The size of the ventriloquist effect is modulated by emotional valence

It is currently unknown to what extent the integration of inputs from different modalities are subject to the influence of attention, emotion, and/or motivation. The ventriloquist effect is widely assumed to be an automatic, crossmodal phenomenon, normally shifting the perceived location of an auditory stimulus toward a concurrently-presented visual stimulus. The present study examined whether audiovisual binding, as indicated by the magnitude of the ventriloquist effect, is influenced by threatening auditory stimuli presented prior to the ventriloquist experiment. Syllables spoken in a fearful voice were presented from one of eight loudspeakers while syllables spoken in a neutral voice were presented from the other seven locations. Subsequently, participants had to localize pure tones while trying to ignore concurrent light flashes (both of which were emotionally neutral). A reliable ventriloquist effect was observed. The emotional stimulus manipulation resulted in a reduced ventriloquist effect in both hemifields, as compared to a control group exposed to a similar attention-capturing but non-emotional manipulation. These results suggest that the emotional system is capable of influencing crossmodal binding processes which have heretofore been considered as being automatic.