Science
The Science of Neurofeedback
Neurofeedback has been studied for decades, but results vary by protocol, population, study design, and outcome. This page explains the basic mechanism, what Narbis feedback glasses do, and what current research can—and cannot—support.
Neurofeedback, in plain language
What is neurofeedback?
Neurofeedback is a form of biofeedback. Sensors measure a selected brain-activity signal, software translates that signal into a metric, and the user receives immediate feedback—such as a visual, sound, or changing lens tint. The feedback is intended to help the user notice and practice a target state.
Neurofeedback is non-invasive: the sensors record activity and do not send electrical stimulation into the brain. Different systems measure different signals and use different protocols, so findings from one protocol or device should not automatically be assumed to apply to another.
How does the feedback loop work?
The basic learning model is operant conditioning. When the measured signal meets the protocol's target, the system provides a reward or removes a cue. With repeated training, some users may learn to influence the measured pattern or the behavior associated with it.
- A sensor records a selected physiological signal.
- An algorithm compares that signal with the protocol's target.
- The user receives immediate feedback and practices responding to it.
A plausible feedback mechanism does not by itself prove a clinical benefit. Clinical questions require controlled studies with appropriate comparison groups, blinded outcome measures where possible, and results that can be replicated.
What is specific to the Narbis approach?
Narbis places the feedback in electrochromic lenses. In the home EEG system, the glasses use measured EEG and an engagement-index approach to change lens tint. In supported integrations, Edge glasses can serve as the visual feedback display for a compatible EEG system. The product pages explain the hardware and app requirements for each configuration.
NASA did not invent neurofeedback. NASA Langley researcher Alan Pope developed an engagement index for pilot-attention research in the 1990s. Domenic and Devon Greco later licensed aspects of that work for an earlier company, and Narbis subsequently applied the concept to feedback glasses. Read NASA's Narbis Spinoff feature →
What does the broader evidence show?
Neurofeedback has a long research history, but the evidence is not uniform. Studies differ in protocol, training dose, comparison condition, participant population, outcome measure, and who rated the outcome. Reviews have therefore reached different conclusions, and findings from the general field are not proof of outcomes for a specific Narbis product.
Some earlier reviews reported sustained or protocol-specific benefits. More recent analyses using stricter outcome criteria have been less favorable. The responsible conclusion is that results are mixed and that a consumer should not treat neurofeedback as a proven substitute for established medical care.
What does current ADHD research say?
A 2025 systematic review and meta-analysis in JAMA Psychiatry included 38 randomized clinical trials with 2,472 participants. On probably blinded ratings, neurofeedback did not produce a meaningful group-level improvement in overall ADHD symptoms. The authors did find small effects in analyses limited to established standard protocols, and processing speed was the only one of five neuropsychological outcomes with a small significant improvement.
The review concluded that the overall evidence did not support neurofeedback as a stand-alone ADHD treatment. That conclusion is more cautious than several earlier reviews and illustrates why protocol details and study quality matter. Read the 2025 review on PubMed →
Discuss it with a qualified clinician who knows your history and current treatment plan. Do not start, stop, or change medication or other treatment based on this website.
Sources, product evidence, and limitations
- Westwood SJ, et al. Neurofeedback for Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis. JAMA Psychiatry. 2025;82(2):118–129. DOI
- Van Doren J, et al. Sustained effects of neurofeedback in ADHD: a systematic review and meta-analysis. European Child & Adolescent Psychiatry. 2019;28:293–305. PubMed
- NASA Spinoff. Smart Glasses Focus Attention with NASA Neurofeedback Technology. Updated June 22, 2026. NASA
This page summarizes general background and selected research; it is not a systematic review and does not establish that a Narbis product produces a clinical outcome. Narbis products are wellness tools and are not intended to diagnose, treat, cure, or prevent disease.
What other questions do you have?
Email info@narbis.com with product, compatibility, or research questions. For individualized medical advice, contact a qualified healthcare professional.