Abstract: A method and apparatus are presented for testing a human operator, and in particular a small child, for brain dysfunction, which method and apparatus require the human operator to perform a primary task which includes centering a spot of light on a reference point by rapidly moving a control stick back and forth. The primary task is provided by a Zero Input Tracking Analyzer (ZITA) unit that has no initial input and automatically nulls the operator's error, from his previous attempt to center the spot, with each subsequent attempt. In order to make more prominent any evidence of brain dysfunction, a secondary task is provided by an Auxiliary Distraction Task (ADT) unit which produces a "distraction stress" while the operator is carrying out the primary task. This task requires the human operator to respond to the stimuli of high or low tones, presented to him by headphones, by moving another control stick forward or backward for the high and low pitches, respectively.

Abstract: An improved method and apparatus for measuring the effects of stress on a person's performance of a primary task, while a secondary task is also provided to be performed simultaneously by the test subject and the results of such measurements providing parameters for diagnosing various physiological and mental disorders. A multiple mode and variable format secondary task command stimulus generator is provided which detects the lack of and/or correctness of the response of the test subject to the secondary task command stimuli.