Neural substrates of salience suppression

How do we ignore stimuli that are salient but irrelevant when our task is to select a lower salient stimulus? Since bottom-up processes would favour high saliency, the detection of a low salient target in the presence of highly salient distractors requires top-down attentional guidance. Previous studies have demonstrated that top-down attention can modulate perceptual processing but also that the control of attention is driven by fronto-parietal regions. However, to date there is scarcity of direct evidence on the cause and effect relation between control regions and perceptual processing.

The present project focuses on the neural mechanisms that implement salience supression in the brain. In particular we ask which neural areas provide a pro-active (preparatory) ’signal’ to guide the selection of a low or high saliency item, and which may be more critical for reactively suppressing salient information once it has been selected (a late correction mechanism). Furthermore, we look for the causal influence of these suppression signals in perceptual areas of the brain. The work will apply a system-neuroscience approach to understand not only the brain regions that are involved in this top-down attentional process but also the causal interaction between different brain regions and the functional mechanisms that bring about selection-by-salience.
The candidate will be expected to have some familiarity with brain imaging (fMRI, EEG) and brain stimulation (TMS, tDCS) techniques. Following training in the lab the candidate will need to perform such studies that combine those techniques (e.g., combined TMS/fMRI and TMS/EEG studies).