2.6.5. Data quality evaluation

The quality of every data set was evaluated with regard to its light fall‐off curve, the proportion of measurements retained below the 7.5% temporal standard deviation cutoff, GVTD time course, pulse signal‐to‐noise ratio (SNR) across the cap (computed as the ratio of signal power in the 0.5–2 Hz frequency band to the bandwidth‐scaled median power in flanking frequency ranges across the cap), and for adult imaging sessions also the quality of control word‐hearing task activation maps, as in prior studies (Eggebrecht et al., 2014). Light fall‐off curve assessments excluded measurements bridging the dorsal panel to the rest of the cap, as those source‐detector distances are especially sensitive to head size and placement of the dorsal panel. Sessions and runs with poor data quality based on all the above metrics were excluded from further analysis.