Poster F4, Tuesday, March 27, 8:00-10:00 am, Exhibit Hall C
Integrating modality-specific expectancies for the deployment of spatial attention
Paola Mengotti1, Frank Boers1, Pascasie L. Dombert1, Gereon R. Fink1,2, Simone Vossel1,3; 1Research Centre Juelich, Germany, 2University Hospital Cologne, Germany, 3University of Cologne, Germany
The deployment of spatial attention is highly sensitive to predictability. Despite evidence for strong crossmodal links in spatial attentional systems, it remains to be elucidated how concurrent but divergent predictions for targets in different sensory modalities are integrated. We investigated the processing of modality-specific expectancies using a multimodal cueing paradigm in which auditory cues predicted the location of visual or tactile targets with modality-specific cue predictability. The cue predictability for visual and tactile targets was manipulated independently. A Bayesian ideal observer model with a weighting factor was applied to individual response speed to model the trial-wise inference about modality-specific cue predictability levels and their degree of integration. The weighting factor was analyzed in relation to cue predictability levels and divergence. We performed three behavioral studies, each including (n=21) healthy young participants. In Experiment 1 only the predictive spatial cue was presented, whereas in Experiment 2 an additional cue indicated the modality of the upcoming target. Results of the first two experiments showed that the degree of integration depended on the level of cue predictability and on the divergence of the modality-specific probabilistic contexts. When the two probabilistic contexts were matched in their level of predictability and were highly divergent (Experiment 3), higher separate processing was favored, especially when visual targets were processed. These findings suggest that modality-specific predictions are flexibly integrated according to their inferred reliability, supporting the hypothesis of separate modality-specific attentional systems that are however linked to guarantee an efficient deployment of spatial attention across the senses.
Topic Area: ATTENTION: Multisensory