Neurofeedback is a promising technique that allows people to voluntarily control their own brain activity with the goal of improving cognitive functions or relieving symptoms.
Key Facts:
- Neurofeedback provides real-time feedback on brain activity, allowing a person to learn to control activity in specific brain regions.
- It has shown clinical benefits for disorders like ADHD, anxiety, depression, addiction, and more.
- It can enhance cognitive skills like attention, perception, and confidence in healthy people.
- Effects rely on the brain’s lifelong ability to be shaped and reorganized.
Source: Revue Neurologique
What is Neurofeedback & How Does it Work?
Neurofeedback, also called brain biofeedback, is a method of teaching people to purposefully alter their own brain function by providing real-time information about activity in specific areas and networks.
For example, you may hear auditory feedback that reflects frequencies recorded over sensorimotor cortex, or see a visual meter that displays blood flow changes in anterior cingulate cortex.
The feedback gives insight into covert neurophysiological processes.
By learning associations between mental states and effects on the external signal, people can begin fine-tuning electrical rhythms or blood flow volumes through intentional cognitive acts.
Operant conditioning helps engraves these new patterns of activity.
With practice, specialized neuronal circuits can be strengthened or weakened, allowing neurofeedback training to have lingering behavioral effects.
The reinforcing nature of the feedback also activates brain regions involved in learning and motivation.
Protocols often involve 10-20 training sessions of around 30 minutes.
During this time, computer software processes neural imaging data (EEG, fMRI, etc) and translates relevant features into auditory tones or visual interfaces.
The feedback is presented in real-time with little delay.
Clinical Applications of Neurofeedback
Much research has explored neurofeedback therapies for psychiatric disorders with physiological underpinnings, including ADHD, anxiety, PTSD, addiction, and chronic pain.
By normalizing atypical neural signaling patterns, symptoms can sometimes be significantly reduced.
ADHD and Impulse Control
People with ADHD exhibit excessive slow wave (theta) EEG activity and insufficient fast wave (beta) activity during concentration tasks.
Neurofeedback that rewards increases in the beta/theta ratio has been associated with improved attention and impulse control.
Though less effective than stimulant medication, it avoids side effects and teaches self-regulation skills.
Additionally, training willful control over event-related potentials that reflect attentional preparation and impulse inhibition helps counter distraction and impulsive tendencies.
Many ADHD patients that undergo such protocols can better resist behavioral urges and sustain focus, reflected in normalized P300 brain waves.
Treating Anxiety and Depression
In depression, overweighting of right frontal alpha rhythms correlates with negative mood and rumination.
Self-adjusting this alpha asymmetry has led to mood improvements equivalent to antidepressant drugs.
Neurofeedback also holds promise for anxiety disorders like PTSD where symptoms seem mediated by abnormal neural oscillations.
By training more balanced alpha waves or greater activation in prefrontal regions involved in emotion regulation, the fight-flight reactions to traumatic memories can be prevented.
Patients report fewer flashbacks and less pronounced distress when recalling past trauma.
The technique may also benefit panic disorders, social phobia, OCD and generalized anxiety through intentionally shifting brain rhythms and metabolism supporting maladaptive thought patterns.
Overcoming Addictions
The craving signals underlying substance dependence and addiction originate from overactive reward circuits, especially nucleus accumbens and orbitofrontal cortex.
Neurofeedback targeting hypoactivation in these areas decreases cravings and consumption as self-control is strengthened.
Even gambling addictions have diminished from this approach by reducing urges and excitement linked to financial risk-taking.
Similar mechanisms may help overeaters resist the pull of highly appetizing foods.
When applied alongside cognitive and behavior therapies, newly trained signaling patterns help reinforce adaptive behaviors.
Chronic Pain Management
By providing feedback from brain areas parsing pain intensity like the rostral anterior cingulate cortex, patients can progressively gain control over endogenous opioid pathways and diminish their perceived discomfort.
Fibromyalgia, back pain, and postsurgical pain have all been attenuated through such methods.
Neurofeedback for Cognitive Enhancement?
Beyond clinical domains, neurofeedback can also enhance functions like attention, perception, and cognition in normal healthy adults with no known disorders.
Some of the most intriguing research focuses on training control over the information decoded from multivoxel fMRI activity patterns.
Rather than simply displaying levels of activation in a single brain area, advanced machine learning algorithms can determine specific mental states on a moment-to-moment basis from distributed activity.
For example, one study used decoded feedback from early visual areas to allow participants to voluntarily control the subjective vividness and intensity of illusory colors.
The achromatic greyscale patterns took on a pulsing quality and illusory saturated hues like red or green based entirely on top-down signals driven by the neurofeedback.
Likewise, multivariate decoders trained to distinguish attentional spotlight focus on faces versus places enabled participants to regulate their concentration through reinforcements at the cognitive rather than perceptual level.
By iteratively practicing control over classifier outputs corresponding to transient mind states, executive control networks can be finely tuned in a use-dependent manner.
Transfer tests reveal far superior attention regulation abilities even in unrelated tasks.
Such decoded neurofeedback may provide a paradigm shift enabling far more selective remapping of complex mental functions supported by distributed neural populations.
Traditional neurofeedback relying instead on activation magnitudes is restricted to simple sensory or motor processes with defined anatomical substrates.
How Neurofeedback Changes the Brain
The behavioral improvements and long-lasting therapeutic gains induced by neurofeedback training originate from neuromodulatory effects and brain reorganization at microscopic and macroscopic levels.
Firstly, the rewarding feedback itself works in an analogous manner to other reinforcement learning.
There is significant overlap between the brain networks mediating operant conditioning of neurons and those regulating behavior during rewarding games or financial incentives.
Structures like the basal ganglia and frontal cortex show greater metabolic activity during neurofeedback.
Furthermore, exercising intentional control over localized brain regions drives Hebbian plastic processes that enhance communication efficiency between neural populations underlying the target ability or state.
Connections become more synchronized. This manifests as strengthened intra- and inter-regional functional connectivity along relevant larger-scale networks.
Finally, more permanent neuronal changes are reflected in gray matter thickening across associated cortices as synapses expand dendritic branching to consolidate enhanced signaling.
White matter integrity and myelination also increases within connecting tracts.
For example, executive control networks show robust architectural changes after just a single 30-minute EEG neurofeedback session for some individuals.
Of course, the specific locations of these plastic effects depend greatly on which aspects of cognition or behavior are being trained.
But the mechanics remain quite consistent regardless of the targeted mental process.
Again relying on operant conditioning paradigms, brain physiology is shaped to enable improved behavioral outcomes.
Limitations & Open Questions for Neurofeedback Research
Many intriguing findings support neurofeedback as a potent approach for investigating brain-behavior relationships and developing personalized non-pharmacological clinical treatments with minimal side effects.
However, several outstanding issues remain.
The durability of behavioral improvements and brain changes following short periods of training requires further characterization across patient groups and cognitive domains.
Do structural brain alterations enabling enhanced functions persist for months after the final therapy session? Are functional gains evident in real-world untrained contexts?
Carefully controlled studies must better account for confounding variables like subject expectation biases or interactions with a therapist.
Pure placebo neurofeedback groups are essential to confirm that feedback itself specifically catalyzes improvements rather than simply motivating patients.
Additionally, about 25% of participants prove incapable of purposefully modulating their own neural signals and show negligible progress in response to neurofeedback methods.
Predicting who will succeed or fail at self-regulation based on individual differences may allow screening or adapted personalized protocols.
Lastly, innovative processing methods for extracting maximally useful information from noninvasive imaging data will enable increasingly specific targeting of finely-grained cognitive operations.
Though still lacking the precision of intracranial recordings, the latest multivariate pattern analyses and decoding algorithms allow aspects like spatial attention and emotions to be tracked with relatively high fidelity in EEG and fMRI data.
Future neurofeedback systems can leverage these advancements to selectively remodel key subfunctions underlying complex behaviors.
In closing, while some open questions remain about optimizing techniques and better understanding mechanisms, neurofeedback is an exceptionally promising avenue for enhancing function or treating mental disorders by training individuals to reprogram their own brain physiology through closed feedback loops.
Ongoing technical and computational innovations will undoubtedly make such systems even more practical and effective in the coming years.
References
- Study: Neurofeedback for cognitive enhancement and intervention and brain plasticity
- Authors: Loriette et al. (2021)
