Grouping and refractoriness in multiple selective responses.

Some experiments are described on selective reactions to a varying number (1-4) of successively presented signals. In one set of conditions, subjects were instructed to handle signals in strict succession, while in another set, subjects were asked to give one multiple response after all signals had arrived (grouping). The results showed that both instructions could be well obeyed, but striking differences in performance were found between grouping and successive handling.