To what extent is our perception and understanding of the world governed by genetically fixed and pre-programed mechanisms, as opposed to being shaped by learning and experience within the physical and social environment? The answers to these questions are an integral part of our concept of human life. They will define our potential to adapt and hence which roles we can potentially play in the physical and social systems we live in. Those fundamental questions have been the centrepiece of my scientific research. Ongoing projects are:
Sensory Augmentation and genAI: This research is inspired by our advanced module “AI Applications in Psychology” (PSYC3083/6178). It aims primarily at understanding the effects of sustained genAI use on cognition and builds on the methodological approach to sensory augmentation developed by Witzel et al (2023).
Colour Perception & Language: Investigating colour naming as a prime example for understanding the relationship between perception and language has been my ongoing core interest; for reviews and perspectives, see Siuda-Krzywicka et al (2019), Witzel & Gegenfurtner (2018), and Witzel (2018).
What is colour for? This research is about understanding the purpose and contribution of being able to see colour. The foundations of this research have been developed in Siuda-Krzywicka et al (2019), Witzel & Gegenfurtner (2018), and Witzel (2018). As part of her PhD, Michaela Trescakova collected exciting new data on this.
Perceived Atmosphere: Giulio Palma is working on the effect of lighting on perceived atmosphere and the role of colour in nostalgia as part of his PhD. Exciting future directions involve the integration of other perceptual features and real-world applications, for example, in marketing and retail design.
Complementary Colours: Complementary colours allow us to understand the most fundamental mechanisms of colour processing. Recent work (Witzel 2025) shows how complementary afterimages can probe the first stage of colour processing in the cone photoreceptors of the eye. PhD student Rio Coleman investigates other types of complementary colours to probe mechanisms along the hierarchy of visual processing.
The Multisensory Nature of Perceptual Reality: From her first research for her PhD, Yihui Lu got smashing data on the ecological origin of correspondences between colour and sound; some preliminary work may be found in this conference video (Witzel et al VSS 2022).
Lighting and spectral imaging: This theme extends research begun with former PhD student Hamed Karimipour (Karimipour et al 2023; Witzel & Karimipour 2024), aiming at colour constancy, lighting design, and computational approaches spectral imaging.
