Perception and meta-perception

During prolonged observation of the ambiguous Necker cube (Fig. 1a Necker 1832), one of the most prominent so-called ambiguous figures, our perception becomes unstable and switches spontaneously between two possible interpretations (Fig. 1b ) back and forth. When depth information is added to the image of the Necker cube, the altered cube becomes unambiguous and our perception becomes stable. In a series of EEG studies with different ambiguous stimuli and disambiguated variants, we looked for differences between the unstable neural representation of ambiguous and the stable representation of unambiguous visual information (Kornmeier & Bach 2009, Kornmeier et al. 2016, Joos et al. 2020a and 2020b). To our surprise, we found a very clear EEG pattern across fundamentally different stimulus categories with low amplitudes of two event-related potentials (“ERPs”, P200 and P400) for ambiguous stimuli and high amplitudes for unambiguous stimulus variants (Fig. 2columns 1 to 3).

However, ambiguity does not seem to be the decisive factor here, as we found very similar results when we manipulated the visibility of visual stimuli, e.g. the mouth curvature of happy and sad smileys (Fig. 2, right column), or the lines of letters (here without illustration).
In cooperation with the Department of Psychiatry and Psychotherapy at the Medical Center at the University of Freiburg and the Department of Psychiatry at the University of Strasbourg, we are investigating patients with psychiatric disorders, some of whom suffer pathologically from unstable perceptual and/or mental states, in order to test models and the resulting hypotheses and at the same time gain a better understanding of these disorders.