This study investigates visual detection performance when subjects must monitor two locations. The goal is to expand upon analytic methods capable of identifying the nature of the processing architecture involved in two different tasks, and to compare obtained performance with predictions derived from these analytic methods. In the OR task, subjects are instructed to respond 'yes' upon detection of either input. In the AND task, correct 'yes' responses depend upon detection of both inputs. Both tasks were explored in the context of a supra-threshold experiment (where reaction [RT] is dependent variable) and a near-threshold detection experiment (where response accuracy is the dependent variable). Analyses confirm parallel processing of the two input signals, and indicate that operations performed on the channel outputs vary according to the logical requirements of each task. In addition, both RT and near-threshold detection accuracy are related through the identification of analogous stochastic operators.