Search results for "Functional Laterality"
showing 10 items of 274 documents
Decreased prevalence of left-handedness among females with male co-twins: evidence suggesting prenatal testosterone transfer in humans?
2009
Studies of singletons suggest that right-handed individuals may have higher levels of testosterone than do left-handed individuals. Prenatal testosterone levels are hypothesised to be especially related to handedness formation. In humans, female members from opposite-sex twin pairs may experience elevated level of prenatal exposure to testosterone in their intra-uterine environment shared with a male. We tested for differences in rates of left-handedness/right-handedness in female twins from same-sex and opposite-sex twin pairs. Our sample consisted of 4736 subjects, about 70% of all Finnish twins born in 1983–1987, with information on measured pregnancy and birth related factors. Circulati…
A framework for identifying the adaptations responsible for differences in pegboard times between middle-aged and older adults
2017
Time to complete two tests of manual dexterity, the 9-hole Peg Test and Grooved Pegboard Test, increases with advancing age. However, the adaptations responsible for the differences in pegboard times betweenmiddle-aged and older adults are largely unknown. Potential mechanisms include neuromuscular characteristics, cognitive function, and cutaneous sensation. To provide a tractable framework to address these gaps in knowledge, the purpose of the current study was to identify the latent variables underlying age-associated differences in time to complete the 9-hole and grooved pegboard tests. The approach involved an independent component analysis that identified associations between the two …
Event-related potentials in newborns with and without familial risk for dyslexia: principal component analysis reveals differences between the groups
2003
Differences revealed by factor scores extracted by principal component analysis (PCA) from event-related potential (ERP) data of newborns with and without familial risk for dyslexia were examined and compared to results obtained by using original averaged ERPs. ERPs to consonant-vowel syllables (synthetic /ba/, /da/, /ga/; and natural /paa/, /taa/, /kaa/) were recorded from 26 at-risk and 23 control 1-7 day-old infants. The stimuli were presented equiprobably and with interstimulus intervals varying at random from 3,910 to 7,285 ms. Statistically significant between-group differences were found to be relatively similar irrespective of the methods of analysis (original ERPs vs. factor scores…
Functional relevant loss of long association fibre tracts integrity in early Alzheimer's disease.
2007
Abstract The aim of our study was to quantify the structural integrity of the long association fibre tracts in early Alzheimer's disease (AD) and to correlate the findings with the cognitive performance of the patients. We conducted region-of-interest-based analyses of color-coded diffusion-tensor imaging in 12 patients with early AD (age 69.8 ± 8.0 years; MMSE 25.3 ± 1.8) and 16 age- and education-matched healthy controls. Early AD patients showed significantly decreased fractional anisotropy (FA) of the cingulate bundles and the inferior fronto-occipital fascicles bilaterally, whereas FA values of the superior longitudinal fascicles (second division) did not differ significantly between p…
The left occipitotemporal system in reading: disruption of focal fMRI connectivity to left inferior frontal and inferior parietal language areas in c…
2011
Developmental dyslexia is a severe reading disorder, which is characterized by dysfluent reading and impaired automaticity of visual word processing. Adults with dyslexia show functional deficits in several brain regions including the so-called "Visual Word Form Area" (VWFA), which is implicated in visual word processing and located within the larger left occipitotemporal VWF-System. The present study examines functional connections of the left occipitotemporal VWF-System with other major language areas in children with dyslexia. Functional connectivity MRI was used to assess connectivity of the VWF-System in 18 children with dyslexia and 24 age-matched controls (age 9.7-12.5 years) using f…
Refractive lens exchange with Acri.LISA bifocal intraocular lens implantation.
2011
PURPOSE To assess efficacy, safety, and predictability after refractive lens exchange (RLE) in patients who had bilateral implantation of an Acri.LISA 366D diffractive bifocal intraocular lens (IOL). METHODS Sixty-six eyes of 33 consecutive patients were examined after RLE who had bilateral implantation of an Acri.LISA bifocal 366D IOL. Eyes were divided into myopic and hyperopic groups. Monocular uncorrected distance visual acuity, best-corrected distance visual acuity (BCVA), uncorrected distance near visual acuity, and best distance-corrected near visual acuity (BCNVA) were recorded preoperatively and 6 months after surgery. RESULTS Efficacy indexes were 0.73 for myopic and 0.85 for hype…
Effects of Substantia Nigra Stimulation on Electrical and Mechanical Activities of the Duodeno-Jejunal Loop, in the Cat
1985
The effect of substantia nigra stimulation on duodeno-jejunal intraluminal pressure and electrical activity was analysed in the cat. An inhibitory influence was noted to occur on both the intestinal pressure and the electrical response activity (ERA): the effect seemed to be in correlation with the stimulus parameters employed. After bilateral vagotomy, the inhibition remained substantially unchanged. The possibility of the existence of a sympathetic pathway mediating the effect is emphasized.
Mentally Simulated Motor Actions in Children
2009
The present study investigated the effects of age and arm preference on motor imagery ability. Children (groups: 6.5, 8.3, and 10.1 years) and young adults (22.4 years) physically or mentally performed a drawing motor task with the right or the left arm. Imagery ability, accessed by the timing correspondence between executed and imagined movements, was poor at 6 and 8 years but improved at age 10, and was robust in adults. The arm condition had no influence on imagery ability. We suggest that maturation of parietal and prefrontal cortices during development may contribute to improvement of action representation.
MOTOR DYSFUNCTION OF THE "NON AFFECTED" LOWER LIMB: A KINEMATIC COMPARATIVE STUDY BETWEEN HEMIPARETIC STROKE AND TOTAL KNEE PROSTHESIZED PATIENTS
2009
In patients with hemispheric stroke, abnormal motor performances are described also in the ipsilateral limbs. They may be due to a cortical reorganization in the unaffected hemisphere; moreover, also peripheral mechanisms may play a role. To explore this hypothesis, we studied motor performances in 15 patients with hemispheric stroke and in 14 patients with total knee arthroplasty, which have a reduced motility in the prosthesized leg. Using the unaffected leg, they performed five superimposed circular trajectories in a prefixed pathway on a computerized footboard, while looking at a marker on the computer screen. The average trace error was significantly different between the groups of pat…
The test accuracy of the Montreal Cognitive Assessment (MoCA) by stroke lateralisation
2017
Abstract Background The Montreal Cognitive Assessment (MoCA) is an increasingly popular screening tool for detecting cognitive impairment post-stroke. However its' test accuracy by stroke lateralisation is as yet unknown. Aim Our aim was to investigate whether the test accuracy of the MoCA differs by stroke lateralisation across different cognitive domains. Methods We retrospectively examined the cognitive profiles of 228 subacute stroke patients (86 Left, 142 Right), comparing MoCA-total and domain-specific scores with performance on detailed neuropsychological assessment. Results The prevalence of cognitive impairment detected on neuropsychological assessment was high and relatively compa…