Biomedical subjects

Karen E Waldie

Publications and source records attributed to Karen E Waldie.

7 recordsLinked to original sources

PubMed2006

Hemispheric functioning in children with subtypes of attention-deficit/hyperactivity disorder.

OBJECTIVE: The authors investigated line bisection performance in children with Attention-Deficit/Hyperactivity Disorder (AD/HD) subtypes. Previous research with neurotypical children found a rightward bias with right-hand use and a leftward bias with left-hand use; however, research with AD/HD participants has failed to similarly measure the effects of hand use, which was the focus of this study. METHOD: Line bisection was used to measure differences in right hemisphere functioning in children (7 to 12 years) with AD/HD-I and AD/HD-C. RESULTS: Initial AD/HD group findings (without subtype differentiation) replicated previous research. However, further subtype analyses showed that the ADHD-I and ADHD-C groups perform significantly differently. Specifically, the ADHD-I group showed a leftward bias, irrespective of hand use, and the ADHD-C group showed a rightward bias, irrespective of hand use. CONCLUSION: These findings suggest that the subtypes represent two distinct disorders and that, unlike ADHD-C, ADHD-I may not be the result of right hemisphere dysfunction.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

The effects of redundant stimuli on visuospatial processing in developmental dyslexia.

The interhemispheric deficit theory of dyslexia postulates that reading difficulties can arise from abnormal communication/collaboration between the cerebral hemispheres. A currently popular way to gather information about interhemispheric processing and integration is with the redundant stimuli task, where participants respond to stimuli presented to the left visual field, right visual field, or both visual fields simultaneously. In neurologically normal individuals, response times to bilateral simple stimulus presentations are faster than response times to a single stimulus in either visual field alone (referred to as redundancy gain). In contrast, individuals with no corpus callosum exhibit greater redundancy gains than would be expected by probability summation. In the present study, 11 children with phonological dyslexia showed a similar "over violation" of the probability (race) model when responding with the left but not the right hand. This asymmetry was not found in age- and IQ-matched control children. The results are at least partially consistent with the notion of phonological dyslexia involving deficits in the transfer of information across the corpus callosum.

Articulation Disorders↗

PubMed2003

Age-related improvements in auditory temporal resolution in reading-impaired children.

Individuals with developmental dyslexia show impairments in processing that require precise timing of sensory events. Here, we show that in a test of auditory temporal acuity (a gap-detection task) children ages 6-9 years with dyslexia exhibited a significant deficit relative to age-matched controls. In contrast, this deficit was not observed in groups of older reading-impaired individuals (ages 10-11 years; 12-13 years) or in adults (ages 23-25 years). It appears, therefore, that early temporal resolution deficits in those with reading impairments may significantly ameliorate over time. However, the occurrence of an early deficit in temporal acuity may be antecedent to other language-related perceptual problems (particularly those related to phonological processing) that persist after the primary deficit has resolved. This result suggests that if remedial interventions targeted at temporal resolution deficits are to be effective, the early detection of the deficit and early application of the remedial programme is especially critical.

Adult↗

PubMed2003

Line bisection following hemispherectomy.

Two left- and right-hemispherectomized patients with contralateral hemianopia and 20 normal controls were administered a line bisection task. All hemispherectomized patients showed a strong bisection bias towards their blind visual field. This contralateral bias persisted when patients were forced to start scanning within their blind hemifield, supporting the idea of a strategic adaptation of attention towards the blind visual field. In all patients the hemispherectomy was performed as a result of cortical abnormality (congenital or acquired) and therefore early changes in functional cerebral organization may have occurred in these patients. The absence of a neglect-like ipsilateral bias and the presence of a hemianopic-like contralateral bias in line may represent a functional deficit or suggest that plastic changes following hemispherectomy induced an adaptive functional re-organization of spatial attention in both left- and right-hemispherectomized patients.

Adaptation, Physiological↗

PubMed2003

Developmental changes in line bisection: a result of callosal maturation?

Normal adults tend to bisect horizontal lines to the left of the objective middle, especially when using the left hand. This bias has been attributed to the dominance of the right hemisphere in spatial attention. The authors investigated the effect of hand use and line position in visual line bisection in right-handed children and adults, classified into 4 different age groups: 10-12, 13-15, 18-21, and 24-53 years (N = 98). All 4 groups showed the characteristic leftward bias when using the left hand. When using the right hand, the youngest group showed a rightward bias, whereas the other 3 groups all showed a leftward bias. This suggests a shift from contralateral to right-hemispheric control during puberty and may reflect maturation of the corpus callosum.

Adolescent↗

PubMed2002

Migraine and cognitive function: a life-course study.

OBJECTIVE: To investigate the association between migraine and cognitive ability among members of a longitudinal birth cohort study. METHODS: Headache status was determined at age 26 (migraine, tension-type headache [TTH], headache-free control subjects) according to International Headache Society criteria, and data relating to cognitive and academic performance from ages 3 to 26 years were analyzed. RESULTS: Study members diagnosed with migraine were subtly but significantly impaired, compared with those with TTH and headache-free control subjects, on tests of verbal ability (especially language reception) from ages 3 to 13, independent of headache history. Performance on other tasks, including reading, arithmetic, motor, and spatial ability, was normal. The association between migraine and verbal functioning also appeared to impact on later academic success. CONCLUSION: Findings suggest that the poorer verbal performance was unlikely to have resulted from cumulative attacks and may be due to developmental factors beginning in utero.

Adult↗

PubMedDate not supplied

The burden of illness associated with headache disorders among young adults in a representative cohort study.

This study investigated the functional impairment (work and social functioning and general health status) associated with migraine and tension-type headache (TTH) among young adult members of the Dunedin Multidisciplinary Health and Development Study. Using criteria based on the International Headache Society classificatory system, the 1-year prevalence for migraine headache was 7.4%, TTH was 11.1%, and combined headache (coexisting migraine and TTH) was 4.3%. All comparisons were against a health control group (headache free) and a diagnostic control group (individuals without headache currently using medication for asthma). Although those suffering from migraine and combined headache had the most severe impairment in work- and social-related activities, those with TTH reported significantly poorer social and mental health functioning and poorer emotional and physical functioning while performing everyday roles than did headache-free controls. Study members with combined headache had the poorest self-reported health, with significantly lower ratings on physical, vitality, and mental health measures than asthmatics currently using medication. The pervasive impairment reported across multiple life domains among young headache sufferers illustrates the significant burden of illness associated with headache disorders.

Adult↗