Positive and negative hysteresis effects for the perception of geometric and emotional ambiguities

• DOI: 10.1371/journal.pone.0202398
• Publication Date: 2018-09-26T17:44:39Z
• Authors: Emanuela Liaci; Andreas Fischer; Harald Atmanspacher; Markus Heinrichs; Ludger Tebartz va...; Jürgen Kornmeier
• Keywords: Stimulus (psychology); Inflection point

Aim The present study utilizes perceptual hysteresis effects to compare the ambiguity of Mona Lisa's emotional face expression (high-level ambiguity) and geometric cube stimuli (low-level ambiguity). Methods In two experiments we presented series nine Lisa variants variants. Stimulus was manipulated by changing mouth curvature (Exp. 1) cubes' back-layer luminance 2). Each experiment consisted three conditions, with opposite stimulus presentation sequences increasing decreasing degrees ambiguity, respectively, a third condition random sequence. Participants indicated happy or sad percepts alternative 3D 2) key presses. We studied influences priori biases (long-term memory) order (short-term on perception. Results Perception followed sigmoidal functions morphing parameters. parameter for functions' inflection points depended strongly similar effect sizes but different signs types (positive / priming cubes; negative adaptation Lisa). were located in middle between those from directional conditions stimuli. For stimuli, they superimposed one function ordered condition. Discussion reflect influence short-term memory during disambiguation ambiguous sensory information. are size, explaining up 34% variance introduced paradigm. explain qualitative difference positive cubes. addition, paradigm allows quantitative determination impact resolution ambiguities. asymmetric shifts case is likely due an bias, reflecting long-term memory. Whether corresponding also exist so far unclear.