The relationship between the sequencing and timing components of a skill.

The relationship between the sequencing and timing components of a skill was investigated in a serial reaction-time task. Two groups received extensive training on an identical sequence of events. For one group there was a constant timing interval between events, while in the other group the length of the timing interval varied from trial to trial. Following training, the sequence was occasionally broken by an event occurring out of its proper order or time. Although there was no difference between the two groups in the speed of responding to unexpected events, the group for which timing was an integral part of the skill showed higher error rates to certain types of unpredictable event. The results suggest that relative timing is an integral part of the motor program representation. The research reported in this paper is part of a Ph.D. thesis submitted to the University of Oregon under the direction of S. W. Keele, supported by an Office of Naval Research Contract No. N00014-67-A-0446-004 to S.W. Keele.