Motor imagery perspective and brain oscillations characteristics: Differences between right- and left-handers

Motor imagery (MI) encompasses kinesthetic motor imagery (KMI), internal visual-motor motor imagery (IVMI), and external visual-motor motor imagery (EVMI). This study explored α/β oscillations during MI of left-/right-hand movement from KMI/IVMI/EVMI perspectives in a group of left- (N = 20) and right-handed (N = 20), volunteers selected based on their laterality quotient (RH > 80; LH > -80). We analyzed changes in the power of α/β oscillations from visual- and motor-related clusters of independent components, connectivity (imaginary part of coherence; ICOH) between electroencephalographic activity from selected regions of interest (ROIs), and the correctness of the MI. The left-handed individuals showed more robust α/β activity in visual-related ROI during EVMI for their non-dominant hand, compared during IVMI. However, they did not show a difference in brain activity for EVMI/IVMI compared with KMI and connectivity variance across EVMI/IVMI and KMI. The right-handed individuals exhibited visual area suppression during KMI, which could signify focusing on internal sensations and blocking visual processing in this condition. ICOH connectivity in the RH group varied depending on the task and hand involved, with more robust connections for EVMI of the non-dominant hand compared with IVMI and stronger connections for EVMI and KMI of the non-dominant hand compared with the dominant hand. The results suggest that left-handed individuals rely more on visual representations during MI, especially for their non-dominant hand. At the same time, right-handed people may create more multimodal images during the same tasks.