Project B1

PIs: Thomas Töllner, Zhuanghua Shi, and Hermann J. Müller

One notion central to a number of traditional and contemporary selective attention models holds that the total amount of attentional resources is limited, entailing that the brain has evolved to cope with the continuing information (over-) load by adaptively selecting and prioritizing behaviourally relevant sources of information. The dimension-weighting account (DWA), for instance, proposes that this capacity limitation affects, in the first instance, information processing at a pre-attentive level of processing: the coding of stimulus saliency. Moreover, our recent findings revealed that pre-attentive saliency computations can be modulated–selectively and/or interactively–by a variety of factors, including top-down expectancies, previous trial history, or aging. The present project is designed to examine whether this adaptive DWA framework is limited to visual processing or, alternatively, may be extendable to sensory modalities. By coupling behavioural (mental chronometry, accuracy) and electrophysiological measures (event-related lateralizations, oscillations)–recorded during a new multimodal search paradigm–to computational modelling (priors), the present project focuses particularly on the role of (i) top-down expectancy, (ii) bottom-up saliency, and (iii) intertrial history biases in the guidance of cross-modal search. The outcome of this project will provide a deeper understanding of dynamic, short-term adjustments of brain states before, during, and after adaptive attentional orienting to multisensory events.