The pharmacology of human information processing

Abstract

A serial information processing model provides a rough but useful framework for studying effects of age and drugs on human cognition. Using this approach, one varies both the nature of experimental tasks and the biology of the subjects, and one measures both reaction time and event-related potential latencies. For example, we may change a task by varying the complexity of the stimulus or the complexity of the response. We may change the biology of the subject by giving drugs or by using subjects of different ages. The interactions of the independent variables on reaction time and ERP latencies yield convergent data on the properties of information processing stages and on the actions of biological variables upon them. Using this approach we find that methylphenidate acts late on response-related processes while aging acts on earlier and on stimulus-related process. A review of other studies shows the value of this approach, but is balanced by illustration of some its problems and shortcomings.