Information Gain in Tasks involving Different Stimulus-Response Relationships

IN an attempt to clarify issues raised by changes associated with age in the ability of human subjects to perform perceptual-motor tasks, the rates of information transmission of younger and older subjects in performing discrete, choice reaction time tasks involving two different stimulus-response relationships were calculated. The tasks involved moving a stylus as quickly as possible from a central point to one of a number of targets arranged in a semi-circle in response to the appearance of one of a number of signal lights arranged in a similar semicircle. The first (direct) stimulus-response relationship required subjects to aim at targets corresponding directly in position to signals which appeared. In the second, indirect version of the task, the correct target was the ‘mirror image’ of that directly indicated by the signal.