Is the perception of velocity determined by the prior discrimination of spatial and temporal distances? Two experiments sought to answer this question by comparing the discriminabilities of moving stimuli varied in spatial extent, temporal duration, or in redundant combinations of both variables. (Editor)

A series of experiments tested a recent suggestion that vertical symmetry of a stimulus display can serve as a visual diagnostic for responding "same" in a letter-matching task. The data of chief interest were same reaction times to vertically symmetric (e.g., AA) and asymmetric (e.g., LL) displays, each composed of two side-by-side uppercase…

The experiments reported here are aimed at exploring in more detail the possibility that context can improve perception itself. In particular, they are concerned with clarifying the conditions under which context might aid perception and with localizing the stage of processing at which context would have its effects. (Author)