The Dimension Action (DA) model asserts that the visual system is modular, and that each task involves multiple-response mechanisms rather than a unitary-response selection mechanism. The model has been supported by evidence from single-task interference paradigms. We use the psychological refractory period paradigm and show that dual-task…

Two theories of comparative judgment were compared across four experiments on their ability to explain the Baldwin figure, a focal line whose apparent length is affected by square boxes at or near its endpoints. (Editor)

A uniprocessor, unidimensional model, based on Krueger's noisy-operator theory, was fitted satisfactorily to data from four published studies of tone comparison. The model predicts faster response time on different judgments because of heterogeneity of difference. (Author/CP)