ABSTRACT
In internal clock models, one source of attentional control is in a pacemaker-accumulator system, where some perceptual representation of duration is built. The relation between produced intervals and prebreak duration is linear in both high-and low-frequency conditions, suggesting that the duration and frequency of shifts are relatively stable throughout the prebreak duration. In contrast, effects of breaks in stimuli to be timed were systematically investigated using the peak-interval procedure in animal timing research, which provided reference data and a useful theoretical framework to interpret interruption-related effects. Interruption in the accumulation process was inferred from effects of nontemporal processing on concurrent time estimation. The proposed interpretation of the break location effect referred to an internal clock framework where accumulation of temporal information is assumed to require attention. The increase in expectancy level should intensify attentional shifting between accumulation and monitoring for the break signal, which should in turn reduce the rate of pulse accumulation.
