatic disorder and those of autism or Asperger's syndrome (Bishop, 1989). Certainly this type of developmental language disorder tends to occur in association with other behavioural and cognitive abnormalities, many of which resemble mild forms of autistic features (Bishop & Rosenbloom, 1987). Abnormal patterns of hemispherical asymmetry have been suspected in autism, and early work hypothesised left hemisphere dysfunction due to the language deficits involved. However, as in semantic-pragmatic disorder, it is delay in language development and abnormal use of language that characterise communication in autism, and the condition can be found in the presence of relatively intact language form. Autistic children show deficits in the areas of prosody, the social use of language and the ability to read emotional expression in language. To the extent to which these functions are lateralised in normal adults, it is the right hemisphere, and not the left, that is involved (Prior & Bradshaw, 1979; Springer & Deutsch, 1989). Fein, Humes, Kaplan, Lucci and Waterhouse (1984) argued that language deficits are not primary in autism, and that many of the characteristic social-affective abnormalities can more plausibly be linked with right hemisphere deficits. Goodman (1989) considered the relative contribution of the two cerebral hemispheres to the features of autism and Asperger's syndrome, noting that language in such individuals is deviant in the domains of pragmatics and prosody. He suggests that innate deficits in the expression and comprehension of non-verbal communication could underpin social/play impairment, and that this 'blindness to the subjective' could correspond, from a cognitive point of view, to lack of a 'theory of mind' (Frith, 1989).
EARLY RIGHT HEMISPHERE DYSFUNCTION
Damage to the right hemisphere which is suffered early in life, or inherited, gives rise to a similar constellation of deficits characterised by emotional and interpersonal difficulties, shyness, visuospatial difficulties, and inadequate paralinguistic communicative abilities. These patients lack eye contact and do not use normal prosody or gesture. They perform worse on aurally presented story recall tests than on paired associative learning tasks (Weintraub & Mesulam, 1983; Voeller, 1986). Weintraub and Mesulam (1983, p.468) feel that:
the integrity of the right hemisphere may be essential for the emergence of interpersonal skills and of what Rymes (1971) has labelled communicative competence'. It is possible that among the population of children who show deficiencies in interpersonal skills there may be some whose symptoms have a neurologic rather than an emotional or social basis.
Another condition around which debate continues about the possible effects of cortical hemisphere function is that of dyslexia. Theories put forward include a lack of cerebral dominance for language, a maturational lag in such dominance, a left hemisphere deficit or interference in left hemisphere functioning by the right hemisphere. Dyslexic children have difficulty in decoding the form of written language, but have a normal ability to extract meaning from text. In contrast, some children from both the semantic-pragmatic disorder group and the autistic group have been observed to show 'hyperlexia', where tests such as the Neale Analysis of Reading Ability (Neale, 1958) reveal their good scores for reading accuracy, accompanied by poor scores for reading comprehension. When autistic and dyslexic children were compared on a large range of oral reading tasks (Frith & Snowling, 1983), it was revealed that the 'barking at print' of the hyperlexic autistic subjects in fact revealed considerable and surprising linguistic competence, but that the hyperlexic group did have a comprehension problem not seen in the dyslexic children. The autistic children had no decoding problem, but failed to use semantic context in the absence of syntactic cues. This failure could not be attributed to a failure of semantic access to individual words, nor to a syntactic failure. This tendency to ignore context (to be field dependent) had been noted in other cognitive tasks (Shah & Frith, 1983) and seemed to be a general characteristic of their behaviour. Their failure in reading for meaning could be seen as related to their failure in making use of redundancy (Hermelin & O'Connor, 1970; Hermelin & Frith, 1971), yet there seemed to be no problem in making use of the context for processing syntax. Frith and Snowling (1983) speculate that this is because purely linguistic ability is intact and problems arise only at the level where extralinguistic factors are concerned. They feel that it may be difficult for autistic children to integrate semantic information derived from single words with their knowledge of the world, derived from previous experience, which they need to be able to do in order to make sense of written (or spoken) material. Tager-Flusberg (1981) demonstrated that it is use of semantic knowledge, not semantic knowledge itself, which underlies the comprehension failure, but it seems that no clear distinction can yet be made between a semantic and a cognitive system failure. Frith and Snowling (1983) guess that the particular problem in comprehension of 'hyperlexic' children lies not within the 'inner lexicon', but within the 'inner encyclopaedia'.
The hypothesis of a failure to make use of redundancy has been suggested to explain many of the handicaps of autistic children (Aurnhammer-Frith, 1969; Hermelin & Frith, 1971). This notion of use of redundancy relates closely to notions of use of context in perception and especially in reading (Frith & Snowling, 1983).
A group of children who showed both hyperlexia and high level semantic difficulties was described by Spence, Fleetwood, Geliot, Wrench, Earles and Searby (1989). These children also had weak spatial concepts, in the absence of body dyspraxia: they showed impulsive behaviour in answering questions, they did not learn from experiences, and they failed to generalise from one situation to another. Spence et al. (1989) felt that the underlying factor in their impulsiveness was the length of time it took them to integrate all available clues. This also caused their general lack of organisation and inflexibility of approach. It is interesting to compare their difficulties with Gardner's description (Gardner, 1975) of patients with right hemisphere lesions who were unable to perform holistic integration of feelings, situational cues and interpersonal relations. The right hemisphere, where information is diffusely represented, specialises in behaviours requiring the integration of information from diverse sources and modalities (Semmes, 1968; Gardner, 1975). It is also instrumental in spatial skills (Benton, 1979). Could right hemisphere dysfunction underlie the problems of the children of Spence et al. (1989)?
The communication difficulties displayed by both some patients with acquired right hemisphere lesions and children with semantic-pragmatic language disorder indicate a failure to understand the processes of inference. These patients can cope with the encoding and decoding aspects of communication, and can extract meaning from the basic sound (or letter) patterns of speech (or writing), but they are unable to deduce the speaker's informative intention so as to bridge the gap between the 'surface' meaning of sentences and the 'deeper' meaning of the thoughts conveyed by those sentences. Sperber and Wilson (1986) proposed the theory of relevance, which has been used to explain the communication difficulties of autism. The central inferential process - which processes the second-order representations described in the theory of mind (Frith, 1989) - is essential for a full appreciation of meaning. It is communication at this sophisticated level, where language and cognition interweave, that is impaired in both the acquired and developmental disorders of communication discussed above. Because the right hemisphere is known to be involved in perception and in integration, could it be the seat of the higher-order cognitive concepts which depend on the existence of second-order representations?
Our knowledge of the contributions of the right cerebral hemisphere to communication is, as yet, incomplete. It is, however, clear from the study of patients with acquired right hemisphere lesions that communication skills can be impaired following right hemisphere damage. Such patients seem to have an abnormal cognitive style which reflects an inability to integrate multimodal perceptual information. This cognitive difficulty reveals itself in their communication, which tends to be fluent and grammatical, but irrelevant, with stereotyped utterances and over-literal interpretations. Their difficulties lie in comprehending the deeper realms of meaning, and in making use of paralinguistic features. This deficit in processing and interpreting more complex information, and in perceiving prosodic features so as to access non-literal meaning, is also seen in the developmental semantic-pragmatic language disorder, and in autism and Asperger's syndrome, where the deceptively competent grasp of language form, with underlying semantic and cognitive deficits, is also demonstrated, in some cases, in the phenomenon of hyperlexia. Gardner's description (Gardner, 1975, p.296) of the abnormal cognitive style of patients with acquired right hemisphere lesions could be a description of semantic-pragmatic disorder:
the patient appears unconcerned about his message; insensitive to his situation, or to the environment; resembling a language machine, a talking computer that decodes literally, gives the most immediate response - insensitive to the ideas behind the questions or to the implications of the questions.
Myers (1984) concludes that this disruption in cognitive style, the inability to use visual imagery, the inability to understand figurative language, the altered affect and the abnormal sense of humour together influence the way patients look at the world, the way they integrate what they see and hear, and the way they respond.
NEED FOR FURTHER RESEARCH
Gardner, Brownell, Wapner and Michelow (1983) warn that their portrait of the linguistic capacities of right hemisphere-damaged subjects is still tentative, and that it is not yet known to what extent specific characteristics apply to all such subjects, or only to those with lesions in a certain site or of a certain size. Nevertheless they feel confident in describing a fairly coherent, if still preliminary, picture of linguistic abnormalities in significantly impaired subjects, who exhibit clear and recurring difficulties when confronted with complex linguistic entities. These difficulties relate to their abilities to conceptualise the unit as a whole, to appreciate its purpose and its form, and to integrate specific elements appropriately within these forms. Many such patients seem insensitive to linguistic context and are unable to cope with the world of fiction, imagination and humour.
Dorothy Bishop (D. V. M. Bishop, 1990, unpublished data from lecture notes) describes how the clinical picture of semantic-pragmatic language disorder changes with age and calls for detailed longitudinal case studies of children with this disorder. Perhaps these observable changes reflect the child's evolving efforts to compensate for abnormal cognitive strategies?
In considering the possibility that one group of developmental language disorders might be linked to right hemisphere dysfunction, it must be admitted that a link between other developmental language disorders and left hemisphere dysfunction has still to be proved! Research could usefully compare the performance of a group of children with semantic-pragmatic language disorder and that of a group of children with expressive language disorder (the groups being paired for age), on a battery of neuropsychological tests designed to assess predominantly right hemisphere governed skills. If the two groups showed significant differences on such a test battery, then this evidence would strengthen the case for links between certain language disorders and unilateral dysfunction, or imbalance, of the cerebral hemispheres.
Caution must always be observed in interpreting clinical observations of patients with acquired disorders so as to explain developmental disorders, but the similarities between the impairments of communication and cognition of these disorders are striking. It will be interesting to see whether such similarities can be confirmed by future research.
AURNHAMMER-FRITH. U. (1969). Emphasis and meaning in recall in normal and autistic children. Language and Speech 12, 29-38.
BATES, K. (1976). Language and Context. London: Academic Press.
BENTON, A. L. (1979). Visuoperceptive, visuospatial and visuoconstructive disorders. In K. M. Heilman & E. Valenstein (Eds), Clinical Neuropsychology. Oxford: Oxford University Press.
BISHOP, D. V. M. (1989). Autism, Asperger's syndrome and semantic-pragmatic disorder: where are the boundaries? British Journal of Disorders of Communication 24, 107-121.
BISHOP, D. V. M. & ADAMS, C. (1989). Conversational characteristics of children with Semantic-pragmatic disorder. II. What features lead to a judgement of inappropriacy? British Journal of Disorders of Communication 24, 231-263.
BISHOP, D. V. M. & ROSENBLOOM, L. (1987). Classification of childhood language disorders. In W. Yule & M. Rutter (Eds), Language Development and Disorders. Clinics in Developmental Medicine (double issue), nos 101-102. London: MacKeith Press.
BRYAN, K. L. (1988). Assessment of language disorders after right hemisphere damage. British Journal of Disorders of Communication 23, 111-125.
CODE, C. (1987). Language, Aphasia and the Right Hemisphere. New York: Wiley.
CULLODEN, M., HYDE-WRIGHT, S. & SHIPMAN, A. (1986). Non-syntactic features of 'semantic-pragmatic' disorders. In: Papers: Advances in Working with Language Disordered Children. ICAN, Allen Graham House, 198 City Road, London ECIV 2PH.
FEIN, D., HUMES, M., KAPLAN, E., LUCCI, D. & WATERHOUSE, L. (1984). The question of left hemisphere dysfunction in infantile autism. Psychological Bulletin 95, 258-281.
FOLDI, N. S., CICONE, M. & GARDNER, H . (1983). Pragmatic aspects of communication in brain damaged patients. In S. J. Segalowitz, (Ed.), Language Functions and Brain Organisation. New York: Academic Press.
FRITH, U. (1989). A new look at language and communication in autism. British Journal of Disorders of Communication 24, 123-150.
FRITH, U. & SNOWLING, M. (1983). Reading for meaning and reading for sound in autistic and dyslexic children. British Journal of Developmental Psychology 1, 329-342.
GARDNER, H. (1975). The Shaaered Mind. New York: Knopf.
GARDNER, H., BROWNELL, H. H., WAPNER, W. & MICHELOW, D. (1983). Missing the point: the role of the right hemisphere in the processing of complex linguistic materials. In E. Perecman (Ed.), Cognitive Processing in the Right Hemisphere. New York: Academic Press.
GOODMAN, R. (1989). Infantile autism: a syndrome of multiple primary deficits? Journal of Autism and Developmental Disorders 19, 409-424.
HEILMAN, K. M., SCHOLES, R. & WATSON, R. T. (1975). Auditory affective agnosia: disturbed comprehenslon of affective speech. Journal of Neurology, Neurosurgery and Psychiatry 38, 69-72.
HELM-ESTABROOKS, N. (1983). Exploiting the right hemisphere for language rehabilitation: melodic intonation therapy. In E. Perecman (Ed.), Cognitive Processing in the Right Hemisphere. New York: Academic Press.
HERMELIN, B. & FRITH, U. (1971). Psychological studies of childhood autism: can autistic children make sense of what they see and hear? Journal of Special Education 5, 107-117.
HERMELIN, B. & O'CONNOR, N. (1970). Psychological Experiments with Autistic Children. Oxford: Pergamon.
HIRST, W., LEDOUX, J. & STEIN, S. (1984). Constraints on the processing of indirect speech acts: evidence from aphasiology. Brain and Language 23, 217-248.
HYMES, D. (1971). Competence and performance in a linguistic theory. In R. Huxley & E. Ingram (Eds), Language Acquisition: Models and Methods. New York: Academic Press.
JACKSON, J. H. (1865). In J. Taylor (Ed.) (1958) Selected Writings of John Hughlings Jackson. New York: Basic Books.
KRASHEN, 5. (1981). Second Language Acquisition and Second Language Learning. Oxford: Penguin.
LAMENDELLA, J. (1979). The neurofunctional basis of pattern practice. TESOL Quanerly 13, 5-19.
LURIA, A. R. (1973). The Working Brain: An Jntroductton to Neuropsychology. Harmondsworth: Penguin.
LURIA, A. R. (1974). Language and brain: towards the basic problems of neurolinguistics. Brain and Language 1, 1-14.
MOSCOVITCH, M. (1983). The linguistic and emotional functions of the normal light hemisphere. In E. Perecman (Ed.), Cognitive Processing in the Right Hemisphere. New York: Academic Press.
MYERS, P. S. (1978). Analysis of right hemisphere communication deficits: implications for speech pathology. In R. H. Brookshire (Ed.), Clinical Aphasiology: Proceedings of the Conference. Minneapolis: BRK Publishers.
MYERS, P. S. (1979). Profiles of communication deficits in patients with right cerebral hemisphere damage. In R. H. Brookshire (Ed.), Clinical Aphasiology: Proceedings of the Conference. Minneapolis: BRK Publishers.
MYERS, P. S. (1981). Treatment of right hemisphere damaged patients: a panel presentation and discussion. In R. H. Brookshire (Ed.), Clinical Aphasiology: Proceedings of the Conference. Minneapolis: BRK Publishers.
MYERS, P.S. (1984). Right hemisphere impairment. In A. L. Holland (Ed.), Language Disorders in Adults. San Diego: College-Hill Press.
MYERS, P.S. & WEST, J. F. (1978). The speech pathologist's role with right hemisphere damaged patients. In R. H. Brookshire (Ed.), Clinical Aphasiology: Proceedings of the Conference. Minneapolis: BRK Publishers.
NEALE, M.D. (1958). Neale Analysis of Reading Ability. Southampton: Macmillan Educational.
PRIOR, M. R. & BRADSHAW, I. L. (1979). Hemispheric functioning in autistic children. Cortex 15, 73-8l.
SELIGER, H. (1982). On the possible role of the right hemisphere in second language acquisition. TESOL Quarterly 16, 307-314.
SEMMES, J. (1968). Hemispheric specialisation, a possible clue to mechanism. Neuropsychologia 6,11-26.
SHAH, A. & FRITH, U. (1983). An islet of ability in autistic children: a research note. Journal of Child Psychology and Psychiatry 24, 613-620.
SPENCE, L., FLEETWOOD, A., GELIOT, J., WRENCH, B., EARLES, L. & SEARBY, C. (1989). A descriptive study of a subgroup of Moor House School children with high level semantic difficulties. In P. Grunwell & A. James (Eds), The Functional Evaluation of Language Disorders. London: Croom-Helm.
SPERBER, D. & WTLSON, D. (1986). Relevance, Communication and Cognition. Oxford: Blackwell.
SPRINGER, S. P. & DEUTSCH, G. (1989). Left Brain, Right Brain. New York: W. H. Freeman & Co.
TAGER-FLUSBERG, H. (1981). Sentence comprehension in autistic children. Applied Psycholinguistics 2, 5-24.
VOELLER, K. K. S. (1986). Right hemisphere deficit syndrome in children. American Journal of Psychiatry 143, l004-1009.
WEINTRAUB, S. & MESULAM, M. (1983). Developmental learning disabilities of the right hemisphere: emotional, interpersonal, and cognitive components. Archives of Neurology 40, 463-468.
WINNER, E. & GARDNER, H. (1977). The comprehension of metaphor in brain-damaged patients. Brain 100, 717-729.
ZAIDEL, E. (1978). Auditory language comprehension in the right hemisphere following cerebral commissurotomy and hemispherectomy: a comparison witb child language and aphasia. In A. Caramazza & E. Zurif (Eds), Language Acquisition and Language Breakdown. Baltimore: Johns Hopkins University Press.
Address correspondence to Mrs J. R. Shields, North Featherstone Speech and Language Unit, North Featherstone School, Gordon St, North Featherstone, Pontefract, W. Yorkshire.
Received June 1990; revised version accepted February 1991.
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