Asymmetries in the preparation and control of manual aiming movements.

Abstract

Two experiments were conducted to determine if typical right hand target aiming advantages could be reduced or eliminated by increasing the spatial demands of the aiming task. In Experiment 1, we found right hand advantages for both movement time and error regardless of spatial characteristics of the task. When we introduced a greater degree of spatial uncertainty in Experiment 2, subjects exhibited a left hand reaction time advantage. Taken together our results suggest that the right cerebral hemisphere may have a special role to play in preparing the spatial aspects of an aiming movement, while the left hemisphere is more important for movement execution.Resume Deux experiences ont et6 effectuees afin de determiner si l'augmentation des demandes spatiales de la tache de visee pouvait reduire ou eliminer les avantages typiquement reli6s a la main droite lorsque celle-ci s'oriente vers une cible. Dans Pexperience 1, nous avons observe des avantages relies a la main droite pour ce qui est de la duree du mouvement et de la marge d'erreur, peu importe les caracteristiques spatiales de la tSche. Dans Fexp6rience 2 ou le degre d'incertitude spatiale etait plus 61eve, nous avons observe chez les sujets un avantage relie a la main gauche et au temps de reaction. Mis ensemble, les resultats laissent supposer que l'hemisphere cerdbral droit pourrait jouer un role particulier dans la preparation des aspects spatiaux des mouvements dirig6s vers une cible, tandis que I'h6misphere gauche serait plus important pour l'execution des mouvements.Asymmetries in the performance of various manual tasks are often attributed to the proficiency of the contralateral cerebral hemisphere for specific types of processing (Todor & Smiley, 1985). For example, right-hand advantages for finger sequencing (Edwards & Elliott, 1987) and rapid finger tapping (Todor, Kyprie, & Price, 1982) have been ascribed to left hemisphere specialization for the organization and control of sequential movement. Left side superiority for tasks involving tactile discrimination (Benton, Varney, &

Interlimb Differences in Control of Movement Extent

“…In contrast to feedback mechanisms, some authors have proposed a dominant arm/hemisphere advantage for movement planning, initiation, or sequencing (Annett et al 1979;Carson et al 1995;Todor and Kyprie 1980;Todor and Smiley-Oyen 1987). Other studies have suggested a nondominant arm/hemisphere advantage for movement preparation based on left-hand advantages in reaction time (Carson et al 1990;Elliott et al 1993). Thus the idea of differentiating dominant and nondominant arm control by open-or closed-loop control mechanisms alone remains controversial.…”

Eating interrupted: the effect of intent on hand-to-mouth actions

“…These differences between left-and right-handed reach-to-grasp actions are conspicuously absent in many previous grasping studies. Kinematic asymmetries favoring the dominant hand in reach-topoint actions are well documented (Boulinguez et al 2001a;Carson et al 1990Carson et al , 1993Elliott and Chua 1996;Elliott et al 1993;Fisk and Goodale 1985;Elliott 1986, 1989;Velay et al 2001), whereas multiple studies have demonstrated that manual asymmetries in the reach-to-grasp movement are subtle, if not altogether absent (Begliomini et al 2008;Flindall 2012;Flindall et al 2014;Grosskopf and Kuhtz-Buschbeck 2006;Tretriluxana et al 2008). The kinematic asymmetry recently identified during grasp-to-eat movements was interpreted as a right-hand/left-hemisphere advantage for eating, because participants produced smaller MGAs to eat while using their right hand only (Flindall and Gonzalez 2013).…”

Does motor lateralization have implications for stroke rehabilitation?

“…However, studies demonstrating nondominant-arm advantages for reaction time [92][93] have proposed a nondominant specialization for movement preparation.…”