Combined Action Observation and Motor Imagery Elicits Superior Frontoparietal Activation in Elite Ski Jumpers: An fNIRS Study

Background: Action observation (AO) and motor imagery (MI) are widely used cognitive training strategies. Recent evidence suggests that their combination may enhance motor simulation through synergistic neural mechanisms. However, the effects of this approach on complex whole-body movements in elite athletes remain unclear. Methods: Twenty-seven elite ski jumpers performed AO, MI, and concurrent AO + MI tasks, while cortical hemodynamic responses were recorded using functional near-infrared spectroscopy (fNIRS). Channel-level changes in oxygenated hemoglobin (ΔHbO) were analyzed using one-sample and paired-sample t-tests, with false discovery rate (FDR) correction applied for multiple comparisons. Additionally, mixed-design ANOVAs were conducted to examine the potential modulation of athlete level (master-level vs. first-class). Results: Significant activation was observed only in the AO + MIcondition after FDR correction, primarily in channels corresponding to the precentral gyrus, postcentral gyrus, and middle frontal gyrus. No channels in the AO and MI conditions survived FDR correction. Between-condition comparisons revealed significant differences in several channels located in frontoparietal regions, including the inferior parietal lobule, supramarginal gyrus, and middle frontal gyrus, with AO + MIgenerally showing stronger responses. No significant effects related to athlete level were found. Conclusions: These findings indicate that concurrent AO + MI is more effective than AO or MI alone in eliciting cortical activation in elite ski jumpers. This may reflect enhanced engagement of frontoparietal networks involved in action representation and visuomotor integration. These results may be compatible with a neural efficiency interpretation in highly trained athletes, although further studies with behavioral outcomes and broader skill-level comparisons are needed. AO + MI may represent a promising strategy for off-snow cognitive training in high-risk sports.