Monocular and binocular sensitivity, as assessed by increment detection and RT tasks, was measured in 2 experiments (4 experienced psychophysical and 3 naive observers) to determine whether a phenomenally suppressed eye can interact with the dominant eye to yield binocular facilitation in excess of probability summation. Results indicate that binocular summation occurs during suppression. Sensitivity appears to be impaired in the suppressed eye, but that eye's residual sensitivity is integrated with the normal sensitivity of the dominant eye. (25 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1982 American Psychological Association.