Extensionality of information accompanying effect of numerosity on estimation of time duration.

60 subjects estimated the duration of the stimulus consisting of 1, 3, or 5 dark dots, following the auditory warning signal. The duration of the warning signal constituted duration of foreperiod which was either 1 or 5 sec. For the correlated groups, pitch of the warning signal weas perfectly correlated with numerosity of dots. For the uncorrelated group, there was no such correlation. For the constant group, pitch of the warning signal was constant. The increasing effect of numerosity of stimulus elements was reduced for the 5-sec foreperiod but not for the 1-sec. foreperiod in the correlated group. Such effect was present for both durations for foreperiod in the uncorrelated group and was absent for both durations of foreperiod in the constant group.