Phenotyping in clinical laterality research: a comparison of commonly used methods to determine mixed-handedness and ambidexterity

ABSTRACT

An increased prevalence of mixed-handedness has been reported in several neurodevelopmental and psychiatric disorders. Unfortunately, there is high between-study variability in the definition of mixed-handedness, leading to a major methodological problem in clinical laterality research and endangering replicability and comparability of research findings. Adding to this challenge is the fact that sometimes researchers use the concepts of mixed-handedness and ambidexterity interchangeably. Therefore, having a consensus on how to determine mixed-handedness and how to distinguish it from ambidexterity is crucial for clinical laterality research. To this end, hand preference and hand performance data from more than 600 participants from the Dortmund Vital Study (Trial registration: ClinicalTrials.gov NCT05155397), a population-based study in Germany, was analyzed to ascertain an optimal classification to determine mixed-handedness and ambidexterity. Using a combination of latent class analyses, effect size determination, and comparisons with the existing literature, we establish that an LQ cut-off criterion of +/−60 for mixed-handedness is optimal for future clinical laterality studies. Moreover, we show that mixed-handedness and ambidexterity are not identical and that the terms should not be used interchangeably. We further highlight the need for a consensus on how to mathematically determine ambidexterity as results of existing categorization schemes largely differ.

Trial registration: ClinicalTrials.gov NCT05155397; https://clinicaltrials.gov/ct2/show/NCT05155397.

KEYWORDS:

• Dortmund vital study
• hemispheric asymmetries
• Edinburgh handedness inventory
• ambisinistrality
• ambidexterity quotient

Acknowledgments

We are grateful to all participants who volunteered to participate in this study and want to thank the team of the Dortmund Vital Study. The study is endorsed by the German Center for Mental Health (DZPG).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data sharing does not apply to this article as no new datasets were generated or analyzed during the current study. All used data were from the Dortmund Vital Study.

Authors contribution

A.M. and S.O. developed key hypotheses. A.M., S.O., E.G., S.G., P.D.G., M.L., and E.W. designed the study. S.G., P.D.G., M.L., and E.W. performed data collection. S.G. and P.D.G. pre-processed the data. S.O. and A.M. run the analyses. A.M. and S.O. wrote the manuscript, with substantial support from all authors. All authors have contributed significantly to the final submitted version of the manuscript.

Additional information

Funding

The Dortmund Vital Study did not receive external funding.