Background: Mirror therapy is widely used in stroke rehabilitation, yet its immediate task-related cortical responses remain incompletely characterized. We used functional near-infrared spectroscopy (fNIRS) to characterize cortical hemodynamic responses during a mirror task in patients with stroke. Methods: Fifty-one stroke patients with upper limb dysfunction were recruited. Participants performed both a mirror task and a control task, while hemodynamic changes in regions of interest were simultaneously recorded using a 43-channel fNIRS device. General linear model (GLM) analysis was used to compare differences in activation intensity between the mirror task and control task in the cortical regions of interest. Results: Compared with the control task, the mirror task significantly activated 10 channels: CH2, CH3, CH5, CH9, CH11, CH19, CH24, CH25, CH32, and CH33. The activated brain regions were concentrated in the bilateral premotor cortex/supplementary motor area (PMC/SMA), ipsilesional supramarginal gyrus (SMG), ipsilesional primary somatosensory cortex (S1), and contralesional primary motor cortex (M1). Conclusions: The mirror task elicited greater activation than the control task across a distributed cortical network involving bilateral PMC/SMA, ipsilesional SMG/S1, and contralesional M1 in patients with stroke. These findings demonstrate that fNIRS can objectively characterize task-related cortical hemodynamic responses during mirror tasks and provide a basis for future studies linking these cortical response patterns to rehabilitation outcomes.

Background: While caffeine may lower ratings of perceived exertion (RPE) or increase power output at a given RPE, whether caffeinated gum produces these effects during perceptually regulated exercise remains unclear. Aim: This study examined whether caffeinated gum increases self-selected cycling output at regulated-RPE in well-trained male athletes. Methods: Twelve well-trained male athletes (age: 21 ± 2 years; body mass: 77.3 ± 6.0 kg; VO_2peak: 47 ± 4 mL/kg/min) completed randomized, double-blind, placebo-controlled crossover trials separated by 7 days. Athletes chewed caffeinated gum (6 mg/kg) or placebo for 15 min before two 10 min cycling stages at RPE 4 and 7 (0–10 OMNI Scale). Cadence, power output, oxygen uptake, heart rate, and blood lactate concentration were measured. Results: Caffeinated gum significantly increased cadence (RPE 4: 72 ± 7 vs. 66 ± 10 rpm, p = 0.02; RPE 7: 77 ± 9 vs. 71 ± 11 rpm, p = 0.04), total work (53 ± 10 vs. 48 ± 10 kJ, p < 0.01; 87 ± 12 vs. 77 ± 14 kJ, p < 0.01), mean power output (88 ± 16 vs. 79 ± 16 W, p < 0.01; 146 ± 20 vs. 129 ± 24 W, p < 0.01) and peak power output (97 ± 18 vs. 88 ± 17 W, p < 0.01; 166 ± 27 vs. 147 ± 29 W, p = 0.01). Oxygen uptake was also higher in the caffeine condition at both RPE 4 (1.58 ± 0.12 vs. 1.42 ± 0.16 L/min, p = 0.005) and RPE 7 (2.17 ± 0.25 vs. 2.01 ± 0.22 L/min, p = 0.045), whereas heart rate and blood lactate concentration did not differ significantly between conditions (p > 0.05). Conclusion: Caffeinated gum (6 mg/kg) enhances self-selected cycling work at prescribed RPEs, indicating that it alters perceptually regulated exercise intensity in well-trained males.