Filippos Vlachos

Cerebellum and Reading

Background: Traditionally, the cerebellum has been considered to control coordinated movement. However, in recent years it has been argued that it contributes to higher cognitive functions. Objectives: This review aims to present recent evidence concerning the role of the cerebellum and discusses how it can contribute to reading. Method: The procedure used involves findings coming from three quite different areas, lesion, anatomic and functional imaging studies. Results: These studies indicate a link between cerebellum and reading and its relationship with specific reading difficulties. Conclusions: Our review provides evidence which is in accordance with the recently established role of the cerebellum as a regulator of mental functions and supports theoretical models suggesting that cerebellar deficits might be a cause of developmental dyslexia.

Sex and handedness in development of visuomotor skills

Development of visuomotor skills in 420 left-handed and 420 right-handed school children were investigated using the Rey-Osterrieth Complex Figure. Analysis indicate that the visuomotor skills involved in copying a complex figure improve with age until the mean age of 10.5 yr., in both sex and handedness groups. Further analysis showed that girls performed significantly better than boys at certain developmental stages and right-handers performed better than left-handers in various age groups. Some possible differences in performance could be attributed to different rates of maturation of the cerebral hemispheres, to different neuropsychological strategies, or to functional differences between the sex groups and between right- and left-handed children.

Writing and Drawing Performance of School Age Children Is There Any Relationship

The aim of our study was to investigate possible relationships between writing and drawing performance of school-aged children, in order to compare the two skills at the within-individual level. The sample consisted of 182 right- and left-handed children, aged 8 to 12 years. Children were examined by the Greek adaptation of the Luria-Nebraska neuropsychological battery in spontaneous writing, copying and writing to dictation and they were asked to complete four different drawing tasks. The results produced significant correlations between drawing scores and scores in all three writing tasks. Significant differences in drawing performance among proficient and poor hand writers were also found. On the other hand, there were no significant differences between right- and left-handers’ performance on the above tasks, despite the overrepresentation of left-handed amongst between poor writers. Our findings create a fruitful ground for the further study of early drawing as a means to predict later handwriting problems.

Effects of chronic obstructive pulmonary disease and obstructive sleep apnea on cognitive functions: evidence for a common nature.

Patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea syndrome (OSAS) show similar neurocognitive impairments. Effects are more apparent in severe cases, whereas in moderate and mild cases the effects are equivocal. The exact mechanism that causes cognitive dysfunctions in both diseases is still unknown and only suggestions have been made for each disease separately. The primary objective of this review is to present COPD and OSAS impact on cognitive functions. Secondly, it aims to examine the potential mechanisms by which COPD and OSAS can be linked and provide evidence for a common nature that affects cognitive functions in both diseases. Patients with COPD and OSAS compared to normal distribution show significant deficits in the cognitive abilities of attention, psychomotor speed, memory and learning, visuospatial and constructional abilities, executive skills, and language. The severity of these deficits in OSAS seems to correlate with the physiological events such as sleep defragmentation, apnea/hypopnea index, and hypoxemia, whereas cognitive impairments in COPD are associated with hypoventilation, hypoxemia, and hypercapnia. These factors as well as vascocerebral diseases and changes in systemic hemodynamic seem to act in an intermingling and synergistic way on the cause of cognitive dysfunctions in both diseases. However, low blood oxygen pressure seems to be the dominant factor that contributes to the presence of cognitive deficits in both COPD and OSAS.

Which specific skills developing during preschool years predict the reading performance in the first and second grade of primary school

The aim of this study was to examine if specific skills that are developed during preschool years could predict the reading performance in the first and second grade of primary school. Two hundred and eighty-seven children participated in this longitudinal study. At the kindergarten level, phonological awareness (PA), rapid automatised naming, phonological short-term memory, auditory processing, motor skills and oral language were evaluated. Reading performance was evaluated in Grades 1 and 2 of the primary school. Results showed that not only total reading performance, but the accuracy and the fluency of reading as well, are predicted in the first grade of school by the PA and the phonological memory scores during kindergarten. Oral language plays the most important role in the prediction of text comprehension. Total reading performance and fluency of reading in the second grade were predicted by the PA and the phonological memory scores. In this grade, the PA, the phonological memory and the copy of shapes seem to be important for the accuracy of reading. Our results suggest that the utilisation of such early evidence through intervention programmes at the preschool age and during the first school years could contribute to the prevention of possible reading problems in school children.

VISUAL MEMORY DEFICIT IN CHILDREN WITH DYSGRAPHIA

This study evaluates the performance of children with diagnosed dysgraphia and a control group on the Rey-Osterrieth Complex Figure test. A group of 48 Greek elementary school children aged 6.6 to 12.5 years who were in regular school placement participated. All had been diagnosed with dysgraphia, using the writing scale of the Luria-Nebraska Neuropsychological Battery and were matched with a control group of 48 for sex, age, grade, and handedness. Both groups were administered the test, and the children were examined during copying and mnemonic reproduction of the complex figure. Analysis indicated that there were no significant differences between dysgraphic and nondysgraphic groups during the copying task but the dysgraphic group performed significantly lower during mnemonic reproduction of the Rey-Osterrieth Complex Figure. These results suggest that children with dysgraphia possibly suffer from cognitive difficulties that influence visual memory more than visuomotor skills.

A DEVELOPMENTAL STUDY OF HANDEDNESS IN DOWN SYNDROME PUPILS

Assessed hand preference in 7- to 9-yr.-old and 13- to 15-yr.-old pupils with Down syndrome (n = 41) was compared with control schoolchildren (n = 50) of the same ages. A significant increase in left-handedness and mixed-handedness was noted in Down syndrome groups compared with the normal population. Younger Down syndrome pupils were less consistent in their hand preference than the older pupils and the normal controls.

Explaining age and sex differences in children's handwriting: A neurobiological approach

The present study aimed to assess the effect of age and sex on childrens writing performance, as well as to investigate possible age and sex differences between proficient, intermediate and poor writers. Two hundred and ten children aged 7 to 12 years were examined during spontaneous writing, copying and writing to dictation, using the writing scale of the Luria – Nebraska neuropsychological battery. Results showed a significant effect of age in writing performance. The trend towards writing proficiency in childhood was found to be sex related, while boys were overrepresented among the poor writers. The findings are interpreted on the basis of the neurobiological theories of brain development as well as on the different rates of cerebral maturation between the sexes.

Biological and environmental influences in visuospatial abilities.

Abstract Sex differences in cognition have been the focus of intense debate for years. In this study, we examined the hypothesis that the pattern of sex differences in a visuospatial task may be differential due to environmental factors such as the participation of females in technical and scientific courses. A total of 452 undergraduate students (146 males and 306 females) participated in this study. Results showed a significant effect of academic discipline on both Rey–Osterrieth Complex Figure (ROCF) copy and recall scores. Significant effects of gender were found only on the recall condition. This pattern of results indicates that both gender and academic discipline may influence the performance on a visuospatial task such as ROCF.

VISUOMOTOR ORGANIZATION IN THE LEFT-HANDED CHILD-A NEUROPSYCHOLOGICAL APPROACH

In this study we used the Rey-Osterrieth complex figure to examine the visuomotor organization of 514 boys and girls, aged 5.5 to 20.5 yr. All were left-handed as judged by the Edinburgh Handedness Inventory. Statistical evaluation showed significant differences in the visuomotor organization for boys and girls across the various age groups. Statistically significant differences also appeared between the two sexes at the age groups 7.5 to 8.5 and 8.5 to 9.5, with girls showing better organization than boys.