On a variant of Stroop's paradigm: Which cognitions press your buttons?

The Stroop effect typically refers to the fact that the time to identify th e color of a visually presented word is affected by the relationship betwee n the word and the color. When the (irrelevant) word is semantically relate d to the color (e.g., the word green, presented in red) response time is sl ower than if the word is neutral or unrelated. One question that has been p osed concerns whether semantics plays a role only when the task requires an explicit verbal response, or whether it also plays a role when the respons e is manual. Sharma and McKenna (1998) have reported that semantics plays a role only when the response is vocal. A reanalysis of their data shows tha t semantics also plays a role when manual responses are made.