Visual-auditory interactions on explicit and implicit information processing

Interactions among sensory information are important for generating a coherent percept of the external world. Facilitation and inhibition effects in cross-modal perception have been widely studied for decades. The present study tried to confirm the interaction effects between sensory information in a bimodal context and explore these influences when part of the sensory information was presented without participants' subjective awareness. A total of 40 undergraduate participants were recruited in this mixed design study. Participants were required to count the flashing of the black circle (visual task) or the presentation frequency of the beep sound (auditory task) with the presence of either congruent or incongruent sensory signals in the background. Participants in the explicit group generally performed more accurately and also faster with the congruent stimuli than with the incongruent stimuli. Performance accuracy in the visual task in the implicit group was affected by the non-target sound signals which were presented beneath participants' subjective awareness. The better performance yielded in the auditory task than in the visual task was explained by the appropriateness of the auditory stimulation to the task nature. In addition, the supportive findings regarding processing without awareness should be interpreted with caution.