Biography
During my PhD I have investigated several visual phenomena and focused on how the visibility and the appearance of these phenomena depend on the relationship between different elements in the visual scene. After obtaining my PhD at the Donders Institute in Nijmegen (The Netherlands) under supervision of Rob van Lier, I moved to Lausanne (Switzerland) where my first postdoc at EPFL with Michael Herzog focused predominantly on the visual reference frame in which different types of visual processing take place. In 2012 I received a Pegasus Marie Curie postdoc grant to work for 3 years in Leuven (Belgium) on the mechanisms responsible for perceptual suppression, for which I collaborated with Raymond van Ee and Johan Wagemans. Throughout the past years I have continued to collaborate with Rob van Lier and Stuart Anstis on several award winning color illusions. Currently I am working as a postdoc in Steve Engel's vision and imaging lab in Minneapolis, where we use both psychophysics and electrophysiology to investigate how the brain effectively adapts and remains adapted to changing visual environments. |
RESEARCH TOPICS
Representing invisible visual inputIn a few recent studies performed at KU Leuven, I have looked at how stimuli that are not consciously perceived are still represented by the visual system. We have shown that training to suppress a stimulus increases the depth of suppression of this stimulus. In another study, we show that even when parts of an object are invisible, the visual system can still integrate them with visible stimulus parts into a single coherent representation.
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Neural measures of visual plasticity
Here at University of Minnesota we measure steady state visually evoked potentials (SSVEPs) in response to contrast adaptation and showed thus far that contrast adaptation reduces the amplitude and delays the phase of SSVEPs. In addition, in a recent study at KU Leuven, we found increased higher order SSVEP responses as the result of shape categorisation training. These different approaches show that SSVEPs can be used as a reliable neural measure of visual plasticity.
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Perceptual grouping and visual awarenessIn two of my PhD projects at Donders Institute we showed for two perceptual suppression phenomena, flash-induced fading and binocular rivalry, that visual stimuli appear and disappear simultaneously more often when they are similar in terms of color and shape than when they are dissimilar on these features. These effects highlight the tight relation between perceptual organisation and visual awareness.
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Color illusions
In several visual illusions we show in a powerful and playful way how color appearances are to a large extent determined in relation to the context in which colors are presented. Most of these illusions were created in collaboration with Stuart Anstis (UCSD) and Rob van Lier (Donders Institute) and won several international awards throughout the past decade.
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