Figure 1. The convex front side (left) and the concave
back side (right) of a Charlie Chaplin mask. Even if we
know consciously about the concavity of the mask’s
backside (right figure), we perceive it as concave. Source: Max Planck
Institute for Biological Cybernetics, Tübingen, Germany
(see also Hill and Johnston 2007).
We study the processes underlying stable and unstable perception and
perceptual anomalies in order to better understand the
psychophysical relations. Particularly, we use ambiguous stimuli to
induce unstable perceptual states in highly controlled lab
environments. Unstable perceptual states serve as model states for
unstable mental states that are often observed in people with
exceptional experiences or people in altered states of
consciousness. With psychophysical methods, eye-movement recordings
and EEG, functional MRI and recently also with methods from
artificial intelligence, we try to better understand the processes
underlying unstable perceptual and mental states.
Figure 2. Adelsons Checker-Shadow Illusion (see also
Adelson EG 1993). Left: The square “B” appears much
brighter than the square “A”. Right: A yellow mask
isolates areas within the squares A and B from their
context. It becomes obvious, that both areas are in fact
equiluminant. Source: Michael Bach’s website of visual
illusions.
In cooperation with the Department
of Psychiatry and Psychotherapy at the Medical Center of the
University of Freiburg and the Psychiatric
Hospital Strasbourg, France we investigate in this context
patients with psychiatric disorders, who also show altered
perceptual and conscious states, in order to test our
models and hypotheses derived thereof. Concurrently, we also
try to better understand the focused disorders.