State and process limitations in information processing: An additive factors analysis

In a 2-choice discrimination task, the effects on reaction time of stimulus quality (a state-limiting variable), stimulus similarity (a process-limiting variable), and stimulus compatibility (another process-limiting variable) were found to be additive in 2 separate experiments, each with 20 undergraduates. Following the logic of the additive factors method, it appears that stimulus quality, stimulus similarity, and stimulus-response compatibility affect 3 distinct stages of processing, which were identified as encoding, memory comparison, and response selection, respectively. This outcome supports the notion that state and process limitations have separate and independent effects on information processing and implies that process limitations can be further subdivided into more specific sources of performance limitation. (PsycINFO Database Record (c) 2006 APA, all rights reserved).