The semantic Simon effect

Three experiments are reported in which a semantic variant of the Simon paradigm was used. In Experiment 1, participants saw Dutch and English words that corresponded to names of animals (e.g. DOG) or occupations (e.g. TEACHER). Participants were instructed to respond by saying ANIMAL or OCCUPATION, depending on whether the presented word was a Dutch or English word (i.e. relevant stimulus feature) but irrespective of whether the word was the name of an animal or an occupation (i.e. irrelevant stimulus feature). Results showed that responses were facilitated when the correct response corresponded to the name of the semantic category of the presented word (e.g. saying "ANIMAL" to DOG) compared to when it was the name of a different semantic category (e.g. saying "occupation" to Dec), even though the semantic category of the presented word was irrelevant and had to be ignored. Category membership also influenced response times when letter case (upper- or lower-case: Experiment 2) and grammatical category (noun or adjective: Experiment 3) had to be determined in order to select a category label as a response. The semantic Simon effect offers a new tool that can be used to study automatic semantic processing.