The modulation of selective attention and divided attention on cross-modal congruence

Previous studies have demonstrated that performance under selective attention and divided attention can be enhanced or impaired, depending on whether the stimuli from different modalities are the same or different. However, it remains unclear whether the modulation of selective attention and divided attention on cross-modal congruence involves shared or distinct neural mechanisms. To clarify this, the present study adopted an audiovisual Stroop task (measuring selective attention) and an audiovisual Matching task (measuring divided attention), using the same physical stimuli, along with event-related potential (ERP) and time-frequency measures. The behavioral results revealed better performance when the auditory and visual stimuli were the same in both tasks. Electroencephalography (EEG) results revealed that different auditory and visual stimuli elicited increased N2 and late positive component (LPC) amplitudes, as well as increased theta power, in both tasks. Moreover, in the audiovisual Matching task, the P3 amplitude was lower in the different condition, and the delta power was greater in the same condition. However, in the audiovisual Stroop task, the amplitude of the N450 component was greater, and beta power was lower, in the different condition. These results indicate that both shared and distinct neural mechanisms underlie the modulation of different types of attention on cross-modal congruence.