The pantomime of mental rotation: Left-handers are less lateralized. (5th November 2022)

• Record Type: Journal Article
• Authors: Helmich, I.; Meyer, C.; Voelk, M.; Coenen, J.; Mueller, S.; Schepmann, J.; Lausberg, H.
• Is Part Of: Neuropsychologia. Number 176(2022)
• Publication Date: 2022-11-05
• Subjects: Motor-cognition -- Hemispherical specialization -- Pantomime rotation gestures -- Pantomime position gestures -- Handedness; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2022.108385
• Languages: English
• ISSNs: 0028-3932

Abstract

Abstract: Introduction: The conceptualization of skilled hand movements (praxis) may be grounded in hemispherically specialized functions. However, a left-hemispherical advantage of (tool-use) pantomime gestures and a right-hemispherical advantage of spatial gestures may be more prominent in right-handed than left-handed individuals. We therefore investigated the hypothesis that right-handed but not left-handed individuals show a superiority of the left hemisphere (/right-hand preference) for the execution of pantomime (rotation of an object) gestures as well as a right-hemispherical superiority (/left-hand preference) for gestures that depict spatial information (/positioning of an object). Methods : 20 right- and 20 left-handed participants were asked in two experiments to demonstrate with their two hands how to move tachistoscopically (in the left (LVF) or right visual hemifields (RVF)) presented geometric objects of different rotations into an identical final position. Two independent blind raters evaluated the videotaped hand gestures employing the Neuropsychological Gesture (NEUROGES) Coding System. Results: In contrast to left-handed individuals, right-handed individuals present increased pantomime - rotation gestures with the right hand and pantomime - position gestures with the left hand during stimuli presentation in either visual field. Left-handers showed significantly increased left-hand pantomime - rotation gestures during stimulus presentation within the LVF (only). Discussion: Right-handed individuals increase their pantomime - rotation gestures with the right hand to depict motion but use their left hand for pantomime - position gestures to describe spatial relations of the objects. Left-handers do not show a clear lateralization of the right and left hand with regards to either handedness or hemispherically lateralized motor functions. The hemispherical lateralization of praxis functions is therefore more pronounced in right-handed than left-handed individuals. Highlights: The skewedness bias applies equally for right-handed and left-handed individuals. Right- and left-handed individuals use pantomime - rotation gestures to nonverbally depict gravitational unstable objects. Left-handed individuals present reduced hemispherically specialized praxis functions. Pantomime - rotation gestures depend on left-hemispheric functions in right-handed individuals. Pantomime - position gestures depend on right-hemispheric functions in right-handed individuals.