Academic discipline, handedness and immune disorders.

Much debate has surrounded the relative contribution of genetic inheritance and environment to human intelligence. In addition, fetal hormones may influence brain development and affect the qualitative nature of intellectual skills. Geschwind and Behan, Proc. Natn. Acad. Sci. 79, 5097-5100, 1982, have suggested that such hormones may also influence both the development of handedness and the development of the immune system. Members of the faculty of the University of Oxford participated in a survey investigating field of study; handedness and immune disorders. Even amongst right-handers, mathematical academics are significantly more susceptible to rare immune disorders and four times likely as verbal academics, to have suffered from a language related problem in childhood. In contrast to previous suggestions, the incidence of left-handedness is not found to be high amongst pure mathematicians but is significantly higher amongst scientists using mathematical applications.

Surface dyslexia in a child with epilepsy.

N.G. is a 13-year-old boy with surface dyslexia. He is significantly better at reading aloud words with regular spelling-to-sound patterns than those with irregular. He displays homophone confusion. N.G.'s case is particularly pure since he makes no invalid/visual errors. All errors are strictly rule-governed. Even long unfamiliar words are read with good accuracy. Both aural and reading comprehension are severely impaired. It is concluded that by age 13, an isolated and efficient system of phonic reading may develop which is based on grapheme-phoneme conversion or on graphemic chunks converted to phonological segments.

Patterns of spatial functioning in Turner's syndrome.

This paper presents results from a study of task performance on a variety of spatial tasks in 9-11 year-old children with Turner's Syndrome (T.S.), divided into those with genotype 45XO and those with Mixed genotypes, including isochromosomes of X and mosaicism. There was a significant overall effect of group reflecting impaired spatial cognition in T.S. with greater decrement in the 45XO group. Further investigation of the significant group by task interaction indicated that the group effects appeared on a visuo-perceptual task and on three visuo-constructional tasks but that there were no specific deficits in the T.S. groups on visuo-spatial or tactile-spatial tasks. In T.S., visuo-perceptual and visuo-constructive sub-systems of spatial skill may be more vulnerable than other components of spatial cognition, to the neuro-biological influences which contribute to the disorder. Such dissociation supports theories of modularity in the development of spatial skill. The spatial tasks which create difficulty overlap only partially with those for which there are sex differences amongst normal children and do not represent a simple exaggeration of normal male-female differences.

Reading skills in children with Turner's syndrome: an analysis of hyperplexia.

Most neuropsychological studies of cases of chromosomal abnormalities report associations with disorders or disabilities. Studies of Turner's Syndrome (TS), in which their is functional absence of the information carried on the short arm of the second X chromosome, have emphasised disorders of spatial skill and potential abnormality of the parietal lobes or right hemisphere. In contrast, language skills have received little investigation despite suggestions by Shaffer (1962) of considerable verbal skill. This paper reports on an analysis of reading skill, in girls with TS. The girls with TS attained reading levels higher than those predicted on the basis of their age and intelligence. Moreover, they attained significantly higher reading levels than controls. Unlike many previous studies of hyperlexia, reading comprehension was also better than controls. The hyperlexia of the girls with TS was characterised by strength in both lexical reading systems, as assessed by the ability to read irregular words, and strength in alphabetical or phonological reading skills, as assessed by the ability to read long unfamiliar regular words. Hyperlexia need not therefore co-occur with comprehension difficulties nor need it reflect strength in only part of the reading system. In TS it appears to represent a genuine hyperdevelopment of a skill. The strength of reading skill counterbalances the spatial difficulties of a comparable sample of girls with TS (Temple and Carney, 1995), and with other verbal skills may potentially be exploited in remedial enterprises.

Phonemic discrimination in callosal agenesis.

Children with callosal agenesis have congenital absence of the corpus callosum. Previous analyses of these subjects have shown that they have significant difficulty on rhyming tasks and tasks of explicit sound organisation. This study investigated whether such difficulties were also manifested on simpler tasks requiring the discrimination and repetition of similar sounding linguistic material. None of the acallosal children tested performed at a normal level across tasks. This suggests a possible impairment in the initial registration or analysis of auditory material and possible bases for this deficit are discussed. In cases of callosal agenesis in which impairments in auditory discrimination are more severe there may be a more profound impact upon language development.

New approaches to the developmental dyslexias.

Although Hinshelwood (10-15), at the turn of the century, was interested in both analysis of individual cases and comparisons between acquired and developmental dyslexia, the most widespread approach to the developmental dyslexias has been the investigation of large groups of dyslexics in comparison to normal readers on a variety of tests. These studies ignore the heterogeneity of the disorder. In contrast, progress has been made in the investigation of acquired disorders of reading by conducting individual psycholinguistic analyses of reading difficulties and utilizing input from cognitive psychology to construct explanatory models and theories. Two of the disorders described and elucidated by this approach are acquired surface dyslexia, in which there is an impairment in whole word recognition and overreliance on sounding out words to obtain their pronunciation and meaning, and acquired phonological dyslexia, in which whole word recognition is good but sounding out of words and nonwords is poor. This approach has recently been used with cases of developmental dyslexia. This chapter compares and contrasts the pattern of performance of different dyslexic children when investigated in this way. Two of the children described are developmental phonological dyslexics; one is a developmental surface dyslexic. The developmental phonological dyslexics are poorer at reading words than non-words; the developmental surface dyslexic performs equally well on both. The developmental surface dyslexic is significantly influenced by spelling-to-sound regularity; the developmental phonological dyslexics are unaffected by this linguistic dimension. The developmental surface dyslexic makes more neologistic responses than the developmental phonological dyslexics, and also makes more valid errors. The developmental phonological dyslexics make derivational, pseudoderivational, and visuosemantic errors. Both groups make visual errors. The developmental phonological dyslexics are significantly impaired when stimuli are presented in a way that prohibits global analysis; the developmental surface dyslexic is unaffected by this manipulation. The developmental surface dyslexic makes homophone confusions, but these are not made by the developmental phonological dyslexics. (ABSTRACT TRUNCATED AT 400 WORDS)

Lateralisation of language function in young adults born very preterm.

OBJECTIVE: To explore, using functional magnetic resonance imaging (MRI), the functional organisation of phonological processing in young adults born very preterm. SUBJECTS: Six right handed male subjects with radiological evidence of thinning of the corpus callosum were selected from a cohort of very preterm subjects. Six normal right handed male volunteers acted as controls. METHOD: Blood oxygenation level dependent contrast echoplanar images were acquired over five minutes at 1.5 T while subjects performed the tasks. During the ON condition, subjects were visually presented with pairs of non-words and asked to press a key when a pair of words rhymed (phonological processing). This task alternated with the OFF condition, which required subjects to make letter case judgments of visually presented pairs of consonant letter strings (orthographic processing). Generic brain activation maps were constructed from individual images by sinusoidal regression and non-parametric testing. Between group differences in the mean power of experimental response were identified on a voxel wise basis by analysis of variance. RESULTS: Compared with controls, the subjects with thinning of the corpus callosum showed significantly reduced power of response in the left hemisphere, including the peristriate cortex and the cerebellum, as well as in the right parietal association area. Significantly increased power of response was observed in the right precentral gyrus and the right supplementary motor area. CONCLUSIONS: The data show evidence of increased frontal and decreased occipital activation in male subjects with neurodevelopmental thinning of the corpus callosum, which may be due to the operation of developmental compensatory mechanisms.

Red is read but eye is blue: a case study of developmental dyslexia and follow-up report.

Recently, analogies have been drawn between the developmental and acquired dyslexias, but there has been no unequivocal report of developmental deep dyslexia. The case is reported here of a 9-year-old child whose reading performance resembles deep dyslexia in several ways. The incidence of errors with a semantic component is shown to be significantly above chance. The pattern of errors is discussed in relation to recent data on error patterns in normal beginning readers. Text reading, spelling, naming, and repetition are described. In contrast to previous case reports, follow-up data are presented which chart the qualitative changes in performance over time despite relatively little quantitative change. The child described has several specific handicaps. Developmental deep dyslexia may not be a prevalent subtype because the multiple impairments necessary to produce the disorder seldom co-occur and may tend to preclude reading development altogether.

A further study of language function in callosal agenesis.

A subset of the tests of language ability administered by M. Dennis (1981, Brain and Language, 12, 33-53) was given to two adult acallosal patients. One of the patients studied showed widespread language deficits not restricted to the syntactic-pragmatic core as in Dennis' patient. The other showed a very specific deficit which does not encompass syntactic-pragmatic skills. The data does not support the view that the corpus callosum is necessary for the normal development of specific language functions.

Ten pen men: rhyming skills in two children with callosal agenesis.

Cases of callosal agenesis provide unique opportunities to investigate the normal role of the corpus callosum in the development of cognitive functions, including language. The only language impairment which has been consistently observed in three acallosal patients is on the retrieval of words from rhyming cues. Two new cases of callosal agenesis in children of normal intelligence are presented. Their performance on a variety of rhyming tasks involving both production and recognition of rhyme is reported. Both children display deficits and possible explanations are discussed.

Reading in callosal agenesis.

It has been suggested that deficits in explicit phonological processing are causal in developmental dyslexia. Deficits in such skills have been reported in developmental phonological dyslexia, though not in developmental surface dyslexia. The reading performance of two children with callosal agenesis, who have been previously shown to have impairments on rhyming tasks, are reported. Neither child is dyslexic in the traditional sense, since word reading levels are appropriate for age. However, both children have impaired development of the phonological reading route despite normal lexical skills. The pattern of their reading is therefore comparable to developmental phonological dyslexia. Problems in explicit phonological processing may be causal in the failure to establish an efficient phonological reading route but this is insufficient to create difficulty with word recognition itself. The corpus callosum may be essential for the normal development of a phonological reading route.

A case study of developmental phonological dyslexia.

H.M. is a 17-year-old girl of at least average intelligence and with an above-average oral vocabulary. She is impaired at non-word reading in comparison to word reading. She is incapable of reading any long nonsense words or long unusual regular words correctly. Many of her non-word reading responses are lexicalizations. She reads non-words homophonic with real words better than she reads non-words that are not homophonic with real words. Her reading age is 10 years 11 months. A large proportion of her reading errors are derivational or visual paralexias. She makes no semantic errors or errors of regularization and few neologistic responses. H.M. is not influenced by the dimensions of spelling-to-sound regularity and word length. There is no effect of word class on single-word reading although a function word deficit is present when continuous text is read aloud. H.M. is impaired at word reading when the stimulus items are distorted in a manner that reduces the potential for global perception. H.M.'s spelling errors are primarily phonological, though more complex errors are made than those characteristic of surface agraphics. All of these features are consistent with reported cases of acquired phonological dyslexia. H.M. may be confidently regarded as a developmental phonological dyslexic.

Developmental dyslexia and dysgraphia persistence in middle age.

J.R. is a middle-aged man whose developmental dyslexia and dysgraphia have persisted in a problematic fashion for the 30 years since he left school. He is a phonological dyslexic. Whereas surface dyslexics operate on reading units that are too small, Mr. R operates on units that are too large. Spelling exhibits both regularity and lexicality effects. These seemingly contradictory results are consistent with a two-route model of spelling in which each route is functioning with approximately 50% efficiency. Performance on paralinguistic rhyming tasks is poor and shows no recovery in comparison to younger developmental phonological dyslexics. Difficulties with higher-order sound segmentation, analysis, or organization may underly the lifelong literacy problems.

Managing physical assault in a healthcare setting.

Violence is escalating in society, and it is increasingly recognized that caregivers in the healthcare setting are at risk. Workers who have had appropriate self-defense training are attacked less often, and they incur less serious injuries when they are attacked. Healthcare workers may exert reasonable force in self-defense, although the standard response to possible violence should be to prevent it or to talk one's way out of it, if possible. In this article, the author describes some basic self-defense techniques that healthcare workers can use if necessary.

Cognitive neuropsychology and its application to children.

Cognitive neuropsychology has been used successfully in the analysis of adult neuropsychological disorders in both verbal and nonverbal domains. When applied to children, it aims to construct models on the basis of functional lesions manifest within developing systems and provides a theoretical framework within which patterns of intact and deficient skills can be charted over time. These patterns constrain possible underlying models. In highlighting potential individual differences in the acquisition of skills and indicating intact skills within subjects, cognitive neuropsychology may also enable a precise description of the locus of difficulty and potential circumventory routes for remediation around it. The theoretical assumptions of cognitive neuropsychology and issues relevant to its methodology are discussed, including the terminology and principles of modularity, the significance of individual differences and the use of case studies, the dynamics of developing systems, current views on plasticity, and distinctions between developmental and acquired disorders. The application of cognitive neuropsychology to children is discussed in relation to three cognitive areas: face recognition disorders, language disorders and arithmetical disorders. These illustrate the similarities that there are between many developmental cognitive neuropsychological disorders and those seen in adults following brain injury. Models derived from studies of adults are helpful in enabling understanding of both face recognition disorders and arithmetical disorders in childhood. Within language systems, a variety of different types of disorder are evident, which not only relate to receptive and productive difficulties but differentially affect the core components of the language system. All of the disorders discussed illustrate the limitations of functional plasticity in development. In each case, there is not a generalised deficit resulting from degradation of capabilities independent of task requirements. Rather, there are focal and selective disorders which affect subcomponents of cognitive systems. In some cases, genetic factors may constrain compensatory mechanisms.

Anomia for animals in a child.

The occurrence of anomia which particularly affected the category of animals is described in a 12-year-old boy. This difficulty cannot be accounted for by frequency or familiarity and is unaffected by whether the stimulus is a line drawing, photograph or model. The deficit does not represent development lag, as normal children of the same naming age differ qualitatively. The results, which include a one year follow-up, are discussed in relation to unitary versus multiple semantic systems. The disorder includes a disturbance of memory arising during the developmental period. It is suggested that items which are involved in daily actions can be more easily remembered than those which are identified by sensory features alone, and that the preserved learning of motor skills in acquired amnesia may be of relevance.

Reading with partial phonology: developmental phonological dyslexia.

Recent psycholinguistic investigations have advanced our understanding of the acquired dyslexias. Developmental analogues have been described to some of these disorders. A new case of developmental phonological dyslexia is described here. A.H. is an intelligent 10-year-old boy with no neurological abnormality. Reading and spelling are below age level. A.H. is poorer at reading words than nonwords. The majority of his errors are paralexias: visual, derivations, or visuosemantic. Spelling-to-sound regularity does not affect the ability to read aloud. A.H.'s reading performance is significantly impaired when words are presented typed in reverse order, thereby prohibiting global strategies. Spelling of nonwords is no better than reading of nonwords. Only one-fifth of spelling errors are phonologically valid. A.H. has imperfect development of both the phonological route to reading and the phonological route to spelling.

Intellectual functioning of children with Turner syndrome: a comparison of behavioural phenotypes.

This study reports the results of 19 girls with Turner syndrome (TS), aged between nine and 12 years, in relation to intellectual profile and genotypic variation. The results were consistent with the notion that the behavioural phenotype of mixed TS involving predominantly mosaic karyotypes is less deviant from the normal pattern than that of pure 45XO. The results for the pure TS girls were consistent with an exaggeration of a normal sex difference, but for mixed TS girls this effect was task-dependent. There was no evidence of generalised deficiency or immaturity, and the task-specific effects support modularity in the development of components of cognitive skill and spatial ability. They also support a specific overall intellectual profile in TS, but with considerable inter-individual variation in its expression.

Neonatal seizures: long-term outcome and cognitive development among 'normal' survivors.

The authors report the long-term outcome and cognitive development in the late-teenage years of 'normal' survivors of neonatal seizures. The outcome of the children was good, and normal in that they had attended normal schools and had normal overall intelligence test scores as adults. However, all of the sample displayed abnormal neuropsychological development in terms of intelligence test profile and subtest scatter, or development of spelling, or development of memory. This was independent of social and behavioural difficulties, which may also be increased. Neonatal seizures may be indicative of a subtle neurodevelopmental vulnerability which may manifest later in life as specific learning difficulties or poor social adjustment.