Open Communication Can Lead to Equivalent EEG Data Quality for Black Women: Multilevel Modeling Interindividual...

Black participants are often excluded from electroencephalography (EEG) studies due to perceived difficulty in achieving acceptable electrode impedance for participants with tightly curled hair. This has led to unrepresentative samples and poor external validity in EEG research. Here we apply and validate contemporary recruitment and preparation recommendations to replicate emotional perception effects in a diverse sample and investigate an inconsistent finding in the ingroup/outgroup face processing literature. This was achieved via Bayesian multilevel modeling to assess signal-quality at the level of individual participants. Here three groups, including Black women, White women, and a group excluding Black and White women viewed emotionally arousing and neutral naturalistic scenes, as well as matched portraits of Black and White male faces. The modulation of onset-evoked ERPs including the P100, N170, early posterior negativity (EPN), and late parietal positivity (LPP) was analyzed to understand interindividual differences in categorical effects. With minor adjustments to recruitment and electrode cap placement procedures, no data from Black participants were excluded, and EEG artifacts and signal-quality were equivalent or better for all participants relative to those in the other groups. The ERP results showed strong consistency across the sample groups, replicating patterns of EPN and LPP modulation across 6 scene categories. Relative to White faces, portraits of Black faces evoked larger amplitudes in the N170, EPN, and LPP across all participant groups. The N170 was modestly predicted by rated arousal of the face portraits and self-reported quantity of outgroup social contact, but these moderators did not explain the large amplitude differences. Interpretations are considered, including the possibility that portrait lighting may be less suitable for Black faces, thus increasing a demand for configural processing associated with N170 amplitude. More speculatively, cultural stigmatization effects in the United States may also contribute to experienced arousal and ERP modulation across all groups.