Metacontrol-related aperiodic neural activity decreases but strategic adjustment thereof increases from childhood to adulthood.

The concept of "metacontrol" pertains to the ability to effectively balance cognitive-control styles between extreme persistence and extreme flexibility. Metacontrol relies on the frontal lobe's integrity and is reflected in the degree of aperiodic neural activity in the EEG power spectrum. Given that the frontal lobe undergoes major changes through childhood and adolescence, we predicted that aperiodic neural activity would be more pronounced in underage participants (N = 76, 8 ~ 17 years old) than in young adults (N = 90, 18 ~ 30 years old) performing a Go/Nogo task. As expected, younger participants showed lower aperiodic exponents, indicating a higher level of aperiodic neural activity. We also predicted that adults would be more effective in tailoring their aperiodic brain activity to task-specific requirements. In line with our expectations, adults significantly reduced aperiodic activity in the more control-demanding Nogo condition, whereas underage participants showed no difference between conditions. Age predicted both the reduction of aperiodic activity from the pre-stimulus to the post-stimulus period and the greater reduction of this activity in the more control-demanding conditions. Our findings suggest that aperiodic exponents reflect ontogenetic changes in metacontrol, which in turn can be characterized by a systematic reduction of aperiodic neural activity, and a more strategic adjustment of this activity to task demands with increasing age.