Catecholaminergic Modulation of Metacontrol is Reflected by Changes in Aperiodic EEG Activity.

BACKGROUND: "Metacontrol" describes the ability to maintain an optimal balance between cognitive control styles that are either more persistent or more flexible. Recent studies have shown a link between metacontrol and aperiodic EEG patterns. The present study aimed to gain more insight into the neurobiological underpinnings of metacontrol by using Methylphenidate (MPH), a compound known to increase postsynaptic catecholamine levels and to modulate cortical noise.

METHODS: In a double-blind, randomized, placebo-controlled study design, we investigated the effect of methylphenidate (0.5 mg/kg) on aperiodic EEG activity during a flanker task in a sample of n = 25 neurotypical adults. To quantify cortical noise, we employed the FOOOF (fitting oscillations & one over f) algorithm.

RESULTS: Compared to placebo, MPH increased the aperiodic exponent, suggesting that it reduces cortical noise in two ways: First, it did so in a state-like fashion, as the main effect of the drug was visible and significant in both pre-trial and within-trial periods. Second, the electrode-specific analyses showed that the drug also affects specific processes by dampening the downregulation of noise in conditions requiring more control.

CONCLUSIONS: Our findings suggest that the aperiodic exponent provides a neural marker of metacontrol states and changes therein. Further, we propose that the effectiveness of medications targeting catecholaminergic signaling can be evaluated by studying changes of cortical noise; fostering the idea of using the quantification of cortical noise as an indicator in pharmacological treatment.