Figure 1. Experimental procedure of the EEG experiment.

Overview of the different conditions in the EEG experiment. All stimuli pairs consisted of simultaneously presented auditory and visual stimuli, but the task differed between the conditions. A/V: simultaneously presented auditory and visual stimulus to be compared, V-A: visual stimulus of the 1^st pair and auditory stimulus of the 2^nd pair to be compared, A-A: auditory stimulus of the 1^st pair and auditory stimulus of the 2^nd pair to be compared, V-V: visual stimulus of the 1^st pair and visual stimulus of the 2^nd pair to be compared. The V-A condition was also used in the behavioural task, with and without distracters presented in the time period of 0.2–1.6 s.