Alpha power increases spontaneously during a neurofeedback session

Area of Science:

• Neuroscience
• Cognitive Science
• Psychophysiology

Background:

• Electroencephalographic neurofeedback (EEG-NF) is a technique using real-time EEG feedback to modulate brain activity.
• Alpha neurofeedback is particularly explored for cognitive enhancement and clinical applications, assuming it enables volitional brain rhythm regulation.

Purpose of the Study:

• To investigate whether alpha neurofeedback genuinely facilitates volitional control over brain rhythms or if observed effects stem from non-specific influences.
• To critically reassess the underlying mechanisms and efficacy of EEG-NF.

Main Methods:

• A preregistered, double-blind, sham-controlled study was conducted with healthy participants.
• Three groups were included: genuine EEG-NF, sham EEG-NF, and a passive control group.
• EEG data was analyzed to assess alpha power changes and other brain rhythms under different feedback conditions.

Main Results:

• A robust increase in alpha power was observed across all groups, irrespective of feedback veracity or engagement in self-regulation.
• Parallel increases in theta and sensorimotor rhythms indicated broadband, non-specific modulation.
• Feedback update frequency did not influence the observed alpha power increases.

Conclusions:

• The findings challenge the core assumption that EEG-NF enables volitional control of brain activity.
• Spontaneous, repetition-related processes appear to be the primary drivers of observed EEG changes, not specific volitional control.
• A critical reevaluation of EEG-NF efficacy and its mechanistic underpinnings is warranted.