Comparable neural and behavioural performance in dominant and non-dominant hands during grasping tasks

Abstract

Hand dominance has long been associated with differences in neural control and motor performance, with the dominant hand typically exhibiting better coordination in reaching tasks. However, the extent to which this dominance influences performance in finger force control remains unclear. This study aimed to examine the behavioural and neural features of the dominant and non-dominant hands during grasping and lifting tasks in healthy young adults, focusing on the synergy index, EEG band power, and EEG-EMG coherence as key measures. Twenty right-handed adults (mean age = 26.95, STD = 2.68) participated in this study. Participants engaged in an experimental task where they grasped a handle for the initial five seconds, followed by lifting and holding it for an additional five seconds. There were two task conditions: fixed (thumb platform secured) and free (thumb platform movable). They performed 25 trials with both the dominant and non-dominant hands in the two task conditions, with the order of trials and hands block randomized to eliminate potential order effects. Contrary to the dynamic dominance hypothesis, we found statistical equivalence in the synergy index, EEG band power, and EEG-EMG coherence between the dominant and non-dominant hands across both fixed and free task conditions. These findings suggest that both hands are capable of achieving similar levels of performance in tasks emphasizing steady-state force maintenance, despite the typical advantages of the dominant hand in other motor tasks. While task-dependent modulations in behavioural and neural features were observed due to changes in friction, these adjustments were non-different between the dominant and non-dominant hands.