A confluence of contexts: Asymmetric versus global failures of selective attention to stroop dimensions

In 6 experiments probing selective attention through Stroop classification, 4 factors of context were manipulated: (a) psychophysical context, the dis tinctiveness of values along the color and word dimensions; (b) set size co ntext, the number of stimulus values tested; (c) production context, the mo de used to respond; and (d) covariate context, the correlation between the dimensions. The psychophysical and production contexts mainly caused an asy mmetry in selective attention failure between colors and words, whereas the set size and covariate contexts contributed primarily to the average or gl obal magnitudes of attentional disruption across dimensions. The results su ggest that (a) Stroop dimensions are perceptually separable, (b) J. R. Stro op's (1935) classic findings arose from his particular combination of conte xts, and (c) stimulus uncertainty and dimensional imbalance are the primary sources of task and congruity effects in the Stroop paradigm.