Spontaneous Modulation of Alpha Power During a Neurofeedback Session Without Instructions

Area of Science:

• Neuroscience
• Cognitive Science

Background:

• Electroencephalographic neurofeedback (EEG-NF) allows self-regulation of brain activity.
• Mechanisms of EEG modulation, especially alpha activity (8-12 Hz) upregulation, are not fully understood.
• Previous work suggested spontaneous alpha increases during passive neurofeedback-like tasks.

Purpose of the Study:

• To investigate the mechanisms of alpha activity upregulation during EEG-NF.
• To determine if alpha power increases are due to self-regulation or spontaneous dynamics.
• To evaluate the impact of feedback presence, frequency, and source on EEG features.

Main Methods:

• Thirty-two healthy adults participated in a study involving visual feedback (circle size) updated in real-time.
• Experimental conditions included feedback updated at 1, 5, or 10 Hz, alongside a control condition with fixed feedback.
• Participants were unaware of the feedback's nature or received no self-regulation instructions.

Main Results:

• Robust increases in alpha power were observed over time, irrespective of feedback presence, frequency, or source.
• Feedback parameters (presence, frequency, source) did not significantly influence the targeted EEG features.
• No significant differences in EEG features were found across control and experimental conditions.

Conclusions:

• Alpha EEG-NF upregulation might stem from spontaneous dynamics (e.g., time-on-task effects) rather than volitional self-regulation.
• The assumption that observed alpha increases indicate successful neurofeedback learning needs re-evaluation.
• Emphasizes the necessity of control conditions and accounting for non-specific effects in EEG-NF research.