Stimulus generalization was hypothesized to represent the outcome of a perceptual (for primary stimulus generalization) or conceptual (for secondary stimulus generalization) categorization process. Perception and conception were distinguished by differential speed and locus of action and by varying susceptibility to irrelevant and redundant information. Within a semantic generalization paradigm, S's right forearm muscle potentials to semantic and homographic generalization words were recorded. Time interval and stimulus display characteristics of the presentations of the generalization word were varied. Results indicated little support for the view of stimulus generalization as a categorization process. There was, however, support for the differential susceptibility of perception and conception to variations in stimulus display characteristics.
