It may be fun to perceive illusions, but the understanding of how they work is even
more stimulating and sustainable: They can tell us where the limits and capacity of
our perceptual apparatus are found—they can specify how the constraints of perception
are set. Furthermore, they let us analyze the cognitive sub-processes underlying our
perception. Illusions in a scientific context are not mainly created to reveal the failures of
our perception or the dysfunctions of our apparatus, but instead point to the specific power
of human perception. The main task of human perception is to amplify and strengthen
sensory inputs to be able to perceive, orientate and act very quickly, specifically and
efficiently. The present paper strengthens this line of argument, strongly put forth by
perceptual pioneer Richard L. Gregory (e.g., Gregory, 2009), by discussing specific visual
illusions and how they can help us to understand the magic of perception.
The present study challenges the notion that judgments of artistic quality are based on stable aesthetic standards. We propose that such standards are a delusion and that judgments of artistic quality are the combined result of exposure, elaboration and discourse. We ran two experiments using elaboration tasks based on the Repeated Evaluation Technique (RET) in which different versions of the Mona Lisa had to be elaborated deeply. During the initial task, either the version known from the Louvre or an alternative version owned by the Prado was elaborated; during the second task, both versions were elaborated in a comparative fashion. After both tasks, multiple blends of the two versions had to be evaluated concerning several aesthetic key variables. Judgments of artistic quality of the blends were significantly different depending on the initially elaborated version of the Mona Lisa indicating experience-based aesthetic processing, which contradicts the notion of stable aesthetic standards.
One of the many questions surrounding Leonardo’s Mona Lisa concerns the landscape visible in the portrait’s background: Does it depict an imagination of Leonardo’s mind, a real world landscape or the motif of a plane canvas that hung in Leonardo’s studio, behind the sitter? By analyzing divergences between the Mona Lisa and her Prado double that was painted in parallel but from another perspective we found mathematical evidence for the motif-canvas hypothesis: The landscape in the Prado version is 10% increased but otherwise nearly identical with the Louvre one, which indicates both painters used the same plane motif-canvas as reference.
Processing fluency plays a large role in forming judgments, as research repeatedly shows. According to the Hedonic Fluency Model, more fluently processed stimuli are rated more affectively positive than less fluently processed stimuli. Most research documenting such findings uses neutral or positive stimuli with low complexity, thus any potential impact of initial stimulus valence cannot be tested. In the present study, 60 IAPS stimuli ranging from very negative to very positive valence were rated on liking by participants. Processing fluency was manipulated through perceptual priming (7 ms). Results of Experiment 1 (N = 35) support the prediction of the Hedonic Fluency Model, but only for stimuli with an initially positive valence. However, when negative stimuli were processed more fluently, they were rated as more negative than when processed less fluently. Experiment 2 (N = 39) showed that enhancing the accessibility of the stimulus content (via prolonging the prime duration to 100 ms) cannot account for the results of Experiment 1, since Experiment 2 failed to replicate the findings obtained in Experiment 1. Potential factors influencing affective evaluation of negative stimuli are discussed. A model is offered for the reinterpretation of processing fluency as an amplifying factor for evaluative judgment.
People’s sketches of human faces seem to be systematically distorted: The eyes’ position is always higher than in reality. This bias was experimentally analyzed by a series of experiments varying drawing conditions. Participants either drew prototypical faces from memory (studies 1 and 2: free reconstruction; study 3: cued reconstruction) or directly copied average faces (study 4). Participants consistently showed this positioning bias, which is even in accord with facial depictions published in influential research articles by famous face researchers (study 5). We discuss plausible explanations for this reliable and stable bias which is coincidentally similar to the morphology of Neanderthals.