A program for measuring timing and accuracy in a complex motor reaction task

A program was developed to explore a subject's accuracy and response timing in a reaction-time paradigm, which involves a multiple choice along with a complex response. The program can be run on an IBM-PC or compatible computers. The subject's task is: (1) to react to a stimulus (task) pattern by releasing a go-key (release time); the pattern is displayed on a keyboard as a combination of up to five light-emitting diodes associated with five answer keys; (2) then to press correctly the key combination indicated (response completion time). The keys are located at positions corresponding to finger tips. The response is complete at the moment all keys of the required combination are held down simultaneously, the order in response completion is not important. Responses are classified according to possible errors: whenever a key is pressed that does not belong to the required combination or the full key combination is not held until a (preset) waiting time period, the response is classified as incorrect. Various task patterns representing the required response combination of any subset of the five keys can be designed. Both the left and the right hand can be tested separately. In this way, possible distortions in performance caused, for instance, by apraxia can be analyzed. Basic statistical characteristics of the release times and completion times for correct responses are computed from the data and stored. The program is written in MODULA-2, the output files are in the ASCII format, which enables further processing of the data by standard statistical packages.