Elevated levels of mixed-hand preference in dyslexia: Meta-analyses of 68 studies

Julian Packheiser; Marietta Papadatou-Pastou; Angeliki Koufaki; Silvia Paracchini; Clara C Stein; Judith Schmitz; Sebastian Ocklenburg

doi:10.1016/j.neubiorev.2023.105420

Elevated levels of mixed-hand preference in dyslexia: Meta-analyses of 68 studies

Neurosci Biobehav Rev. 2023 Nov:154:105420. doi: 10.1016/j.neubiorev.2023.105420. Epub 2023 Sep 30.

Authors

Julian Packheiser¹, Marietta Papadatou-Pastou², Angeliki Koufaki³, Silvia Paracchini⁴, Clara C Stein⁵, Judith Schmitz⁶, Sebastian Ocklenburg⁷

Affiliations

¹ Social Brain Lab, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands.
² School of Education, National and Kapodistrian University of Athens, Athens, Greece; BioMedical Research Foundation of the Academy of Athens, Athens, Greece. Electronic address: marietta.papadatou-pastou@seh.oxon.org.
³ School of Education, National and Kapodistrian University of Athens, Athens, Greece.
⁴ School of Medicine, University of St Andrews, St Andrews, UK.
⁵ Division of Forensic Psychiatry, Department of Psychiatry, Psychotherapy, and Preventive Medicine, LWL-University Hospital Bochum, Bochum, Germany.
⁶ Biological Personality Psychology, Georg-August-University Goettingen, Goettingen, Germany.
⁷ Department of Psychology, Medical School Hamburg, Hamburg, Germany; ICAN Institute for Cognitive and Affective Neuroscience, Medical School Hamburg, Hamburg, Germany; Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University Bochum, Bochum, Germany.

PMID: 37783301
DOI: 10.1016/j.neubiorev.2023.105420

Abstract

Since almost a hundred years, psychologists have investigated the link between hand preference and dyslexia. We present a meta-analysis to determine whether there is indeed an increase in atypical hand preference in dyslexia. We included studies used in two previous meta-analyses (Bishop, 1990; Eglinton & Annett, 1994) as well as studies identified through PubMed MEDLINE, PsycInfo, Google Scholar, and Web of Science up to August 2022. K = 68 studies (n = 4660 individuals with dyslexia; n = 40845 controls) were entered into three random effects meta-analyses using the odds ratio as the effect size (non-right-handers; left-handers; mixed-handers vs. total). Evidence of elevated levels of atypical hand preference in dyslexia emerged that were especially pronounced for mixed-hand preference (OR = 1.57), although this category was underdefined. Differences in (direction or degree) of hand skill or degree of hand preference could not be assessed as no pertinent studies were located. Our findings allow for robust conclusions only for a relationship of mixed-hand preference with dyslexia.

Keywords: Dyslexia; Handedness; Hemispheric asymmetry; Laterality; Reading.

Publication types

Meta-Analysis
Review

MeSH terms

Dyslexia*
Functional Laterality*
Hand
Humans
MEDLINE
Odds Ratio