Motor programming of rapid finger sequences: inferences from movement-related brain potentials

The present study investigated the predictions of two prominent models (Klapp, 1995, 2003; Rosenbaum, Inhoff, & Gordon, 1984) of programming of response sequences with the help of behavioral data, the foreperiod Contingent Negative Variation (CNV) and the Lateralized Readiness Potential (LRP). Participants performed one-key and three-key responses with their left or right hand in a precuing task. Sequence length was manipulated across blocks and precues provided either no information, partial information about hand or start finger, or full information about the response. A sequence length effect was indicated by reaction time when the precue provided partial or full information. The LRP data suggested that the duration of motor processes increases with sequence length. Foreperiod LRP and CNV revealed that participants preprogram only the first element of the sequence and prepare multiple responses if the precue provides only partial information. We discuss the implications of current findings for the two models.