Laterality, hand control and scholastic performance: a British birth cohort study. Issue 2 (22nd March 2012)

• Record Type: Journal Article
• Authors: Björk, Tabita; Brus, Ole; Osika, Walter; Montgomery, Scott
• Is Part Of: BMJ open. Volume 2:Issue 2(2012)
• Publication Date: 2012-03-22
• Subjects: Medicine -- Research -- Periodicals; 610.72
• DOI: 10.1136/bmjopen-2011-000314
• Languages: English
• ISSNs: 2044-6055

Abstract

Abstract : Objectives: To use simple measures of laterality and hand control that can identify a greater risk of poorer scholastic ability, potentially signalling suboptimal hemispheric lateralisation. Design: Analysis of material from a birth cohort study. Setting: Members of the National Child Development Study, a British birth cohort study following people born in 1958. Participants: 10 612 children who undertook tests at age 11 years. Primary outcome measures: Teacher-administered tests of non-verbal general ability, verbal general ability, reading comprehension and mathematics. Results: Linear regression produced associations (and 95% CIs) with tests of verbal general ability, non-verbal general ability, reading comprehension and mathematics scores for the lowest third (compared with highest) of a left-hand control test involving picking up matches of −1.21 (−1.73 to −0.68; p<0.001), −0.72 (−1.14 to −0.29; p=0.001), −0.70 (−1.06 to −0.35; p<0.001) and −1.32 (−1.90 to −0.73; p<0.001). Among those in the lowest third of the right-hand control test score, mixed-handedness compared with right-handedness was associated with poorer scholastic performance, with regression coefficients (and 95% CIs; p values) of 1.90 (−3.01 to −0.80; p=0.001), −1.25 (−2.15 to −0.35; p=0.007), −1.28 (2.04 to −0.53; p=0.001) and −1.33 (−2.53 to −0.13; p=0.030). The estimates are for a point change in the scholastic test scores, after adjustment for sex, left-hand motor function and social class. Statistically significant associations with mixed-handedness were only observed for the lowest third of right-hand motor function. Conclusions: Measures involving poorer left-hand motor function may represent useful markers of reduced cognitive function possibly reflecting suboptimal hemispheric lateralisation. Crude measures of laterality such as reported non-right-handedness may be more useful for research when combined with measures of motor function.