Modality switching (and the absence thereof) modulates the redundant signal effect

Description

Responses to bimodal signals are faster than those to their unimodal constituents. This so-called redundant signal effect (RSE) is affected by modality switching, where changing modality in a random trial sequence causes a slowing of responses. Critically, while unimodal trials can follow full modality switches (e.g., an auditory following a visual signal), bimodal trials can follow only partial switches (e.g., an audiovisual following a visual signal). Thus, the effect of full modality switches on bimodal responses is unknown. Here, in addition to the standard instruction to detect any auditory or visual signals, we presented tactile target signals in the random trial sequence. Consequently, bi- and unimodal trials can follow full modality switches (e.g., an audiovisual following tactile signal). Our data show that modality switching modulates the RSE, including violations of Miller’s bound, which is often interpreted as a benchmark result indicating multimodal processing interactions. We find larger violations occurring in full modality switch trials and smaller (but still present) ones in modality repetition trials. Interestingly, unlike their unimodal counterparts, bimodal responses are not (or only marginally) affected by full modality switches. Thus, the observed modulation of the RSE is largely driven by unimodal responses that are slowed due to modality switching. Therefore, understanding modality switching and its differential effect on uni- and bimodal responses will be key to fully understanding the processes underlying the RSE.

Period	Jun 2024
Event title	22nd International Multisensory Research Forum
Event type	Conference
Location	Reno, United StatesShow on map
Degree of Recognition	International