Associations Between Individual Differences in Cognitive Control Capacity and Multitasking Performance

Background/Objectives: Cognitive control capacity (CCC) describes the maximum volume of information an individual can reliably process per unit time, a key cognitive factor of multitasking performance. While sustained high-load multitasking is known to induce cumulative cognitive impairment, it remains untested whether CCC is associated with vulnerability to this decline across subjective, behavioral, and neural levels. This study systematically characterized how individual differences in CCC relate to multitasking processing ability and examined whether a higher CCC is associated with smaller cognitive fatigue during extended operations. Methods: CCC was assessed in 313 college students via the adaptive MFTA_A paradigm. Participants scoring in the upper and lower 27% of the CCC distribution formed the high-CCC group (n = 42, 3.65 ± 0.33 bps) and the low-CCC group (n = 41, 2.04 ± 0.28 bps). All participants completed a 1 h multitasking information-processing test comprising tracking, instrument monitoring, and listening subtasks. Alertness was measured with the Psychomotor Vigilance Task before and after the test, subjective workload was rated across four Visual Analogue Scale dimensions, and continuous task-state EEG was recorded to analyze spectral power and microstate dynamics. Results: Relative to low-CCC participants, the high-CCC group showed smaller post-test alertness declines, consistently higher multitasking scores across all blocks, and sustained higher theta/alpha ratios and parietal beta power throughout the task. High-CCC participants also exhibited descriptively stronger activation of microstate C and a late rebound pattern in microstate D transitions, while the low-CCC group showed early stabilization of D-state dynamics without compensatory adjustment. Subjective workload ratings rose equivalently across time in both groups, with no significant between-group differences. Conclusions: CCC is strongly associated with multitasking efficiency. Higher CCC is associated with larger information-processing capacity and better sustained performance during high-load work. This association may be supported by more efficient neural resource allocation and more robust cognitive control network engagement, with exploratory evidence of adaptive brain network reorganization under fatigue. CCC is associated with both immediate multitasking performance and alertness maintenance capacity during prolonged operations.