Visual estimation of filled or unfilled short time intervals

A definition is given of filled and unfilled short time intervals presented visually by light and dark stimuli. A reply is given to the question whether the existence of events in a given time interval influences the estimation of the duration of this interval. The mean values of the estimations of filled intervals are lower compared with the mean values of the estimations of single unfilled intervals of the same duration. The influence of the complexity of the task on the mean values of the estimations is discussed. The results obtained are explained in terms of the motor theory of perception.