The ‘Psychological Refractory Phase’ and Ageing

Abstract

WHEN, in psychological experiments, the subject is required to respond as rapidly as possible to a signal closely following another, an increase in response latency is observed¹. It has become customary to refer to this aspect of high-speed sequential performance as the ‘psychological refractory period’ in analogy with changes in threshold of neurones, following the propagation of impulses, where the recovery is divisible into an ‘absolute’ and a ‘relative’ phase. Welford¹ has argued that the slowing of response to the second of two successive signals is due not to a temporary reduction of central sensitivity, but to the feature that “no two central organizing times can overlap”. His view is derived from that of Hick², who postulated that in continuous performance the brain is occupied not only in dealing with a particular signal but also with the monitoring of a response to it.