Decision processes in selective attention: Response priming in the Stroop color-word task

In a random discrete-trials version of the Stroop color-word task, two subsets of trials were compared: (1) trials in which the current distractor word named the color response just made in the preceding trial, and (2) trials in which the current stimulus was unrelated to the previous stimulus. Shorter response latencies and fewer errors in the first condition suggest either that (a) increasing the availability of a response can facilitate its rejection (incompatible with passive strength-of-activation theories), or that (b) the redundancy of the current distractor response and still-potent preceding response reduces the total number of highly activated competing responses present on the current trial. The latter hypothesis is favored by a second experiment in which Stroop stimuli were preceded by a warning signal which “primed” the distractor response, the appropriate color response, an unrelated response, or no response. That the efficiency of selective attention is affected by the number of simultaneous competing responses even when number of input channels remains constant supports theories of attention which place capacity limitations subsequent to stimulus identification.