Duration estimation of visual light and dark stimuli

Estimation of visual light and dark stimuli duration is studied in eight subjects. The intervals are within the range of 100 to 1,100 ms. Three of the subjects were trained with intervals presented with light stimuli, the others - with dark stimuli. Time intervals presented in both ways were given for estimation to both groups of subjects. The extimates depend on the position of the time intervals in the range, on the type of the stimuli with which they are presented and on the way of training.