Attentional Demands and Effects of Extended Practice in a One-Finger Key-PressingTask

摘要

This paper attempts to define mechanisms for producing rapid movement sequencesearly and late in practice. Twelve subjects completed eight hours of practice on a task in which a response consisted of a sequence of three key presses, the first two of which were fixed over all trials while the third was stimulus dependent. In some dual task blocks a low or a high pitched tone was presented during various phases of sequence production in order to determine attentional demands of sequence preparation and execution. The results show that attentional resources are required for preparing but not for executing the sequence. Extended practice was found to gradually improve anticipation of response production but no evidence was found for qualitative changes in the way the sequences were produced as suggested by notions of distributed programming and response integration. Secondary task interference reduced only little with practice. The present results provide further evidence for the notion that a general principle of producing movement sequences underlies one and multi-finger key press sequences. In contrast to assumptions of multiple resource theories about parallel processing the results suggest that when more than one task require attention at the same time, limited attentional resources are and remain a major bottle-neck for dual task performance. This is evidence for a single channel model of task performance.