THE ROLE OF BASELINE EEG POWER IN EEG-NEUROFEEDBACK REGULATION

Efficacy of neurofeedback training (NFT) depends on many experimental settings. This poses an important but complex objective of finding an optimal set of protocol parameters. Individual differences in baseline electrical activity represent a crucial part of key protocol parameters.
We employed slow cortical potentials (SCP) neurofeedback. 21 participant underwent 24 neurofeedback (NFT) sessions on separate days, two feedback blocks per same-day session. Each block consisted of 40 trials, presented in randomized order, with different requirements regarding the volitional modification of brain states: 50% required electrical negativity: 50% required electrical positivity trails in the first 12 sessions. In the last 12 sessions, the training aimed for disorder specific regulation (required negativity 80%, required positivity 20%). Each trial was preceded by 2 seconds of baseline and 2 seconds of a “get ready” phases, followed by an 8-second interval of volitional modulation of SCP activity (active regulation phases). Feedback was provided via a visually moving object.
We analyzed EEG relative power within conventional frequency bands separately for the pre-regulation (baseline + “get ready”) phases and for the active regulation phases. Correlations in EEG power changes were computed between the pre-regulation and active regulation conditions.
Our preliminary analysis shows that SCP power in pre-regulation phases significantly correlates with SCP power in active regulation phase, independent of up- or down-regulation trial. We found strong correlations of similar type for lower alpha and gamma EEG frequency bands. Our results indicate that SCP neurofeedback involves several different brain oscillatory and, presumably, several different cognitive mechanisms.