title: Vertebrate whole-body-action asymmetries and the evolution of right handedness: a comparison between humans and marine mammals.
abstract: As part of a vertebrate-wide trend toward left brain/right side asymmetries in routine whole-body actions, marine mammals show signs of rightward appendage-use biases, and short- and long-term turning asymmetries most of which are unique in non-humans in being just as strong as right handedness, and even stronger than human handedness-related turning biases. Short-term marine mammal turning asymmetries and human about-turning asymmetries share a leading right side, suggesting a commonality in left hemisphere intentional control. The long-term leftward turning bias that both groups share may be an indirect result of both sensory and motor influences on the right side in dolphins, but be induced by a right-hemisphere-controlled spatial/attentional bias to the left in humans. Marine mammals may share, with humans and other higher primates, a left hemisphere specialization for action dynamics, although evidence is currently lacking for human-like right hemisphere specializations relevant to action in other vertebrates.
authors.affiliation: University of Texas at Austin, 606 Harthan St., Austin, TX, 78712, USA. macneilage@psy.utexas.edu
authors.forename: Peter F
authors.initials: PF
authors.lastname: MacNeilage
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000502:physiology*; D005075:Biological Evolution; D001921:Brain / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008322:Mammals
keywords: action; evolution; left hemisphere specialization; marine mammals; right handedness