Poster B12, Sunday, March 26, 8:00 – 10:00 am, Pacific Concourse
Spatial attentional asymmetries in a cross-modal visual search task and the role of the frontal eye field
Dario Cazzoli1, Rebecca E. Paladini1, Lorenzo Diana1, Giuseppe Zito2, Urs P. Mosimann1,3, Thomas Nyffeler1,4, René M. Müri1,5, Tobias Nef1; 1University of Bern, Bern, Switzerland, 2Imperial College, London, United Kingdom, 3Private Hospital Wyss, Münchenbuchsee, Switzerland, 4Luzerner Kantonsspital, Luzern, Switzerland, 5Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland
During visual search, visuospatial attentional deployment can also be influenced by stimuli in other sensory modalities, such as additional auditory stimuli. Recent accounts propose that multisensory processing can have asymmetrical effects on spatial attentional deployment. Moreover, the frontal eye field (in particular the right FEF, rFEF) is thought to maintain spatial saliency maps of relevant stimuli for both visual and auditory modalities, and might thus play a central role in these multisensory processes. The aim of the present study was to investigate potential asymmetries in the spatial deployment of visual attention, as triggered by additional auditory information during visual search. Moreover, we aimed at assessing the role of the rFEF, by applying continuous Theta Burst Stimulation (cTBS), an inhibitory transcranial magnetic stimulation protocol. Healthy participants were asked to find a target within a visual array, accompanied by spatially valid, invalid, neutral, or no auditory stimuli, before and after cTBS application over the rFEF. The results revealed that, in comparison to the purely visual condition, spatial congruency between the multisensory visuo-auditory information elicited a behavioural facilitation in search performance. Conversely, spatial incongruence had detrimental effects, and triggered spatial asymmetries in behavioural performance, particularly when visual targets were placed in the periphery of the search field. Importantly, inhibitory cTBS over the rFEF seemed to significantly reduce these asymmetries. The findings are discussed within the framework of current accounts postulating a modulation of hemispheric asymmetries and spatial attentional deployment by multisensory processing, and suggest a central role of the rFEF in these processes.
Topic Area: ATTENTION: Multisensory