Human laterality for manipulation and gestural communication: A study of beach-volleyball players during the Olympic Games

ABSTRACT

Comparative studies can help understand better brain functional lateralization for manipulation and language. This study investigated and compared, for the first time, human adults’ laterality for manipulation and gestures in a non-experimental social context. We analysed the manual laterality of 48 beach volleyball athletes for four frequently expressed behaviours: a complex throwing action (jump serve) and three gestures (CLAP HAND, PUMP FIST and SLAP HAND-TO-HAND). We evaluated population-level laterality bias for each of the four behaviours separately, compared manual laterality between behaviours and investigated factors influencing gestural laterality. We furthered our between-gestures comparison by taking into account three categories of factors simultaneously: gesture characteristics (sensory modality), interactional context components (positions of interactants and emotional valence), and individual demographic characteristics (age, sex and country). Our study showed that (1) each behaviour considered presented a population-level right-hand bias, (2) differences of laterality between behaviours were probably related to gesture sensory modality and (3) signaller’s laterality was modulated differently in relation to positions of interactants, emotional valence, age and sex. Our results support the literature suggesting that left-hemisphere specialization for manipulation and language (speech and gestures) may have evolved from complex manual activities such as throwing and from gestural communication.

KEYWORDS:

• Brain specialization
• handedness
• non-communicative activities
• gestural signalling
• interactive sport

Acknowledgments

We are indebted to Ann Cloarec for correcting the English. This study was part of a PhD funded by the French Ministry of Research and Technology with additional financial support of Rennes Metropole and the VAS Doctoral School.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability

The datasets generated during and/or analysed during the current study are not publicly available because they are the subject of further studies, but are available from the corresponding author on reasonable request.

Notes

1 From here on, gestures are depicted in lower capitals.

2 Visual field used refers to the recipient's location in the signaller’s visual field. The left visual field is from the direction of the signaller’s head (0°) to the signaller’s left side (180°). The right visual field is from 0° to 180° to the right of the signaller.

3 Only 52 of the 1595 interactions LG collected were recorded as negative. Negative interactions thus represented a very small proportion (3.26%) of the social interactions collected by LG.

Additional information

Funding

This study was part of a PhD funded by the French Ministry of Research and Technology with additional financial support of Rennes Metropole and the VAS Doctoral School.