Expected vs. real individual alpha frequency: testing an age-based model of vigilance performance

Sustained attention deteriorates systematically during prolonged tasks, transitioning through a vigilance decrement after 15–20 minutes detectable from an increased intra-individual response time (RT) variability rather than an overall slowing. This exploratory study examined whether resting-state Individual Alpha Frequency (IAF) - the dominant EEG alpha-band peak, proposed as a marker of visual processing rate - predicts attentional stability within the vigilance decrement transition. After excluding five participants for data quality or ceiling-level performance, thirteen healthy young volunteers completed an asymmetric visual Go/No-Go task (~40 min, 5 blocks; 80% GO, 20% No-Go). High density 128 channels Resting-state EEG was recorded pre-task (eyes-closed); IAF was estimated via spectral peak (PAF) and centre-of-gravity (CoG) methods. The primary measure was the coefficient of variation of correct GO RTs (CV_RT), indexing intra-individual instability independently of mean speed. Results show that higher IAF values were associated with greater CV_RT in the attentional transition phase (Blocks 2–3, minutes 8–24; ρ CoG = .709, p = .007), without a corresponding effect on mean RT. No significant association emerged in the later phase (minutes 24–40). Speculatively, these patterns may reflect distinct individual modes of attentional regulation across task time, rather than differential performance quality per se. Higher-IAF individuals appear to show greater early instability before stabilizing, while lower-IAF individuals maintain a flatter profile throughout the task. Given the exploratory design and small sample (N = 13), findings are hypothesis-generating. Resting-state IAF emerges as a possible neurophysiological marker of individual attentional regulation during the critical transition phase of prolonged cognitive tasks.