The Dependence of Frequencies of Seeing on Procedural Variables: III. The Time-Interval Between Successive Stimuli

Abstract
Two experiments involving 6 S''s each were performed with a Hecht-Schlaer Model III Adaptometer. No evidence was found that the 50 per cent threshold is dependent upon the length of the inter-trial interval within the range 3 to 12 secs. covered in these experiments. "Statistically significant differences between values of the "SD," or slope constant of the PR function did occur as a function of the inter-trial intervals used in the second experiment; these differences, however, were not observed in the first experiment.".