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Real-Time EEG Neurofeedback Using a Subject-Independent Classifier in Women With Depressive Symptoms
Sponsor: Pontificia Universidad Catolica de Chile
Summary
This completed feasibility study examined whether right-handed women aged 18-35 years with mild-to-moderate depressive symptoms could use real-time electroencephalography (EEG) neurofeedback based on a subject-independent classifier to regulate brain activity toward a classifier-defined reference pattern. Participants were randomly assigned to receive either classifier-contingent visual feedback with performance-contingent monetary rewards or noncontingent sham visual feedback with yoked monetary rewards. All participants completed five training sessions over approximately 3 weeks. The primary purpose was to determine whether overall classifier accuracy during training exceeded the theoretical 50% chance level. Changes in clinician-rated and self-reported depressive symptoms, associations between classifier performance and symptom change, EEG spatial patterns, and procedural tolerability were exploratory.
Official title: A Randomized, Double-blind Feasibility Study of a Subject-independent Classifier-based EEG Neurofeedback in Women With Depressive Symptoms
Key Details
Gender
FEMALE
Age Range
18 Years - 35 Years
Study Type
INTERVENTIONAL
Enrollment
20
Start Date
2019-01-04
Completion Date
2023-01-30
Last Updated
2026-09-11
Healthy Volunteers
No
Conditions
Interventions
Contingent Subject-Independent Classifier-Based EEG Neurofeedback
Five sessions were delivered on separate days over approximately 3 weeks. Each session comprised four 300-second runs separated by 1-3-minute rest intervals. Each run contained four 20-second positive autobiographical memory recall blocks and four 20-second motor imagery blocks. A pretrained Filter Bank Common Spatial Pattern-linear support vector machine classifier processed 28 EEG channels in real time. The visual thermometer rose or fell by one level according to whether each classifier output matched the instructed mental state. At the end of each run, participants viewed classifier accuracy and received a prespecified performance-contingent monetary reward.
Noncontingent Sham EEG Feedback With Yoked Rewards
Participants received the same five-session schedule, task structure, visual display, and scripted instructions as the experimental arm. Each thermometer update was a randomly determined one-level increase or decrease and was independent of EEG activity. Rewards followed the run-by-run sequence obtained by the experimental-arm participant with the highest total reward and were not contingent on the control participant's classifier performance.
Locations (1)
Laboratory for Brain-Machine Interfaces and Neuromodulation, Pontificia Universidad Católica de Chile
Santiago, RM, Chile