Investigating bimanual coordination in dominant and non-dominant virtual hands

Abstract

A bias in attention towards the dominant hand has been cited as a possible factor in the lateralisation of human bimanual coordination (Peters, 1981). A mirror was placed between the hands of 18 dextral participants performing rhythmic anti-phase movements. This set-up gave the appearance of a reflected virtual hand (moving in time with the un-occluded hand), in the same spatial location as the occluded left or right hand. This asymmetrical conflict between vision and action examined whether the left hand would show higher levels of error when replaced by a virtual right hand than the converse condition. Higher levels of error were observed during performance of the anti-phase pattern overall in the conditions where the mirror was present (compared to control conditions without the mirror). However, this effect did not differ between hands. The implications for the mirror paradigm, possible explanations for the lack of asymmetry, and the consequences for the attentional bias hypothesis are discussed.

Keywords:

• Attentional bias
• Bimanual coordination
• Virtual hands
• Mirror

Acknowledgements

The authors would like to thank Dr Mark Mon-Williams and Dr Andrew Wilson for their insightful comments on an early draft of this manuscript. J. Randall Flanagan (Queens University, Kingston, Canada) developed the 3Wave software. The first author was supported by a 6th Century studentship from the College of Life Sciences and Medicine at the University of Aberdeen.

Notes

¹It should be noted that, despite the re-scaling procedures described above, the data may be subject to small inaccuracies where the oscillations are not fully harmonic.

²In the mirror condition, looking towards the right during the task forces participants to direct their attention towards a reflection of the left hand. Due to their proximity to one another, both hands were visible to participants under leftward and rightward visual conditions.