"Pupil size changes were monitored during the solution of various types of problems. A number of solution and response strategies were required of the subject.

"Pupil size changes were monitored during the solution of various types of problems. A number of solution and response strategies were required of the subject. There was strong confirmation of the theory that this autonomic index can provide a sensitive measure of the fluctuating levels of attention and arousal, which are associated with the various aspects of information processing and response." PDF link (bad quality): http://www.filedropper.com/article http://www.filedropper.com/article