Non-intentional but not automatic: reduction of word- and arrow-based compatibility effects by sound distractors in the same categorical domain.

In the current study, we show that the non-intentional processing of visually presented words and symbols can be attenuated by sounds. Importantly, this attenuation is dependent on the similarity in categorical domain between the sounds and words or symbols. Participants performed a task in which left or right responses were made contingent on the color of a centrally presented target that was either a location word (LEFT or RIGHT) or a left or right arrow. Responses were faster when they were on the side congruent with the word or arrow. This bias was reduced for location words by a neutral spoken word and for arrows by a tone series, but not vice versa. We suggest that words and symbols are processed with minimal attentional requirements until they are categorized into specific knowledge domains, but then become sensitive to other information within the same domain regardless of the similarity between modalities.