What are the top brainwave kits of 2024?

Neuralink recently demonstrated the successful use of its N1 chip — a brain-computer interface (BCI) — in the first human participant. This 64-probe device has 1,024 electrodes and can provide data on how the human brain works. The electrodes connect directly with an individual’s neurons, providing detailed insight into how brainwave signals operate. However, this neurotechnology is costly and physically invasive.

Alternatively, several other non-invasive methods are more accessible and safer, and they also provide a look into the human brain. In this article, we’ll discuss these methods of brain-computer interfaces, focusing on the EEG headsets in more detail, which are the most accessible brain-computer interfaces.

Non-invasive methods
The non-invasive methods for studying the human brain are nonsurgical, so they’re much safer and less costly. Currently, the most common method is Electroencephalography (EEG). Most other methods are typically only used in research settings. Let’s discuss these below.

Electroencephalography (EEG) is a non-invasive technique to measure the electrical activity produced by the brain. The brain is a sophisticated network of neurons that continuously exchange electrical impulses with one another. These activities produce rhythmic patterns called brainwaves. In EEG, electrodes are applied to the scalp to detect these brainwaves.

The brain-computer interface uses electrical activity to deduce the user’s intent or mental state. EEG is the most accessible method for monitoring brain activity, and headsets are widely available for various niche applications.

Functional Magnetic Resonance Imaging (fMRI) is a powerful neuroimaging technique that measures brain activity indirectly by detecting changes in blood flow and oxygenation. It’s based on the principle of neurovascular coupling, which is the relationship between neural activity and blood flow. It uses a large scanner for detection. When a particular brain region becomes active, it requires more oxygenated blood to support the increased metabolic demands of the neurons. This increased blood flow leads to changes in oxygenated and deoxygenated hemoglobin concentration.

An fMRI, with its ability to detect the blood flow and levels of oxygenation, provides a wealth of detailed information about which brain regions are active during specific tasks or mental states. This technology, while accessible only in a hospital or research facility, offers a fascinating glimpse into the inner workings of the brain.

An individual lies inside a large, cylindrical magnet while having an fMRI scan. The scanner uses radio waves in conjunction with a powerful magnetic field to identify the activity of hydrogen atoms within the body — namely in the water molecules that make up blood. fMRI uses the blood-oxygen-level dependent (BOLD) signal as its principal measure. This signal represents variations in the blood’s oxygenated-to-deoxygenated hemoglobin ratio in reaction to brain activity.

Typically, participants engage in specific cognitive tasks (such as reading, listening, and problem-solving) while in the scanner so researchers can determine which parts of the brain are involved in carrying out a given task by comparing brain activity during the task to a baseline.

Generally, researchers study the intrinsic functional connectivity between different brain regions and networks, getting insights into the brain’s organization and dynamics. For example, an fMRI is used to study various cognitive functions such as memory, attention, memory, emotion, and decision-making. It also helps locate brain lesions, map functional areas of the brain before surgery, and investigate neurological and psychiatric disorders.

However, this method has two significant drawbacks. Its temporal resolution is relatively slow compared to other techniques like an EEG. Additionally, the analysis of fMRI data requires sophisticated statistical methods to account for noise, motion artifacts, and individual differences.

Near-Infrared Spectroscopy (NIRS) is a neuroimaging technique based on the same principle as fMRI. It measures changes in blood oxygenation and blood volume in the brain, but it uses near-infrared light. Although biological tissues, such as the skull, can be penetrated by near-infrared light, oxygenated and deoxygenated hemoglobin absorb the light differently. The NIRS picks up these variations in hemoglobin content to deduce brain activity.

This method uses optodes, which are light-emitting diodes (LEDs) and photodetectors. The optodes are placed on an individual’s scalp to transmit and detect near-infrared light. The optodes are arranged in pairs of LEDs and photodetectors. The LEDs transmit light into the tissue, while the photodetectors detect light after it’s traveled through the tissue. The source optode emits near-infrared light penetrating the brain tissue, skull, and scalp. The blood’s hemoglobin molecules absorb some of this light, scattering the rest so the adjacent detector optode can detect it.

NIRS can determine the amount of oxygenated and deoxygenated hemoglobin in the underlying brain tissue by calculating the intensity of the light detected. Algorithms that distinguish between the contributions of hemoglobin and compute variations in their concentrations over time are used to examine the data from optodes. These alterations are frequently shown as variations in the concentration of oxygenated hemoglobin — sometimes referred to as hemodynamic responses or oxygenation changes.

NIRS is far more portable and reasonably priced than other neuroimaging methods. However, it can only assess changes in hemoglobin concentration in the cortex’s superficial layers and has a reduced spatial resolution. Additionally, motion artifacts, skin pigmentation, and the thickness of the scalp and skull can impact NIRS readings.

Magnetoencephalography (MEG) is an advanced neuroimaging technique based on the principle of electromagnetic induction. Tiny electrical currents are produced by activated brain neurons, which then create small magnetic fields.

In this technique, an array of highly sensitive sensors that detect weak magnetic fields produced by neural activity is placed in a helmet-like system on the participant’s head. These sensors are cooled down to extremely low temperatures with the help of liquid helium for superconductivity. That is why they are called superconducting quantum interference devices (SQUIDs).

The person in the MEG scanner might be asked to sleep soundly or engage in cognitive tasks. With millisecond precision, the sensors record cerebral activity dynamics by sensing the brain’s magnetic fields in real-time. The recorded data is analyzed to localize the sources of neural activity in the brain.

This technique offers high temporal resolution of milliseconds, is non-invasive, and directly measures neural activities. However, it’s costly and less sensitive to deep brain structures and neural sources near the skull. For better accuracy, the technique is often combined with an fMRI and EEG.

Event-related Potentials (ERPs) detect changes in the electrical voltage of the brain using EEG or MEG in response to particular stimuli, such as a flashing light. Although it offers high temporal resolution, data analysis requires specific tools and knowledge. The brain activities measured can be sensory, including visual, auditory, motor, or cognitive, like memory and attention.

When recording the impulses, the timing of the events is precisely controlled, so the recorded EEG/MEG data is time-locked to the event trigger. The signals are averaged over multiple trials to isolate specific ERP components from the background brain activity and noise.

The components are identified based on latency (i.e., time after stimulus onset) and scalp topography (i.e., signal distribution across electrode sites). Some of the common ERP components are P1/N1, N2/P3 and N400/P600. P1/N1 is an ERP component corresponding to sensory events. N2/P3 are ERP components related to cognitive functions like memory, attention, and decision-making. N400/P600 is related to language processing and semantic integration.

Electrocorticography (ECoG) is a minimally invasive neuroimaging technique. Similar in principle to EEG, ECoG involves the direct placement of electrodes on the brain’s surface instead of the scalp. The electrodes are implanted into the specific regions of the brain by a minimally invasive neurosurgery. The placement of the electrodes could be permanent or temporary for monitoring.

The signals captured by the electrodes are amplified and transmitted to a recording system. These signals provide information about the synchronized activity of hundreds to millions of neurons in the underlying cortical tissue.

ECoG offers a more focused and detailed picture of brain activity than an ECG. The method is often applied to the treatment of epilepsy, brain tumors, and other neurological conditions.

How EEG headsets work
Electroencephalography (EEG) is the most common non-invasive method for monitoring brain activity, which is recorded with an EEG headset. Typically, the headset contains multiple electrodes positioned strategically on the scalp according to the 10-20 system. The electrodes detect weak brain impulses and transmit them to a machine, where the signals are amplified, filtered, and reorganized for analysis. The signals are then displayed on a screen or printed as a waveform.

Different brainwave signals are related to different states of the mind. These signals are often classified as Alpha waves (related to relaxed wakefulness), Beta waves (related to alertness and attention), Theta waves (related to meditation and drowsiness), and Delta waves (related to deep sleep).

EEG is useful for functional mapping of the brain. It can identify areas active during specific tasks or mental states, which is useful in developing brain-computer interfaces. EEG is also helpful for biofeedback therapy and treatment of neurological disorders like epilepsy, seizures, and sleep disorders.

While EEG is a valuable tool, it does have limitations. Its spatial resolution is limited, and interpreting brainwaves can be complex due to factors such as age and mental state. However, despite these challenges, EEG remains the most affordable and suitable non-invasive method for brain-computer interfaces.

Brainwave kits
A brainwave kit usually consists of an EEG headset and software. The headset is worn on the head and connects with the software on a computer or mobile via Bluetooth. The headset measures the electrical signals of the brain (brainwaves) and transmits the raw data to the software. The electrodes in the headset are positioned according to the international 10-20 system.

The international 10-20 system is a standard system for placing electrodes in an EEG headset so that the outputs of different EEG headsets are comparable. In a 10-20 system, different brain regions are indicated by letters, such as ‘F’ for Frontal, ‘C’ for Central, ‘T’ for Temporal, ‘P’ for Parietal, and ‘O’ for Occipital. The letter ‘Z’ indicates the midline electrodes. Odd numbers indicate the left hemisphere, and even numbers the right hemisphere.

The anatomical landmarks like the nasion (bridge of the nose), inion (bony bump at the back of the head), and preauricular points (near the ears) are used as reference points on the head. The electrodes are positioned at specific percentages, such as 10 or 20% of the distance between the landmarks and standardized lines. This allows for the consistent placement of electrodes irrespective of different head sizes.

The software runs on a computer or through a smartphone. It translates the raw EEG data from the headset into meaningful insights. The software’s output can be a visual representation of the brainwaves, brainwave classification, or determination of the mental state based on detected brainwaves. The software may also contain a game or application run by mental commands or manipulation.

The top kits
Some of the most popular brainwave kits available are as follows.

1. Muse S headband is a popular EEG headset that is used for various purposes. It measures brainwave signals and provides real-time feedback through its companion app. For instance, the Muse S provides audio cues for enhancing meditation. It can also track breathing patterns, body movements, and heart rate, which is useful in guiding through meditation. The users can view brainwave patterns as graphs on the companion app. The band has sleep-tracking capabilities and can provide insights into sleep quality, cycles, and sleep. The band is also valuable for focus training.

2. NeuroSky MindWave Mobile 2 is an affordable, consumer-grade EEG headset for several activities. It can be used for real-time visualization of brainwaves, guided meditation, interactive brain-training games, and educational applications to improve cognitive abilities. The headset provides real-time transmission of brainwave data via Bluetooth. It also features tools and programming interfaces to build custom apps that run with the help of brainwaves.

3. Emotiv Epoc X is a high-end EEG headset for developers and researchers. It features 32 electrodes strategically placed to provide a comprehensive coverage of brainwave data. The electrodes have exceptional spatial resolution and high signal quality. The headset’s companion app, EmotivPRO, offers a suite for recording EEG data, visualization of brainwaves, and brainwave analysis. The advanced software features include statistical analysis tools, artifact rejection, and event tagging.

The headset also comes with a software development kit, EmotivBCI, useful for creating custom brain-computer interfaces. The SDK can access the raw EEG data, providing signal processing tools and machine learning algorithms for custom BCI applications. The headset helps with studying brain activities during specific tasks, virtual reality, immersive gaming, and enabling assistive technologies for those with disabilities.

4. Neurable offers EEG headsets specially designed for gaming, virtual reality, and entertainment. The headset monitors and interprets brain activity in real time, allowing users to interact with virtual and augmented reality environments using only their thoughts. The headset contains a few dry EEG sensors integrated within the ear cups and is useful for interactive gaming, virtual reality, and focus training.

5. Mindrider is designed to understand mental states while cycling. The headset monitors brain activity and maps it onto a visual representation of a user’s bike ride, offering insights into their cognitive and emotional experiences during their ride. The headset can also be used for meditation and relaxation.

6. Flow Neuroscience Flow Headset is a high-end, medical-grade EEG headset used to treat depression through a non-invasive method called transcranial direct current stimulation (tDCS). The electrodes are arranged in a specific configuration that targets the left dorsolateral prefrontal cortex (DLPFC) or other brain regions associated with depression. The headset can also be used for meditation, relaxation, and adjunctive therapy.

7. Dreem 2 tracks brain activity during sleep, providing insights into sleep stages, patterns, and quality to improve overall sleep and well-being. The headset offers sleep metrics, such as the time spent in different sleep stages (light, deep, REM), sleep efficiency, total sleep time, and sleep disruptions. It also offers neurofeedback through personalized audio cues or interventions for better sleeping. It also features a smart alarm that wakes the user according to their sleeping pattern. Users can track their sleep progress on the companion app, set sleep goals, and receive personalized tips for better sleeping.

8. Braintap Pro Plus monitors brainwave activity and delivers visual and auditory stimulation for deep relaxation, pain relief, sleep improvement, and focus training. It uses AVE technology, which synchronizes visual and aural inputs to affect brainwave patterns and create desired emotional states. The headset stimulates the brain to promote relaxation, focus, and other desired effects by delivering coordinated light pulses and sound frequencies.

Additionally, BrainTap Pro Plus offers audiovisual sessions to address particular aspects of well-being, including mood enhancement, stress reduction, improved sleep, and cognitive performance. Typically, these sessions include synchronized light and music patterns, guided meditations, visualizations, affirmations, and relaxation techniques. The sessions can also be customized according to personal preferences. The headset incorporates binaural beats and isochronic tones for meditation and relaxation.

9. Interaxon Muse is designed for meditation, deep relaxation, and sleep tracking. It also features several brain health challenges and exercises and can be used for focus training, stress management, and sleep improvement.

10. MindDoc is a medical-grade EEG headset that can offer suggested diagnoses and treatments for mental health conditions. It provides real-time brainwave monitoring and features sensors to track stress levels and emotional states. The headgear is capable of measuring physiological indicators like heart rate variability and skin conductance to gauge the user’s stress response. The headset is only available to healthcare professionals.

Applications
EEG headsets are helpful for monitoring brainwaves and studying brain function, cognition, and the effects of various stimuli on brain activity. These devices are necessary for developing brain-computer interfaces and BCI applications, such as controlling an object or a robotic limb via one’s thoughts and brain signals.

Several EEG headsets are designed for meditation, deep relaxation, sleep improvement, and stress management. They can support focus training and improved cognitive skills. Other applications include mind-controlled gaming, interactive experiences in virtual reality, augmented reality, and other mind-controlled applications.