EFFECT OF TIME INTERVALS BETWEEN 2 SHORTLY SPACED ACOUSTIC SIGNALS ON RESPONSE TIMES TO SECOND

An experiment on the psychological refractory period was carried out, in which two successively presented acoustic signals were given to four Ss. S1 was a single-valued click not requiring an overt reaction, and S2 was a double-valued tone asking for a binary choice response. Interspacing of S1 and S2 was regular and irregular. The interstimulus intervals (ISI) ranged from 50 to 500 msec. The presence of S1 yielded an inverse relationship between RT and ISI from 50 to 250 msec for all Ss, but at longer ISI RT tended to increase. Time uncertainty exerted a lengthening effect on RT. Further, the curvilinearity between RT and ISI was more marked. Omission of S1 effectuated nearly no discrepancy between regular and irregular ISI presentation, but RT in the without S1 conditions were generally longer than RT in the with S1 conditions. © 1969.