Effect of attentional load on audio-visual integration: an ERP study

Audio-visual integration (AVI) is higher in attended conditions than unattended conditions. However, how the AVI was altered with the change of attentional load is rarely studies. In the current study, A dual-task paradigm including an auditory/visual discrimination task, evaluating the AVI effect and a rapid serial visual presentation task, manipulating the attentional load was conducted. The behavioral results showed faster response to all target under no- and low-attentional-load conditions than under high-attentional-load condition. The EEG analysis showed the theta and alpha oscillatory activity was higher for bimodal audio-visual stimulus than individual auditory or visual stimuli, and significantly highest AVI theta and alpha power under low-attentional-load condition than that under low-and high-attentional-load conditions (low > no = high). These results suggested AVI was greatly affect by attentional load.