Chapter 4
NeuroSky Technology Overview
Brainwaves
e last century of neuroscience research has greatly increased our knowledge about the brain and
particularly, the electrical signals emitted by neurons ring in the brain. e patterns and frequencies
of these electrical signals can be measured by placing a sensor on the scalp. e MindBand contains
NeuroSky inkGear™ technology, which measures the analog electrical signals, commonly referred to
as brainwaves, and processes them into digital signals to make the measurements available to games and
applications. e table below gives a general synopsis of some of the commonly-recognized frequencies
that tend to be generated by different types of activity in the brain:
Brainwave Type
Frequency range
Mental states and conditions
Delta
0.1Hz to 3Hz
Deep, dreamless sleep, non-REM sleep, unconscious
eta
4Hz to 7Hz
Intuitive, creative, recall, fantasy, imaginary, dream
Alpha
8Hz to 12Hz
Relaxed, but not drowsy, tranquil, conscious
Low Beta
12Hz to 15Hz
Formerly SMR, relaxed yet focused, integrated
Midrange Beta
16Hz to 20Hz
inking, aware of self & surroundings
High Beta
21Hz to 30Hz
Alertness, agitation
ThinkGear
inkGear is the technology inside every NeuroSky product or partner product that enables a device
to interface with the wearers’ brainwaves. It includes the sensor that touches the forehead, the contact
and reference points located on the ear pad, and the on-board chip that processes all of the data. Both
the raw brainwaves and the eSense Meters (Attention and Meditation) are calculated on the inkGear
chip.
eSense
eSense™ is a NeuroSky's proprietary algorithm for characterizing mental states. To calculate eSense,
the NeuroSky inkGear technology ampli es the raw brainwave signal and removes the ambient
noise and muscle movement. e eSense algorithm is then applied to the remaining signal, resulting
in the interpreted eSense meter values. Please note that eSense meter values do not describe an exact
number, but instead describe ranges of activity.
November 29, 2011
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