Rafaela – Argyri Tsouvalou


  • Ph.D. Candidate in Cognitive Psychology. Department of Psychology, School of Social Sciences, University of Crete (2019 – ).
  • M.Sc. Cognitive Neuroscience and Neuropsychology. Department of Psychological Sciences, Birkbeck, University of London, UK (2018/19).
  • B.Sc. Psychology. Department of Psychology, School of Social Sciences, University of Crete (2013 – 2018).

Postdoctoral Research

The effect of grouping principles in achromatic perception.

Brief Description

Perceptual grouping occupies a leading role in achromatic perception. Two fundamental questions remain unsolved in regard to perceptual grouping both in general and ,more specifically, in achromatic perception. The first question refers to how exactly this grouping is achieved. Which rules are implemented by our visual system in order for the perceptual elements to be grouped into corresponding groups? The second question refers to the way by which these perceptual groups interact with each other in order to compute the perceived lightness of a surface. To answer in the first question this thesis evaluates the effectiveness of two hypotheses proposed by Kardos (1934) and Gilchrist et al. (1999). In regard to the second question, the systematic variation of well – known grouping principles is investigated, by implementing these grouping principles in simple and complex lightness illusions. Additionally, this thesis investigates the effect of focused attention in the perceptual grouping, a factor that is understudied in achromatic perception.

Research Funding

  • Economou Elias, Assistant Professor of Cognitive Psychology, Department of Psychology, University of Crete (supervisor)
  • Sunčica Zdravković, Full Professor of Perception, Department of Psychology, University of Novi Sad, Serbia (co – supervisor)
  • Georgia Grigoriou, Assistant Professor of Physiology, Department of Medicine University of Crete (co – supervisor)

Publications in peer-reviewed journals

  • Tsouvalou, R. A., & Economou, E. (2016). Changes in highest luminance of the backgrounds do affect the lightness of targets in Simultaneous Lightness Contrast. ΕΛΕΥΘΕΡΝΑ, 8, 223-236.

Poster Presentations