CAS technology is non-invasive and non-intrusive; the only direct contact with the patient is through their manipulation of a one handed steering wheel with a knob called a manipulandum. The patient sits in front of a computer screen and watches the automated presentation of computer generated displays that highlight various locations on the screen. The patient moves the manipulandum to indicate the highlighted location.
We continually change the strength of the highlighting perceptual signal by mixing that signal, designed to activate a particular cortical area, with a type of noise that impedes that activation. We continually monitor the patient’s accuracy in their ability to indicate the highlighted location on the computer screen.
The continual monitoring of the patients’ indication of the perceived stimulus allows us to assess the information processing capacity of the cortical area responsible for function in the selected stimulus domain. In effect, CAS technology is testing cortical circuits by inserting a signal and monitoring the response.
Importantly, the CAS approach to testing makes it independent of the patient’s language capabilities, and cultural, ethnic, educational, or socioeconomic background. Moreover, the testing environment does not effect results.