Abstract: A small, portable and inexpensive apparatus, and a testing method using the same, are employed to obtain objective data about children to differentiate between hyperactive and non-hyperactive children. In a Delay Task, the child depresses a button, and after at least a predetermined delay interval depresses the button again. Points are scored if the child waits for a sufficient time, but no point is scored if the child presses the button too soon. In a Vigilance Task, a stream of symbols, which can be numerical digits, is presented in a random or pseudorandom order. If the child sees a "1" followed by a "9", the child is instructed to depress the push-button, but not to otherwise. The number of correct responses, errors of commission, (depressing the button at the wrong time) and errors of omission, (failure to depress the button) are recorded. At the end of the task, the data for the tested child are compared with normative data, and an analysis can be made of the child's tendency toward hyperactivity.