Reaction time measurement of temporal integration and organization of form

Temporal integration of patterned stimuli was investigated by introducing an interstimulus interval (ISI) between brief exposures of two matrices of illuminated squares. These matrices were identical except for their spatial displacement, arranged such that they could be superimposed to yield either horizontal or vertical stripes. Choice reaction times to the composite stripe orientation were a progressively increasing function of ISI, suggesting some integration over an ISI range in excess of 224 msec. Similar functions were obtained with both regular and irregular order of ISI presentation. The results from an additional experiment employing an extraneous warning signal discounted the possibility that preparatory factors developing over the ISI were responsible for the obtained reaction time functions.