Impact of handedness on interlimb transfer depending on the task complexity combined with motor and cognitive skills

• Published in: Neuroscience letters Vol. 785; p. 136775
• Main Authors: Wang, YiFan, Zhao, Jun, Inada, Hitoshi, Négyesi, János, Nagatomi, Ryoichi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10.08.2022
• Subjects: Cross-education; Handedness; Motor Skill Acquisition; Side-dominance; Task Complexity; Motor Skill Acquisition; CRHRP; Cross-education; SLHLP; CRHLP; CLHRP; SRHRP; CLHLP; Handedness; SD; Task Complexity; ANOVA; SLHRP; SRHLP; Side-dominance
• ISSN: 0304-3940; 1872-7972; 1872-7972
• DOI: 10.1016/j.neulet.2022.136775

•Task complexity for skilled motor practice gave different effects on interlimb transfer between right- and left-handed.•The simple task failed to improve performance on the right hand after left-hand motor practice in right-handed subjects.•The complex task resulted in performance improvement on non-trained hands by contralateral motor practice.•A certain level of appropriate complexity is necessary to detect inter-limb transfers in motor learning in right-handed. Task complexity could affect acquisition efficiency of motor skills and interlimb transfer; however, how task complexity affects interlimb transfer remains unclear. We hypothesized that left- and right-handed participants may have different interlimb transfer efficiency depending on the task complexity. Left-hand (n = 28) and right-hand (n = 28) dominant participants (age = 24.70 ± 4.02 years, male:female = 28:28) performed a finger sequence test with two levels of complexity (simple: one-digit with four fingers vs. complex: two-digit with five fingers) before and after ten trials of 2-min practice each on the same apparatus. The speed and task errors were measured and analyzed. Right-handed participants failed to improve performance on their right hand (non-trained hand) after contralateral left-hand practice in the simple finger sequence task. In contrast, the left-handed participants improved performance on non-trained hands both right and left after contralateral practices. In the complex task, however, both the left- and right-handed participants improved performance on non-trained hands by contralateral practices. Our results showed that task complexity of skilled practice gave different effects on interlimb transfer between right- and left-handed subjects. It appears that a certain level of appropriate complexity is necessary to detect inter-limb transfers in motor learning in right-handed subjects.