Enduring Interest in Perceptual Ambiguity: Alternating Views of Reversible Figures.

Abstract

Research favoring the so-called bottom-up and top-down classes of explanations for reversible figures that dominated the literature in last half of the 20th century is reviewed. Two conclusions are offered. First, any single-process model is extremely unlikely to be able to accommodate the wide array of empirical findings, suggesting that the "final" explanation will almost certainly involve a hybrid conceptualization of interacting sensory and cognitive processes. Second, the utility of distinguishing between 2 components of the observer's experience with reversible figures is emphasized. This distinction between the observer's ability to access multiple representations from the single stimulus pattern (ambiguity) and the observer's phenomenal experience of oscillation between those representations (reversibility) permits the literature to be segregated into useful categories of research that expose overlapping but distinctive cortical processes.

United we sense, divided we fail: context-driven perception of ambiguous visual stimuli

“…Such dissociation between stimulus and percept allows one to study how the brain 'chooses' between multiple correct interpretations in establishing a conscious percept. Two hallmark features of ambiguous visual stimuli are the mutual exclusivity of their possible perceptual interpretations and the perceptual alternations that occur between these interpretations when stimuli are continuously viewed [1,2]. Mutual exclusivity entails that, at any given moment, perception commits to one interpretation (the dominant percept) while disregarding or suppressing the other possibility.…”

Perceptual Reversal Guided by Integration Between Bottom-Up Input and Top-Down Feedback Over Time Course

“…The prevailing theory to explain perceptual reversal is neural satiation or fatigue hypothesis (Long & Toppino, 2004;Wagemans et al, 2012). In this view, reversal from one perceptual state to another state occurs if sets of neurons involved in a particular percept undergo satiation or fatigue with continuing inspection of a pattern.…”

How Does the Mind Handle Uncertainty in Ambiguous Figures?

“…Central cortical structures have long been invoked (e.g., Hering or Helmholtz) to explain perceptual reversal. Ambiguous figures demonstrate the role of expectations, world-knowledge and the direction of attention (see Long & Toppino, 2004) in relation to the perceptual interpretation of the stimulus.…”

“…When observers fixate on bistable ambiguous figures, perceptual alternations can take place, meaning that either one or the other interpretation is selected by visual awareness (Attneave, 1971;Kornmeier & Bach, 2012;Long & Toppino, 2004, for a review). In the four ambiguous figures shown in Figure 1, perceptual bistability implies giving a specific meaning to a particular feature.…”