Whether attentional loads influence audiovisual integration depends on semantic associations

Neuronal studies have shown that selectively attending to a common object in one sensory modality results in facilitated processing of that object’s representations in the ignored sensory modality. Thus, the audiovisual (AV) integration of common objects can be observed under modality-specific selective attention. However, little is known about whether this AV integration can also occur under increased attentional load conditions. Additionally, whether semantic associations between multisensory features of common objects modulate the influence of increased attentional loads on this cross-modal integration remains unknown. In the present study, participants completed an AV integration task (ignored auditory stimuli) under various attentional load conditions: no load, low load, and high load. The semantic associations between AV stimuli were composed of animal pictures presented concurrently with semantically congruent, semantically incongruent, or semantically unrelated auditory stimuli. Our results demonstrated that attentional loads did not disrupt the integration of semantically congruent AV stimuli but suppressed the potential alertness effects induced by incongruent or unrelated auditory stimuli under the condition of modality-specific selective attention. These findings highlight the critical role of semantic association between AV stimuli in modulating the effect of attentional loads on the AV integration of modality-specific selective attention.