[EEG] Mind Flex EEG hacking article

Dan Brown danbrown at gmail.com
Tue Apr 13 13:38:19 PDT 2010

>From http://ericmika.com/itp/brain-hack :

The Mind Flex (but not the Froce Trainer) provide eight values
representing the amount of electrical activity at different
frequencies. This data is heavily filtered / amplified, so where a
conventional medical-grade EEG would give you absolute voltage values
for each band, NeuroSky instead gives you relative measurements which
aren’t easily mapped to real-world units. A run down of the
frequencies involved follows, along with a grossly oversimplified
summary of the associated mental states.

Delta (1-3Hz): sleep
Theta (4-7Hz): relaxed, meditative
Low Alpha (8-9Hz): eyes closed, relaxed
High Alpha (10-12Hz)
Low Beta (13-17Hz): alert, focused
High Beta (18-30Hz)
Low Gamma (31-40Hz): multi-sensory processing
High Gamma (41-50Hz)

In addition to these power-band values, the NeuroSky chip provides a
pair of proprietary, black-box data values dubbed “attention” and
“mediation”. These are intended to provide an easily-grokked reduction
of the brainwave data, and it’s what the Force Trainer and Mind Flex
actually use to control the game state. We’re a bit skeptical of these
values, since NeuroSky won’t disclose how they work, but a white paper
they’ve released suggests that the values are at least statistically
distinguishable from nonsense.

Here’s the company line on each value:

Indicates the intensity of a user’s level of mental “focus” or
“attention”, such as that which occurs during intense concentration
and directed (but stable) mental activity. Distractions, wandering
thoughts, lack of focus, or anxiety may lower the Attention meter

Indicates the level of a user’s mental “calmness” or “relaxation”.
Meditation is related to reduced activity by the active mental
processes in the brain, and it has long been an observed effect that
closing one’s eyes turns off the mental activities which process
images from the eyes, so closing the eyes is often an effective method
for increasing the Meditation meter level. Distractions, wandering
thoughts, anxiety, agitation, and sensory stimuli may lower the
Meditation meter levels.

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