Table 1. Analytical decisions and parameters investigated in the multiverse analysis.

Parameters in italics are the ones used in the pre-registered analysis. In total 48 different combinations of parameters (specifications) were investigated.

Analytical decision	Parameter	Description
Epoch length	2 s	Length of the epochs in seconds. Epoch length affects the frequency resolution of the power spectrum. ‘2 s’ implies a frequency resolution of 0.5 Hz, ‘5 s’ of 0.2 Hz.
	5 s
Taper	dpss	Method to estimate the power spectrum. ‘Dpss’ performs frequency analysis with multiple dpss tapers and 1 Hz spectral smoothing. ‘Hanning’ performs frequency analysis with a single hanning taper.
	hanning
Avg. psd	yes	Method to summarize aperiodic activity on the mPFC. ‘Yes’ averages the power spectra of all the source locations encompassing the mPFC and derives the aperiodic exponent from this average. ‘No’ models the power spectrum for each location and averages aperiodic parameters obtained from each power spectra.
	no
Fooof range	2–40 Hz	Frequency range in which to model the power spectrum. ‘2–40 Hz’ is the pre-set value of the ‘spectparam algorithm’ (Donoghue et al., 2020). ’40–60’ is the original setting of Gao et al., 2017. ‘1–100’ includes the whole power spectrum.
	40–60 Hz
	1–100 Hz
Fooof knee	no	Parameter that controls the bend of the model of aperiodic activity. ‘No’ omits the estimation of the knee. ‘Yes’ models the knee.
	yes