NEUROSKY HOME USE DEVICE FOR NEUROFEEDBACK

NeuroSky technology

NeuroSky technology allows low-cost EEG-linked research and products by using inexpensive dry sensors; older EEGs require the application of a conductive gel between the sensors and the head. The systems also include built-in electrical “noise” reduction software/hardware, and utilize embedded (chip-level) solutions for signal processing and output. The significant advantage of the dry sensor is the time it takes to set up. Traditional gel-based EEGs can take up to 30 minutes to acquire data, while the NeuroSky headsets are ready to go in seconds. The disadvantage of the dry sensor electrodes is increased impedance of the sensor’s contact with the scalp. This can cause low-amplitude signals not to be fully represented in the acquired data.

The headset has a ThinkGear ASIC Module (TGAM) chip that preprocesses the data within the headset itself. The eSense Meters (Attention and Meditation) are calculated on the ThinkGear chip.

ThinkGear Measurement Technology

NeuroSky developed a ThinkGear measurement technology to calculate the Power Spectrum Density (PSD) using a 512 samples per second sampling frequency and the eSense Attention meter algorithm to indicate the intensity of attention during intense concentration. The device amplifies and digitizes the voltage difference (to achieve better common-mode rejection) between a single dry sensor on the forehead and a reference on the ear. Analog and digital, low and high-pass filters the 1-50 Hz brain signal. The signal is analyzed in the time domain to detect and correct noise each second, and a standard FFT is performed. 

Finally, the signal is rechecked for noise and artifacts in the frequency domain to get brainwave strengths and eSense Attention and Meditation values. The eSense algorithm is dynamically learning, so ThinkGear sensors can operate on a wide range of individuals and under a wide range of personal and environmental conditions. NeuroSky’s EEG biosensor digitizes and amplifies raw analog brain signals to deliver concise inputs to games, toys, and devices running health and wellness, educational, and research applications.

The equipment that is the contemporary interior of every NeuroSky product allows a device to integrate with the user’s brainwaves. It consists of the sensor, which touches the user’s forehead, the reference and junction points presented in the ear clip, and the onboard chip that operates all of the data. The ThinkGear chip calculates both the dominant brainwaves and the eSense Meters (Attention and Meditation).

eSense

eSense is NeuroSky’s quick-fix algorithm for distinguishing mental states. To compute eSense, the NeuroSky ThinkGear technology fleshes out the raw brainwave signal and removes the ambient noise and muscle movement. The eSense algorithm is then applied to the remaining signal, resulting in the elucidated eSense meter values.

eSense Meter

Technical Description: For each different type of eSense, i.e., the Attention and Meditation meter values are described on the respective eSense scale of 1 to 100. A value of 40 to 60 at any given time is considered “neutral”. It is similar in notion to “baselines. A value across 60 to 80 is considered “slightly elevated”, and may be interpreted as levels of eSense values may be higher than normal for a given person. Values across 80 to 100 are considered “elevated”, denoting they are strongly expressive of heightened levels of that eSense. Similarly, on the other end, a value across 20 to 40 indicates “reduced” levels of the eSense, while a value across 1 to 20 indicates “strongly lowered” levels of the eSense.

Attention eSense

The eSense Meter algorithm specifies the strength of a user’s level of mental “attention” or “focus”, which occurs during extreme concentration and directed (but stable) mental activity. The meter value ranges from 0 to 100. The attention level increases when a user focuses on a single thought or an external object, and decreases when distracted. Users can observe their ability to concentrate using the algorithm. In educational settings, attention to lesson plans can be tracked to measure their effectiveness in engaging students. Attention has been used in gaming to create “push” control over virtual objects. Lack of concentration, wandering thoughts, Distractions, or anxiety may decrease the Attention meter level.

Meditation eSense

The eSense Meditation meter specifies the user’s mental “relaxation” or “calmness” level. The value ranges from 0 to 100, and increases when users relax their minds and decreases when they are uneasy or stressed. The Meditation Meter quantifies the ability to find an inner state of mindfulness. It can thus help users learn how to self-correct and find inner balance to overcome the stresses of everyday life. 

The algorithm is also used in a variety of game-design controls. Meditation measures a person’s mental states, not physical states, so relaxing all body muscles may not quickly result in an enhanced Meditation level. Nevertheless, in most everyday situations, relaxing the body frequently helps the mind relax. Meditation is associated with decreasing activity by the active mental processes in the brain. It has been observed that closing the eyes is often an effective method for increasing the Meditation meter level. Distractions, anxiety, sensory stimuli, and wandering thoughts may lower the Meditation meter levels.

Blink Detection

The Blink Detection algorithm signals a user’s blinks. A higher number indicates a “stronger” blink, while a smaller number indicates a “lighter” or “weaker” blink. The frequency of blinking is often correlated with nervousness or fatigue. Eye blinks are akin to a standard on/off binary system and, therefore, are valuable for controls that require definitive responses. For instance, in communication applications, one blink means no, and two means yes, giving individuals with special needs a simple communication method.

Mental Effort

The Mental Effort algorithm measures the mental workload while performing a task. The harder a user’s brain works on a task, the higher the value. The algorithm works well with physical (e.g., drawing) and mental (e.g., reciting) tasks. It can be used for continuous real-time tracking and between-trial comparisons to measure the effects of multi-tasking, workload variability, and more. The algorithm can track the effects of diverse cognitive loads on the ability to learn and provide feedback for user self-improvement.

Familiarity

The Familiarity algorithm tracks learning processes to measure the relative level of understanding, learning, or comfort with a task. It measures the subconscious knowledge of procedural (motor) and mental tasks. Sometimes, it reflects how well a user does with the task. By observing trends, users can better understand and assess their learning process. It can be applied to physical tasks (e.g., drawing) or mental (e.g., recitation), and enable data-tracking assessments to gauge learning status.

Appreciation

The Appreciation algorithm measures a subject’s enjoyment or appreciation of an external audiovisual stimulus. It allows moment-by-moment emotion detection. In marketing applications, it can track and understand a user’s level of appreciation, providing insights and strategic direction for marketing efforts.

Emotional Spectrum

The emotional spectrum measures emotional activity’s intensity (low-high) and pleasantness (pleasant/unpleasant). Pleasant/Unpleasant identifies whether a user has a pleasant or unpleasant emotion. Pleasant emotions could be happy, serene, relaxed, etc. Unpleasant emotions could be anger, disgust, depression, etc. Intensity measures how strong a user’s emotions are in real time. The emotion could be happy, angry, calm, or any other emotion. There are four eTensity levels: Very Weak, Weak, Strong, and Very Strong.

Cognitive Preparedness

Cognitive Preparedness measures the brain’s capacity for optimal cognitive performance on a relatively complex task, or, in other words, the brain’s capacity for higher-level cognitive functions.

Creativity

Creativity measures the brainwave activities underlying creative cognition. The higher the creativity value, the stronger the brainwave activities promote innovative and creative thinking.

Alertness

Alertness measures a user’s current alertness or vigilance level. A high alertness value indicates a state of focus, while a low value represents a relaxing state of mind.