Search PubMed⌕ Search

Biomedical subjects

D V Bishop

Publications and source records attributed to D V Bishop.

At least 37 records · Page 2Linked to original sources
PubMed1998

Quantifying hand preference using a behavioural continuum.

Bishop, Ross, Daniels, and Bright (1996) proposed a novel approach to quantifying hand preference (QHP) using a single behavioural measure. The extent to which individuals used their dominant hand to reach across the midline to pick up cards discriminated subgroups of right-handers, similarly categorised by their scores on the Edinburgh Handedness Inventory. This study aimed to investigate whether (1) the QHP approach was able to differentiate subgroups within the left-handed as well as right-handed populations, (2) left-handers behave like mirror-image right-handers, and (3) if interacting with the environment in extrapersonal space is influenced by the level of fine motor skill demanded by the task. Results support the use of the QHP to discriminate subgroups of both left- and right-handers, particularly when the task demands very fine motor skill or very little. Left-handers behaved as mirror-images of the right-handers except when performing the unskilled motor task in which they showed greater readiness to use the nonpreferred hand. These results suggest that interaction with the environment in extrapersonal space may be a key factor contributing to manual dominance and that the lateralisation of fine motor skill interacts with this attentional bias.

Journal Article↗
PubMed1998

A reaching test reveals weak hand preference in specific language impairment and developmental co-ordination disorder.

A reaching test for quantifying hand preference (QHP task) was given to 7- to 11- year-old children with specific language impairment (SLI) or developmental coordination disorder (DCD). The performance of these clinical children was compared to both an age-matched and younger control group. The four groups did not differ in terms of preferred writing hand or preference on a handedness questionnaire. The QHP measure discriminated the clinical and younger control groups from the age-matched controls, but not from each other. Right-handed children with SLI, DCD, and the younger controls reached predominantly with the right hand to spatial positions located to the right of their body's midline and with the left hand to positions situated to its left. Right-handers in the age-matched control group showed a significantly greater tendency to use their right hand to reach to all spatial positions. The increased tendency of the children with SLI to use the non-preferred hand was particularly striking because it was seen both in those with and without recognised motor difficulties. The QHP task appears to be a sensitive, but non-specific, indicator of developmental disorders.

Journal Article↗
PubMed1998

Development of the Children's Communication Checklist (CCC): a method for assessing qualitative aspects of communicative impairment in children.

The Children's Communication Checklist (CCC) was developed to assess aspects of communicative impairment that are not adequately evaluated by contemporary standardised language tests. These are predominantly pragmatic abnormalities seen in social communication, although other qualitative aspects of speech and language were also included. Some items covering social relationships and restricted interests were incorporated, so that the relationship between pragmatic difficulties and other characteristics of pervasive developmental disorders could be explored. Checklist ratings were obtained for 76 children aged 7 to 9 years, all of whom had received special education for language impairment. In 71 cases, 2 raters (usually a teacher and speech-language therapist) independently completed the checklist, making it possible to establish inter-rater reliability. From an initial pool of 93 items, 70 items, grouped into 9 scales, were retained. Five of the subscales were concerned with pragmatic aspects of communication. A composite pragmatic impairment scale formed from these subscales had inter-rater reliability and internal consistency of around .80. This composite discriminated between children with a school diagnosis of semantic-pragmatic disorder and those with other types of specific language impairment (SLI). The majority of children with pragmatic language impairments did not have any evidence of restricted interests or significant difficulties in the domains of social relationships.

Adolescent↗
PubMed1997

Evidence from Turner's syndrome of an imprinted X-linked locus affecting cognitive function.

Turner's syndrome is a sporadic disorder of human females in which all or part of one X chromosome is deleted. Intelligence is usually normal but social adjustment problems are common. Here we report a study of 80 females with Turner's syndrome and a single X chromosome, in 55 of which the X was maternally derived (45,X[m]) and in 25 it was of paternal origin (45,X[p]). Members of the 45,X[p] group were significantly better adjusted, with superior verbal and higher-order executive function skills, which mediate social interactions. Our observations suggest that there is a genetic locus for social cognition, which is imprinted and is not expressed from the maternally derived X chromosome. Neuropsychological and molecular investigations of eight females with partial deletions of the short arm of the X chromosome indicate that the putative imprinted locus escapes X-inactivation, and probably lies on Xq or close to the centromere on Xp. If expressed only from the X chromosome of paternal origin, the existence of this locus could explain why 46,XY males (whose single X chromosome is maternal) are more vulnerable to developmental disorders of language and social cognition, such as autism, than are 46,XX females.

Adolescent↗
PubMed1997

Pre- and perinatal hazards and family background in children with specific language impairments: a study of twins.

A clinical group composed of 84 twin pairs where one or both twins met stringent psychometric criteria for specific speech-language impairment was compared with 36 twin pairs with no history of speech-language difficulties. Twins with speech-language impairment tended to have more siblings than control twins and were significantly more likely to have an affected parent. Groups were closely similar in terms of length of gestation and mother's antenatal condition, except that maternal toxemia was unusually frequent in the clinical group. Children from the two groups did not differ in terms of Apgar scores or on a composite measure of perinatal hazards. Within the clinical group, MZ pairs with substantial differences in neonatal status did not differ in language outcome. It is suggested that if an association with toxemia can be replicated, this might reflect a common genetic basis for immune disorders and developmental language delay. Perinatal hazard was unrelated to subtype of speech-language impairment.

Child↗
PubMed1997

Cognitive neuropsychology and developmental disorders: uncomfortable bedfellows.

Cognitive neuropsychology provides a theoretical framework and methods that can be of value in the study of developmental disorders, but the "dissociation" logic at the centre of this approach is not well suited to the developmental context. This is illustrated with examples from specific language impairment. Within the developing language system there is ample evidence for interaction between levels of representation, with modularity emerging in the course of development. This means that one typically is seeking to explain a complex pattern of associated impairments, rather than highly selective deficits. For instance, a selective impairment in auditory processing can have repercussions through the language system and may lead to distinctive syntactic deficits that are seen in written as well as spoken language. Changes in the nature of representations and in the relationships between components of a developing system mean that cross-sectional data at a single point in development may be misleading indicators of the primary deficit. Furthermore, traditional cognitive neuropsychology places a disproportionate emphasis on representational (competence) deficits, with processing (performance) deficits being relatively neglected. Methods for distinguishing these two kinds of impairment are discussed, as well as other approaches for elucidating the underlying nature of developmental disorders.

Child↗
PubMed1996

Nonword repetition as a behavioural marker for inherited language impairment: evidence from a twin study.

The Children's Nonword Repetition Test (CNRep) was given 39 children with persistent language impairment (LI), 13 with a history of having received speech-language therapy (resolved LI), and 79 controls, all aged from 7 to 9 years. The children with LI were twins who had participated in a previous genetic study. Children with resolved LI, as well as those with persistent LI, were significantly impaired on the CNRep. Comparisons of MZ and DZ twins indicated significant heritability of a CNRep deficit. It is concluded that CNRep provides a marker of the phenotype of heritable forms of developmental language impairment.

Child↗
PubMed1996

The measurement of hand preference: a validation study comparing three groups of right-handers.

Three groups of right-handers were identified using the Edinburgh Handedness Inventory. Exclusive strong right-handers (Rs: N = 18) reported that they always used the right hand for eight or more of the 10 activities, and usually used the right hand for the remainder. Exclusive weak right-handers (Rw: N = 15) usually used the right hand for three or more activities, and always used the right hand for the remainder. Predominant right-handers (Rp: N = 18) preferred the right hand for most items, but used the left hand for at least one activity. These groups did not differ on three measures of relative skill of the two hands: peg-moving, tapping and dotting. Groups Rs and Rw were also indistinguishable in terms of the hand used for reaching for cards placed in different spatial positions. However, the reaching measure did discriminate group Rp, which included some individuals who reached predominantly with the left hand. It is concluded that preference batteries should quantify degree of hand preference in terms of the number of activities for which a preference is shown, ignoring the distinction between 'usually' and 'always'. The behavioural reaching measure shows promise as a method for providing a unitary scale of hand preference.

Adult↗
PubMed1995

Phonological awareness and literacy development in children with expressive phonological impairments.

This study investigated the link between expressive phonological impairments, phonological awareness, and literacy. Previous investigations of literacy skills in children with speech impairments have given mixed results; here we considered whether presence of additional language impairments or severity of the speech impairment was an important prognostic factor. Thirty-one children with expressive phonological impairments were compared with control children matched on age and nonverbal ability on three occasions, at mean ages of 70, 79, and 91 months. On each occasion they were given three tests of phonological awareness: one involved rime-matching and two involved onset-matching. At assessments 2 and 3 literacy skills were assessed. Children with phonological impairments scored well below their controls on phonological awareness and literacy, independent of whether or not they had other language problems. Although many of them knew letter sounds, they were poor at reading and writing nonwords as well as real words. It is suggested that both the speech impairment and the literacy problems arise from a failure to analyze syllables into smaller phonological units. The severity of the phonological problems in relation to age is an important determinant of literacy outcome; children who have severe expressive phonological impairments at the time they start school are at particular risk for reading and spelling problems.

Age Factors↗
PubMed1995

Genetic basis of specific language impairment: evidence from a twin study.

Concordance rates were compared for 63 monozygotic (MZ) and 27 dizygotic (DZ) same-sex twin pairs, aged seven years and over, selected because at least one twin met diagnostic criteria for specific speech or language impairment. There was significant heritability for developmental speech and language disorder, defined according to DSM-II-R criteria. When the definition of the phenotype was broadened to include those with a past history of disorder and those with a less pronounced discrepancy between verbal and non-verbal ability, concordance for MZ twins was close to 100 per cent, and that for DZ twins approximately 50 per cent. There was also close similarity between concordant twins for type of disorder. There is good evidence that genetic factors play a role in the aetiology of speech and language impairment; twin data may help us arrive at a clearer conception of the phenotype as well as quantifying the extent of the genetic contribution.

Adolescent↗
PubMed1994

Is specific language impairment a valid diagnostic category? Genetic and psycholinguistic evidence.

Specific language impairment (SLI) is diagnosed when a child fails to develop language normally for no apparent reason: hearing and intelligence are adequate and the social environment is unexceptional. Definitions of SLI typically specify that the child must have a substantial discrepancy between language ability and non-verbal IQ. However, data from a twin study question the validity of this requirement, and indicate that SLI is not genetically distinct from less specific disorders where language impairment occurs in the context of low average or borderline non-verbal ability. A second question concerns the heterogeneous language symptoms seen in SLI: do these correspond to distinct conditions, or to different phenotypic manifestations of a common underlying disorder, or are they merely random variations resulting from unreliable assessments? The last of these possibilities is ruled out by the finding that twins who are concordant for language disorder show good agreement in terms of the pattern of language impairment. However, systematic variation in the age and ability of children in different SLI subgroups suggest that these may correspond to variable manifestations of a core inherited language disorder, rather than distinct diagnostic entities.

Cognition Disorders↗
PubMed1992

Manipulation of visual mental images in children and adults.

Recently, there has been a debate on whether visual patterns can be transformed and reinterpreted in mental imagery. In the present study, task demands and age of subjects were manipulated to see whether children and adults were able to discover a novel visual pattern after transforming a mental image. Two tasks, called combination and subtraction, were devised. They consist of either compounding or taking away parts of images to discover a new construal. Results indicate that not only adults, but also children aged 6 and 10, are able to transform a mental image so as to yield another image with a different interpretation. Task demands had a greater effect on children than adults, consistent with the suggestion that the ease of manipulating mental images is a function of the efficiency of control processes.

Adult↗
PubMed1992

The measurement of handedness: a cross-cultural comparison of samples from England and Papua New Guinea.

Handedness was compared in 125 English children and 185 young people from Papua New Guinea (PNG). Many of the latter were unfamiliar with implements such as pencils and spoons. The PNG subjects showed strong hand preferences, usually for the right, and on some items were more consistent in hand use than the English subjects. However, they had smaller hand differences on peg-moving and tapping than the English children. A factor analysis identified one factor with high loadings from items involving precise motor control, and another with positive loadings from only card-dealing, block-building and threading. The first factor was impervious to cultural influences, whereas the second showed considerable cultural variation.

Adolescent↗
PubMed1992

Influence of short-term memory codes on visual image processing: evidence from image transformation tasks.

Three experiments showed that phonological recording of visual stimuli in short-term memory (STM) affects coding in long-term memory (LTM) and therefore performance on tasks involving generation and manipulation of visual images of the stimuli. An image transformation task was devised. It consists of mentally subtracting a part of an image to discover in the remainder another object. In Experiment 1, Ss were required to learn a set of easily nameable visual stimuli and then perform the subtraction task on images retrieved from LTM. Performance was significantly better when initial learning was accompanied by articulatory suppression (AS). Experiment 2 confirmed that AS had no effect when the task was performed on an image of a just-presented stimulus. In Experiment 3, the nameability of the stimuli was manipulated. The results replicated the effect of AS for items that were easy to name but showed no effect of AS for stimuli that were difficult to name.

Adult↗
PubMed1992

Comprehension problems in children with specific language impairment: literal and inferential meaning.

A group of 61 schoolchildren with specific language impairment (SLI) was compared with a control group on a comprehension task, in which the child was questioned about a story that had been presented either orally or as a series of pictures. Half the questions were literal, requiring the child to provide a detail that had been mentioned or shown explicitly in the story. The remainder required the child to make an inference about what had not been directly shown or stated. SLI children were impaired on this task, even after taking into account "comprehension age," as assessed on a multiple-choice test. However, the effects of mode of presentation and question type were similar for control and SLI groups. Children who fitted the clinical picture of semantic-pragmatic disorder had lower scores than other SLI children on this task. In addition, they were more prone to give answers that suggested they had not understood the question. However, as with the other SLI children, there was no indication that they had disproportionate difficulty with inferential questions. It is concluded that SLI children are impaired in constructing an integrated representation from a sequence of propositions, even when such propositions are presented nonverbally.

Child↗