Alpha-Band EEG Modulation as a Potential Aged-Related Biomarker for Biofeedback-Driven Motor–Cognitive Adaptability

Background: Age-related changes in motor–cognitive function are associated with altered neural adaptability, particularly during tasks requiring integration of cognitive and motor processes. Dual-task paradigms are commonly used to assess such interactions; however, gait-based tasks may be unsuitable for older adults with balance impairments. Objective: This study used electroencephalography (EEG) to examine neural modulation during a controlled seated foot-tapping paradigm under dual-task and feedback conditions. Methods: Thirty-six cognitively healthy participants (18 younger adults aged 18–30 years; 18 older adults aged 65–90 years) participated in this study (mean age: 23.8 ± 2.5 years for young adults, 77.0 ± 4.7 years for older adults). The participants performed three tasks: single-task tapping (ST), dual-task tapping with a flanker task (DT), and dual-task tapping with auditory biofeedback (DT+). Relative EEG spectral power across the alpha, beta, and high beta bands was analyzed across left, right, and midline regions. An aggregate modulation index (AMI) was also computed to quantify overall signal changes across the three tested conditions. Results: A significantly greater modulation (p = 0.007) was found in younger adults compared to older adults. In particular, younger adults had significant reductions in alpha activity in DT+ relative to DT across all brain regions (p < 0.02). In contrast, older adults showed no significant alpha modulation across conditions but exhibited increased high beta activity from ST to DT (p < 0.001). Conclusions: These findings suggest that alpha-band EEG activity reflects age-related differences in auditory-feedback-driven neural adaptability, supporting the idea that alpha-band modulation may serve as a potential biomarker of motor–cognitive adaptability.