deficient and constrained in asymmetric movements, indicating the high tendency of the CNS toward pro- ducing symmetric or similar movements (Swinnen, 2002; Swinnen, Dounskaia, & Duysens, 2002). This shows that bimanual skills have a different method of control from that of unimanual movements, especially when each part of the body simultaneously makes a different movement temporally and spatially (Vanghe- luwe, Suy, Wenderoth, & Swinnen, 2006). Regarding how bimanual movements are controlled by the CNS, there have been various theories in whose interpretation of these movements there are critical contradictions and differences. The intense tendency of the two hands toward producing similar movements in terms of time and space features in bimanual move- ments results in the theory that there is a single motor program for both hands (Schmidt & Lee, 1999). Generalized Motor Program (GMP) theory assumes that the motor representation is independent Introduction Some of the daily motor skills involve precise timing for using both hands. Most of these skills such as open- ing a bottle, typing, or playing the guitar involve using the two hands differently. A good majority of stud- ies have revealed that doing two different tasks with the two hands, when each hand performs a different action simultaneously, incurs bilateral interference even when each hand can perform separately without difficulty (Klapp, Nelson, & Jagacinski, 1998; Kurtz & Lee, 2003). These observations make it clear that the central nervous system (CNS) can control symmetric bimanual movements without any problem while it is * Address for correspondence: Mohammadreza Doustan, De- partment of Motor Behavior, Faculty of Sport Sciences, Shahid Chamran University of Ahvaz, Golestan Blvd., Ahvaz, 61357- 83151 Iran. E-mail: m.doustan@scu.ac.ir Evaluation of learning of asymmetrical bimanual tasks and transfer to converse pattern: Load, temporal and spatial asymmetry of hand movements Mohammadreza Doustan 1, *, Mehdi Namazizadeh 2 , Mahmoud Sheikh 2 , and Naser Naghdi 3 1 Faculty of Sport Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran; 2 Faculty of Sport Sciences, Tehran University, Tehran, Iran; and 3 Department of Neurology, Iran Pasteur Institute, Tehran, Iran Copyright: © 2019 M. Doustan et al. This is an open access article licensed under the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/). Background: In most daily activities, we are required to use both hands. In many motor skills like playing guitar, the left and right hand must perform asymmetric movements with different timing. Objective: The aim of the study was to evaluate the effect of learning in various asymmetrical bimanual tasks and to evaluate the transfer to tasks with converse hand movements. Methods: Thirty right-handed male students (age 21.5 ± 1.3 years) who had no motor disorders were divided into three groups. Participants of each group were trained for four days after a pretest. All participants performed asymmetrical bimanual drawing of a circle with each hand. Participants in the first group differed in terms of load in each hand, those in the second group differed in the speed of hand movement and those in the third group differed in the range of motion. The test was carried out in simultaneous bimanual movement both as practiced (learning acquisition test) and substitution of patterns between the two hands (transfer test). To analyze the data, repeated measures analysis of variance was performed. Results: For the acquisition test, significant differences were found between the results of the pretest, the posttest, and the retention test across all three groups. In terms of the transfer test, the first group showed a significantly better performance than their performance on the acquisition (p = .001). No such differences were found between the performance of the second group on the two tests (p = .945). Finally, the third group performed significantly better on the transfer test than on the acquisition test. (p = .047). Conclusions: The present study found similar effects of motor learning on various asymmetrical bimanual motor tasks, but different inter-group performance on learning and transfer tasks. Keywords: bimanual coordination, hierarchical control, effector-independent hypothesis Acta Gymnica, vol. 49, no. 3, 2019, 115–124 doi: 10.5507/ag.2019.010