Temporal numerosity and the psychological unit of duration

"Functions relating the perceived number of flashes to the number of flashes presented were obtained for stimulus presentation rates varying from 10 to 30 flashes per sec. These relationships, called temporal numerosity functions, provide information regarding the rate of increase in the perceived number and indicate the existence of critical points in time following the onset of stimulation. It is assumed that these findings describe the temporal characteristics of a basic central process underlying perception. The results of these studies, and similar studies with other sense modalities, are considered in relation to the concept of the psychological unit of duration, or moment, and also in relation to certain neurophysiological processes whose temporal characteristics are markedly similar to those exhibited by the perceptual results."--Abstract.