“…(Angell, 1907, p. 64) While many early 20th Century psychologists discussed consciousness and its investigation in their writings, very few did so specifically in relation to rivalry. McDougall, 1911McDougall, , 1930. In studies using Schröder's staircase and binocular color rivalry, he found similarities in their (successive) interval durations, and in the effect of voluntary control and monocular atropine administration on percept dominance (1901a, 1901b, 1903a, 1906).…”