Evidence for right-handed feeding biases in a left-handed population

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Flindall, Jason W.
Stone, Kayla D.
Gonzalez, Claudia L. R.
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Taylor & Francis
We have recently shown that actions with similar kinematic requirements but different end-state goals may be supported by distinct neural networks. Specifically, we demonstrated that when right-handed individuals reach-to-grasp food items with intent to eat, they produce smaller maximum grip apertures (MGAs) than when they grasp the same item with intent to place it in a location near the mouth. This effect was restricted to right-handed movements; left-handed movements showed no difference between tasks. The current study investigates whether (and to which side) the effect may be lateralized in left-handed individuals. Twenty-one self-identified left-handed participants grasped food items of three different sizes while grasp kinematics were captured via an Optotrak Certus motion capture array. A main effect of task was identified wherein the grasp-to-eat action generated significantly smaller MGAs than did the grasp-to-place action. Further analysis revealed that similar to the findings in right-handed individuals, this effect was significant only during right-handed movements. Upon further inspection however, we found individual differences in the magnitude and direction of the observed lateralization. These results underscore the evolutionary significance of the grasp-to-eat movement in producing population-level right-handedness in humans as well as highlighting the heterogeneity of the left-handed population.
Sherpa Romeo green journal. Permission to archive accepted author manuscript.
Grasp , Left-hand , Kinematics , Prehension , Asymetries , Right-hand , Grasp-to-eat , Grasp-to-place , Grip
Flindall, J.W., Stone, K.D., & Gonzalez, C.L.R. (2015). Evidence for right-handed feeding biases in a left-handed population. Laterality, 20(3), 287-305. doi:10.1080/1357650X.2014.961472.