Effect of age, feedback, and practice on ability to respond within a fixed time interval

Accuracy and consistency of response within a fixed time interval as a function of age and practice with feedback were investigated. The task was pressing a telegraph key within a given interval following the last release of the key. The interval was empty and was pre-set at 2.75-3.24 sec. One piece of candy was dispensed for each inter-response-interval (IRI) which was correct. For both number of correct IRIs and SD of IRI significant effects were noted for Age, Feedback, and Practice. In addition, for SD of IRI, Age and Feedback interacted significantly. Magnitudinal feedback appeared to be more confusing than either specific or directional feedback and resulted in less improvement than either of the latter.