Florence Curt

Manual skill, hand skill asymmetry, and cognitive performances in young children

A total of 1022 children aged 3 to 6 years were examined in their preschools and 27% of them were followed up for 2 years. A computerised version of the peg‐moving task was used repeatedly to assess hand skill of the dominant and the nondominant hand. Cognitive performance was repeatedly evaluated by tasks involving speech, vocabulary, phonological memory, and visual‐spatial skills. Results showed that: (i) age, sex, and handedness effects on hand skill asymmetry generally confirmed previous reports, especially by Annett (2002); (ii) visual‐spatial and vocabulary tasks were significantly related to hand skill but speech and phonological memory tasks were not, and the role of the dominant and nondominant hand were similar; (iii) overall, manual laterality indexes were only weakly associated to some cognitive abilities; (iv) early manual skill was more strongly associated to cognitive tasks than later manual skill. These results fit the assumption of a significant role of early manual behaviour in aspects of cognitive development not relying exclusively on phonology, and raise questions about cognitive development and rehabilitation of children with early occurring manual deficiencies.

Distributions of hand preference and hand skill asymmetry in preschool children: Theoretical implications

We describe the distributions of hand skill asymmetry for the Peg-moving task and the Graphic test among 765 preschool children. A single normal component was observed for the Peg-moving task, but two normal components for the Graphic test, which corresponded primarily to the right- and left-handed children. Hand Preference and Graphic test hand skill asymmetry were age-dependent, but there was no age effect on the PMT hand skill asymmetry. Results are discussed in relation to the Annetts Right Shift theory.

Decreased sensitivity to facial emotions in adolescents with Borderline Personality Disorder.

Whereas severe relationship dysfunction in BPD is well described in adolescence, little is known about the way these patients process facial expressions of emotion. Because few data are available regarding this issue, the present study compared the sensitivity to morphed facial emotional expressions of 22 BPD female adolescents versus 22 matched controls. Participants had to identify as rapidly as possible the various emotions displayed progressively and continuously on faces. Results indicate that adolescents with BPD are less sensitive to facial expressions of anger and happiness, i.e. they require more intense facial expressions than control participants to correctly identify these two emotions. However, they did not exhibit any deficit in recognizing fully expressed emotions. These results suggest that sensitivity to facial emotions is impaired in adolescents with BPD. Theoretical and clinical implications are discussed.

Parental hand preference and manual functional asymmetry in preschool children

Hand preference and hand skill in 1150 normal children between 3 and 6 years of age and hand preference of their parents were assessed to study the effect of parental hand preference on different dimensionsl of manual asymmetry in children. Children hand skill was measured with a computerized version of the Peg Moving Task which allowed us to split the overall performance into two components, a “transport time” and a “search time.” Paternal and maternal left-handedness was significantly related to child left-handedness. Both components of hand skill asymmetry were reduced with mothers left-handedness and one component (search time) with fathers left-handedness. A significant impact of parental hand preference on child hand skill asymmetry, after controlling for child hand preference, was observed. When this analysis was limited to strong right-handed children, a greater paternal effect on child hand skill emerged. These results show the usefulness of performance tasks in detecting parent-child associations concerning manual functional asymmetry.

Eye Dominance in Children: A Longitudinal Study

In a sample of 807 normal preschool children aged from 3 to 6, examined eye dominance was not associated with the declared eye dominance of their parents. Forty percent of the children showed left-eyedness. Eyedness was associated with handedness and not significantly related to age group or sex. A strong relationship between the answers of the two parents concerning eye preference was observed. Two hundred forty-four children were followed-up for 2 years. The examinations were carried out once every 6 months. Two thirds of the children showed perfect stability in eye dominance. There was some evidence that stability in eye use tends to increase with age and to be lower in left-handed children with left-handed parents. There is, at present, very little evidence of a positive association between eye dominance in parents and that in their children.

Evolution of Degree and Direction of Hand Preference in Children: Methodological and Theoretical Issues

This paper presents some methodological and theoretical issues based on a longitudinal study, performed in schools, on hand preference of 256 children, initially aged 3–6 years. Three phenomena are observed: (1) the well-known asymmetry of the hand preference distribution, which probably depends on biological factors; (2) a weak “towards the right” tendency with increasing age, which could be explained by environmental factors; and (3) a strong increase in the degree of hand preference with age which could be a consequence of the subjects own activity. Handedness is considered here as a possibly interesting model to delineate the respective role of biological, environmental, psychological, and pathological factors involved in a simple human behaviour.

Birth order and month of birth are not related with handedness in a sample of 9370 young men.

Abstract In a large representative sample of young men, no clearly significant relationship between handedness and birth order or season of birth was found; the trend was opposite to that claimed by Bakan (1971) and Badian (1983) .

COMPARING LEFT AND RIGHT HAND IN LINE BISECTION AT DIFFERENT AGES

Sixty preschool children (31 boys, 29 girls, 5–6 years old), 60 young adults (30 men, 30 women, 20–45 years old), and 66 older adults (23 men, 43 women, 60–94 years old), bisected 11 lines of different lengths, 1 time with each hand. All participants were French and right‐handed. In all age and sex groups the mean transection was at the left of the true center regardless of the hand used. Accuracy of the left hand was better than accuracy of the right hand in children, but the opposite pattern was observed in older participants (better right hand), and there were no between‐hands differences in accuracy among young adults. The observed patterns of correlation between the left and the right hand, which were age and sex dependent, are presented. These results are discussed in relation to age‐related changes in hemispheric interaction and to the need for additional research on the reliability and extent of the “neglect” in normal individuals.