by masteruan @ instructables.com:
This tutorial will explain how to build a machine for biofeedback. But first a bit of theory.
What is biofeedback?
Biofeedback is the process of gaining greater awareness of many physiological functions primarily using instruments that provide information on the activity of those same systems, with a goal of being able to manipulate them at will. Some of the processes that can be controlled include brainwaves, muscle tone, skin conductance, heart rate and painperception.
Biofeedback may be used to improve health, performance, and the physiological changes that often occur in conjunction with changes to thoughts, emotions, and behavior.
Lie Detector and Biofeedback Arduino Based – [Link]