Unlike stimulus–response compatibility, which has been explored for aging effects, the motor behavior issue of response–response (R–R) compatibility has not been addressed in the gerontological literature. R–R compatibility refers to the ease with which two responses can be prepared together either simultaneously or as choice alternatives. In the present study, young, middle-aged, and elderly adult female subjects were tested in a two-choice reaction-time (RT) paradigm involving four types of finger movements paired in every possible choice combination, creating different levels of R–R compatibility. Significant age differences increased as R–R compatibility decreased. The practical significance of this study is to establish R–R compatibility as an important factor influencing task difficulty to which older adults are particularly sensitive and to encourage recognition of this factor when prescribing progressive motor-skill training in elderly clients.
Kathye E. Light is with the Department of Physical Therapy, University of Florida, P.O. Box 100154, Gainesville, FL 32610-0154. Waneen W. Spirduso is with the Department of Kinesiology and Health Education, University of Texas at Austin, Austin, TX 78712.