As the body’s conductor, the brain, home to around 100 billion neurons, remains shrouded in mysteries, from its development and function to its remarkable adaptability. Central to this exploration, neurofeedback offers a powerful way to tap into the brain’s innate capacity to rewire itself by providing real-time insight into its neuronal signals. How does this therapy work, what equipment does it require and what are its applications? Join us as we unveil the secrets of neurofeedback and the innovative approach employed by Neuromind.
What is neurofeedback?
Definition of neurofeedback
Neurofeedback, also known as EEG biofeedback, is a non-invasive training method based on neurosciences. The principle involves recording the brain’s electrical activity from the scalp and translating these signals into immediate sensory feedback (auditory, visual or tactile). By observing brainwaves, users learn to reinforce or inhibit specific frequency bands associated with targeted mental states, such as relaxation or concentration.
Over successive sessions, this voluntary modulation of neuronal oscillations leverages neuroplasticity: the brain’s ability to form and consolidate new synaptic connections [1]. Neurofeedback is considered a therapy rather than a pharmacological treatment, as it does not rely on medication.
The story behind the technique
The first experiments in neurofeedback date back to the pioneering work of Dr Barry Sterman in the 1960s. In a study published in Brain Research in 1967, the researchers implanted electrodes on the scalps of cats to monitor their sensorimotor rhythm (SMR, 12-15 Hz) in real time.
Each time the felines increased the amplitude of these waves, a dispenser rewarded them with food. The animals quickly understood the subterfuge and learned to produce more SMR waves. This experiment revealed that brain activity can be modified by operant conditioning [2].
NASA later became interested in these protocols to address a critical issue: exposure to rocket fuel vapours was provoking epileptic seizures in some astronauts. When cats trained via neurofeedback were exposed to these vapours, only a minority experienced convulsions [3].
Building on these findings, Sterman adapted the method for human patients with epilepsy. Electrodes were placed on their scalps, and a green light signalled whenever SMR production increased. Remarkably, the participants experienced a roughly 65% reduction in seizure frequency. This clinical success paved the way for applying neurofeedback across various neurological and psychiatric pathologies [3].
Key modalities
While electroencephalography (EEG) remains the leading neurofeedback modality thanks to its millisecond-level temporal resolution, other techniques provide complementary insights:
– fNIRS (functional near-infrared spectroscopy) tracks variations in cerebral oxygenation to locate changes in cortical activity [4];
– HEG (hemoencephalography) and fMRI (functional magnetic resonance imaging) offer superior spatial resolution, although with less portability [5][6];
– peripheral measures such as electrodermal activity (EDA) and electrocardiography (ECG) enrich the feedback loop by indexing arousal and stress, while eye-tracking reveals attention fluctuations [7].
Neurofeedback: how does it work?
Capturing neural activity
In the different areas of the brain, nerve impulses are expressed rhythmically, like a pulse. EEG sensors placed on the scalp are able to identify these fluctuations and translate them into waves measured in hertz (Hz) [8].
Advanced signal-processing chains remove artefacts (muscle tension, eye blinks, etc.) and isolate key frequency bands:
– delta (from 0.5 to 4 Hz): broad, slow waves corresponding to a state of tranquillity and associated with deep sleep or intense meditation;
– theta (from 4 to 7 Hz): a state of relaxation in full wakefulness, light meditation that can go as far as drowsiness;
– alpha (from 8 to 12 Hz): a state of calm, feeling of well-being, creativity;
– beta (from 13 to 30 Hz): alertness and active concentration;
– sensorimotor rhythm (SMR, from 12 to 15 Hz): focused concentration prior to action;
– gamma (from 30 to 100 Hz): intense cognitive processing.
The user’s state is then determined by a set of quantitative and qualitative features extracted from those bands (time-frequency analysis, signal complexity metrics, measures of connectivity…).
From signal to feedback loop
At the heart of the biofeedback process lies a closed-loop system. Machine-learning algorithms trained on extensive datasets recognise wave patterns corresponding to the desired brain states [6].
When a user reaches a target state, the system rewards them by:
– displaying dynamic graphs or animations (e.g. a growing tree or a bar chart);
– changing LED light patterns (colour or brightness);
– advancing through a virtual environment;
– modulating background music tempo or instrumentation;
– warming or cooling small temperature pads;
– providing tactile feedback through wearable devices (e.g. vibration).
This operant conditioning gradually enhances the user’s ability to modulate their own brainwaves, capitalising on neuroplasticity and solidifying their brainwave modulation skills [5][9].
Common neurofeedback protocols
Neurofeedback protocols specify which brain-wave frequencies and scalp locations to train, and are chosen by professionals based on a prior quantitative EEG (qEEG) assessment or symptomatology [8]. Among the most widely employed are:
– SMR training (central/sensorimotor cortex): inhibits excessive theta (4-7 Hz) and high beta (20-30 Hz) while enhancing the sensorimotor rhythm (SMR). It promotes calm focus, stabilises motor control, and supports sleep regulation, particularly useful in ADHD and insomnia;
– alpha enhancement (posterior parietal cortex): often done with eyes closed, this protocol strengthens alpha waves while suppressing theta and high beta. It encourages relaxation, helps reduce anxiety, and improves sleep quality;
– alpha/theta training (parietal/occipital regions): rewards theta while maintaining or slightly reducing alpha, often in eyes-closed conditions. It induces deep relaxation, fosters creative states, and is commonly used in trauma recovery or addiction therapy;
-theta/beta ratio training (central or midline frontal cortex): reduces the theta/beta ratio by down-training theta and up-training low beta (15-18 Hz). It is particularly effective in improving attention and reducing impulsivity in individuals with ADHD;
– frontal alpha asymmetry training (left/right prefrontal cortex): used in mood regulation, this method corrects imbalances by decreasing alpha in the left hemisphere (F3) and increasing beta to support motivation and emotional resilience;
– deep relaxation protocol (theta + alpha, parietal/occipital regions): by enhancing both alpha and theta and suppressing high beta, this protocol evokes meditative states, supports emotional processing, and reduces stress.
Beyond raw band frequencies, advanced systems extract quantitative and qualitative features, such as:
– entropy (e.g. SampEn): though still emerging, these measures can detect subtle irregularities in neural dynamics. Often used for ADHD protocols, cognitive workload monitoring and consciousness assessment;
– functional connectivity (e.g. phase-locking value, coherence): assess synchronisation between brain regions rather than isolated oscillations, helping to retrain network-level patterns. Commonly applied in depression, schizophrenia or cognition protocols;
– source localisation (e.g. sLORETA): targets deep or distributed cortical generators in PTSD, ADHD or trauma-related conditions;
– machine learning features: enable personalised performance training via classifier-driven feedback;
– multimodal coupling, EEG-fNIRS or EEG-HRV based: refines feedback in stress and burnout interventions by integrating cerebral oxygenation or autonomic markers.
Each of these protocols uses auditory, visual or immersive feedback to guide the user toward optimal brainwave patterns. Over time, this learning process is reinforced through neuroplasticity, helping to establish long-lasting changes in brain function.
Equipment used during a session
A modern neurofeedback setup includes:
– EEG headset: up to 256 electrodes in some research configurations, available in dry, gel or saline formats;
– amplifier and signal processor: real-time artefact rejection and spectral analysis;
– feedback interface: computer screen, audio headset or immersive VR environment;
– optional sensors: EDA (emotional arousal), ECG (heart-rate patterns) and eye-tracking (visual attention) for a richer multimodal experience [4][6].
What neurofeedback is used for?
Mental health and neurological disorders
Neurofeedback is recognised as an effective complementary therapy for conditions such as attention deficit disorder with or without hyperactivity (ADHD), anxiety disorders, depression and post-traumatic stress disorder (PTSD):
– ADHD: meta-analyses reveal significant improvements in attention and behavioural regulation following neurofeedback training [10];
– anxiety and depression: alpha/theta and SMR protocols deliver lasting positive effects [11][12];
– PTSD: veterans undergoing alpha/theta training showed a reduction in their symptoms [13];
– comparative trials: studies comparing neurofeedback to cognitive behavioural therapy in ADHD report similar gains in executive function [14].
Cognitive enhancement and performance
Beyond clinical populations, neurofeedback is used by athletes, artists and professionals to sharpen their attention, strengthen their memory and achieve a state of “flow” more easily:
– upper-alpha training: linked to enhanced cognitive performance [15];
– cognitive modulation: confirmed as a valuable tool in a recent systematic review [16];
– performance optimisation: demonstrates faster reaction times, better decision-making and stress reduction in high-pressure scenarios [17];
– specialist domains: research by Dr Gruzelier highlights benefits for musicians, actors and sportspeople [18].
Wellness and stress management
Neurofeedback also enriches everyday well-being by alleviating stress, improving sleep and combating chronic fatigue:
– alpha/theta protocol: supports mindfulness practice by training users to reach states of deep relaxation [19];
– long-term integration: a neurophysiological theory suggests improved psychological integration and long-distance functional connectivity in the brain [20].
Are there any side effects to neurofeedback?
Neurofeedback is widely considered as a safe and non-invasive therapy. Some participants report transient side effects such as headaches, fatigue or slight irritability [21]. These symptoms occur during the first few sessions, as the brain adapts to new patterns.
However, the software adapts to the way the user’s individual neural patterns works and doesn’t impose anything on the body. Any side-effects encountered are always temporary and of low intensity. In fact, no long-term adverse effects have been documented.
Neuromind’s unique neurofeedback solution
Neuromind embodies a new generation of multimodal neurofeedback, combining electroencephalography (EEG), electrocardiography (ECG), electrodermal activity (EDA) and eye-tracking in an immersive virtual reality environment. This device trains and regulates attentional and emotional states through a non-invasive brain-machine interface (BCI).
The system is based on on-board sensors that measure the activity of the central nervous system (via EEG) and autonomic nervous system (via ECG and EDA) in real time. This data is then analysed using artificial intelligence algorithms to extract two proprietary emotional biomarkers:
– arousal, which measures the level of activation (from relaxation to hypervigilance);
– valence, which indicates the emotional tone (positive or negative).
Neuromind’s originality lies in its capacity for dynamic adaptation: the virtual environment adjusts in real time to the user’s emotional state. When the user reaches the target state, for example an optimal level of calm or concentration, the device reinforces this state by modifying the sound, visual or interactive elements of the virtual world. This closed feedback loop encourages reinforcement learning based on neuroplasticity.
Validated by promising results in terms of state anxiety reductions and heart-brain connectivity, our approach was presented at the Society for Neuroscience congress in 2024. Neuromind was also awarded a prize in the i-Nov competition as part of the France 2030 plan and selected for the IMPACT mental health 2024 program, confirming its potential as a leading digital healthcare solution.
Ready to explore Neuromind? Contact us today to arrange a demonstration and discover how our platform can transform your practice or research.
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[2] Sterman, M. B., Macdonald, L. R., & Stone, R. K. (1967). Biofeedback training of the sensorimotor EEG rhythm in cats and its effect on seizure susceptibility. Brain Research, 6(2), 369–382.
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