title: Temporal Processing in Bistable Perception of the Necker Cube.
abstract: Perception of ambiguous figures is unstable and alternates repeatedly between possible interpretations. Some approaches to explaining this phenomenon have, so far, assumed low-level bottom-up mechanisms like adaptation and mutual inhibition of underlying neural assemblies. In contrast, less precise top-down approaches assume high-level attentional control mechanisms generalised across sensory modalities. In the current work we focused on specific aspects of the top-down approach. In a first study we used dwell times (periods of transiently stable percepts) and the parameters of dwell time distribution functions to compare the dynamics of perceptual alternations between visual (Necker cube) and auditory ambiguity (verbal transformation effect). In a second study we compared the endogenous alternation dynamics of the Necker cube with parameters from two attention tasks with different regimes of temporal dynamics. The first attention task (d2) is characterised by endogenous self-paced dynamics, similar to the dynamics underlying perceptual alternations of ambiguous figures, and we found clear correlations between dwell time parameters (Necker cube) and processing speed (d2 task). The temporal dynamics of the second (go/no-go) attention task, in contrast, are exogenously governed by the stimulus protocol, and we found no statistically significant correlation with the Necker cube data. Our results indicate that both perceptual instability and higher-level attentional tasks are linked to endogenous brain dynamics on a global coordinating level beyond sensory modalities.
authors.affiliation: Collegium Helveticum, ETH Zürich, Schmelzbergstrasse 25, 8092 Zürich, Switzerland j_wernery@gmx.ch.
authors.forename: Jannis
authors.initials: J
authors.lastname: Wernery
authors.affiliation: Collegium Helveticum, ETH Zürich, Schmelzbergstrasse 25, 8092 Zürich, Switzerland.
authors.forename: Harald
authors.initials: H
authors.lastname: Atmanspacher
authors.affiliation: Institute for Frontier Areas of Psychology and Mental Health, Wilhelmstraße 3a, 79098 Freiburg, Germany University Eye-Hospital, Kilianstrasse 5, 79106 Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kornmeier
authors.affiliation: Collegium Helveticum, ETH Zürich, Schmelzbergstrasse 25, 8092 Zürich, Switzerland.
authors.forename: Victor
authors.initials: V
authors.lastname: Candia
authors.affiliation: Collegium Helveticum, ETH Zürich, Schmelzbergstrasse 25, 8092 Zürich, Switzerland.
authors.forename: Gerd
authors.initials: G
authors.lastname: Folkers
authors.affiliation: Institute for Frontier Areas of Psychology and Mental Health, Wilhelmstraße 3a, 79098 Freiburg, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Wittmann
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D006801:Humans; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: Necker cube; bistability; verbal transformation effect; vision