Research Interests

How is it that our mind produces the vividness and beauty of the visual world? Why are we aware at all if we can imagine beings that function very well without the need for conscious perception? There will probably not be a satisfying answer to this question soon. I hope that at least I can contribute to understanding what cognitive and neural mechanisms are important for awareness or even necessary for it to emerge.

Continuous flash suppression (CFS) is a powerful method used to render stimuli invisible. Using the breaking CFS paradigm, Timo Stein and I showed that one should be cautious with the interpretation of unconscious processing differences found with this paradigm. In addition, we recently found that a subcortical path seems to play no role in fear detection. how difficult it is to demonstrate unconscious processing differences found quite large effects for unconscious processing differences, for example in the processing of faces in general or of facial emotion depending on spatial frequency. With the same technique, Guido Hesselmann and I showed that subjective and objective measures of awareness lead to different neural correlates.

I'm interested in testing some of the basic assumptions about neural processes underlying awareness. For example, if you are aware of a chair, then processes reflecting awareness of the chair also have to carry information specific to this chair. As simple as this may sound, our current methods are still quite limited in demonstrating such specificity beyond category-specific brain regions. However, some theories assume that information about the percept (i.e. the chair) gets distributed to frontal and parietal brain regions where they become globally available. I use functional magnetic resonance imaging and machine-learning techniques to test whether (and under which circumstances) this is the case.