I am asking for your help because we are stuck in our study, we cannot understand why our PSD assumes strange values and consequently the possibility of evaluating a classical engagment index (alpha, beta, theta). The index assumes very low values that do not go beyond 20 and also the components of the waves have very low values. The pipeline that we developed on python, attached, should follow the classic steps for this kind of search: bandpass filter, notch filter, epoching date duration of 4 with sliding of 0.2 and the Welch for the PSD but the results are bad. U can also see it from the images here. We use a configuration of 2 channels with reference in the middle, fronthead and ground on ear. What we are missing? Something related to amplitude, errors in the pipeline or?
Thank you for helping, hope somebody could answer cause I'm gonna hit my head against the wall xD