Background
Academic anxiety is a major psychological concern among adolescents and has consistently been associated with impaired executive functioning, attentional control, emotional regulation, autonomic imbalance, and reduced creative cognition. Neurophysiological evidence indicates that these impairments are accompanied by dysregulated cortical alpha oscillations and reduced parasympathetic nervous system activity. Neurofeedback enables individuals to voluntarily regulate neural oscillatory activity through real-time electroencephalographic feedback, whereas audiovisual entrainment facilitates neural synchronization using rhythmic photic stimulation and binaural auditory stimulation. Despite encouraging evidence supporting each intervention independently, limited research has investigated their integration within an adaptive closed-loop neurofeedback architecture capable of delivering individualized reinforcement based on ongoing neural activity.
Objectives
The primary objective of this study is to determine whether an Audiovisual Entrainment Neurofeedback (AVE-NFB) system produces greater increases in resting-state absolute alpha-band power than isolated neurofeedback, isolated audiovisual entrainment, or sham intervention.
Secondary objectives are to evaluate changes in academic anxiety, autonomic nervous system regulation, divergent thinking, and the durability of treatment effects during one-week and one-month follow-up assessments.
Study Design
This study is a multicenter, four-arm, parallel-group, randomized controlled trial involving 120 participants recruited from two senior high school centers. Participants will be randomly assigned to one of four intervention groups:
Combined AVE-Neurofeedback Neurofeedback Only Audiovisual Entrainment Only Sham Control
Each participant will complete six intervention sessions across approximately six weeks.
Outcome assessments will be conducted at:
Baseline (Week 0) Immediately Post-intervention (Week 6) One-week Follow-up (Week 7) One-month Follow-up (Week 10) Closed-Loop Neurofeedback Mechanism
The Audiovisual Entrainment Neurofeedback (AVE-NFB) employs a fully adaptive closed-loop brain-computer interface integrating real-time EEG monitoring with synchronized audiovisual entrainment.
EEG signals are continuously acquired using the Muse S Athena wearable EEG headset at a sampling frequency of 256 Hz from four dry electrodes positioned at AF7, AF8, TP9, and TP10. Each intervention session begins with a standardized 5-minute calibration period consisting of 3 minutes of eyes-closed resting state followed by 2 minutes of eyes-open resting state. Calibration data are used to establish each participant's individualized resting absolute alpha-band activity (8-12 Hz).
During neurofeedback training, EEG signals undergo automated quality control, including artifact detection for eye blinks, excessive movement, and poor electrode contact. Only artifact-free epochs are processed for online estimation of absolute alpha-band power using short overlapping analysis windows.
The individualized reinforcement threshold is initialized at 110% of the participant's median resting absolute alpha power obtained during calibration. Throughout each training session, this threshold is dynamically adjusted by a physiological controller driven by rolling Heart Rate Variability (RMSSD) estimates. Positive reinforcement is delivered only when alpha power remains continuously above this adaptive threshold for at least 2 consecutive seconds while signal quality satisfies predefined artifact acceptance criteria.
Successful threshold attainment automatically activates synchronized audiovisual reinforcement consisting of:
Alpha-frequency rhythmic photic stimulation, Binaural beat auditory stimulation centered within the alpha range, Non-directive relaxation guidance, Continuous visual performance feedback.
Whenever alpha activity decreases below the reinforcement threshold or excessive artifacts are detected, audiovisual reinforcement is immediately attenuated or suspended until stable neural activity resumes. This adaptive reinforcement paradigm is designed to strengthen voluntary alpha self-regulation through operant conditioning rather than passive sensory stimulation.
Throughout each session, the system automatically records continuous EEG signals, artifact events, individualized threshold values, reinforcement activation duration, cumulative reinforcement time, session performance indices, and event timestamps for subsequent offline verification and statistical analysis.
Outcome Measures Primary Outcome
Resting-State Absolute Alpha Power (8-12 Hz) measured using the Muse S Athena wearable EEG headset.
Secondary Outcomes Academic anxiety assessed using the Spielberger Test Anxiety Inventory (TAI). Autonomic nervous system regulation assessed using Heart Rate Variability (RMSSD).
Divergent thinking assessed using the Alternative Uses Task (AUT), including fluency, flexibility, originality, and elaboration scores.
Statistical Analysis
Longitudinal repeated-measures data will be analyzed using Linear Mixed-Effects Models (LMM). Treatment group, assessment time, and the group-by-time interaction will be specified as fixed effects, whereas participant-specific random intercepts will account for within-subject dependency. School center, circadian assessment phase, and intervention session timing will be incorporated as predefined covariates. The LMM framework was selected because it appropriately accommodates repeated measurements, multicenter clustering, and incomplete follow-up observations under the missing-at-random assumption while preserving statistical efficiency.
Expected Significance
This study is expected to provide rigorous evidence regarding the efficacy of adaptive closed-loop multisensory neurofeedback for improving cortical alpha self-regulation, reducing academic anxiety, enhancing autonomic nervous system function, and promoting divergent thinking among adolescents. The findings may contribute to the development of scalable, neuroscience-based, non-pharmacological interventions for school mental health and cognitive enhancement.
