Comparison of Mindflex Toy to EEG Research System
Uploader: flwalker10
Original upload date: Fri, 10 Dec 2010 00:00:00 GMT
Archive date: Sun, 05 Dec 2021 23:48:12 GMT
Professor Zhong Lin Lu ,Professor Psychology and Biomedical Engineering and William M. Keck Chair in Cognitive Neuroscience at the University of Southern California, conducted this experiment to demon
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strate how a wet towel creates an antenna to conduct ambient indoor electrical signals, thus simulating brainwave activity when using both a standard Electroencephalograph (EEG) machine and a Mattel Mindflex EEG toy.
In this video, Professor Lu explains how the MindFlex toy can be influenced with a wet towel as input.EEG devices measure and amplify the very small voltages (differences in electrical potential) created by the functioning brain. Due to its designed sensitivities, an EEG device will also measure any small voltage present at its input, including electricity from the 60 Hz power grid, cellular signals, muscle induced electrical artifacts, etc.
Dr. Lu's idea is that a wet towel in a normal interior office setting will pick up electrical noise in the environment, detecting small voltages that any EEG device will measure. An EEG signal is acquired in the MindFlex as input to algorithmic equations meant to estimate the user's mental state. Certain patterns in a normal EEG signal are correlated with certain mental states. The ball in the Mindflex game will rise when the mental state is achieved and the associated pattern is measured. In the case of the wet towel, random noisy input will have no such correlation, so will make the ball rise and fall randomly.
To test this idea, Professor Lu connects a typical research grade EEG system, a 128-channel model by NeuroScan, to a mannequin head topped with a wet towel to create conductivity. For the actual experiment, Dr. Lu used only a single channel, a ground and a reference point, rather then the full 128 channels, to more accurately represent the sensor configuration of the single-channel Mindflex. The NeuroScan EEG system is the white box placed behind the keyboard, and the mannequin with red towel is on the far left.
The output of the NeuroScan EEG system is displayed continuously on the bottom of the LCD screen. The randomly fluctuating traces can be mixed with the 60 Hz noise. In this setup, these random ambient fluctuations appear on the display, but, with no screen, the MindFlex toy manifests these fluctuations by randomly driving the ball up and down.
In summary, Professor Lu demonstrates that all EEG equipment will pick up random ambient noise when connected with a wet towel, and explains that this could randomly drive the ball up and down in the MindFlex toy.