Task complexity, accuracy, and reaction time.

An attempt was made to examine one specific aspect of response complexity - accuracy demand. Three groups, each of 12 subjects, were presented with two parallel lines of dots on a moving paper strip. Dots were in pairs at random intervals, and subjects were required to cross over the dots with a pen when a tone sounded. Subjects were required to cross over either zero, one, or two dots sequentially. From zero dots to one dot, there was an increase in reaction time (RT), presumably due to the more stringest error limits required in the latter. RT did not increase from one dot to two dots, but increased movement time (MT) was found. Results suggest that RT involves programming of movement initiation, and that MT includes some programming of the ongoing response. Accuracy demand differentially influenced RT and MT.