The illusion of absence in magic tricks

Recently, a curious illusion of absence has been described, where the space behind an occluder is compellingly experienced as empty. This illusion is similar to illusions based on amodal completion in the sense that it refers to occluded portions of a visual scene and informal observations suggest that it may also be largely impervious to conscious knowledge. The aim of the present experiment was to test the hypothesis that the illusion of absence is cognitively impenetrable in the same way as amodal completion. Participants viewed magic tricks based on either amodal completion, the illusion of absence, or attentional and reasoning misdirection and tried to infer the secret behind the tricks after one, two or three presentations. The results show that the tricks based on the illusion of absence are very difficult to debunk, even after repeated presentations. In this regard, they are similar to tricks based on amodal completion, but different from tricks based on attentional and reasoning misdirection. The participants also rated how magical they felt the tricks were. Surprisingly, the magic ratings tended to be quite high even in trials where the participants had already discovered the secret behind the trick. This unexpected finding may be taken to suggest that there may be two magical moments in the lifetime of a magic trick: In addition to the magical experience evoked by trick itself, discovering the secret behind the trick may also evoke an experience of impossibility.publishedVersio

A Perceptual Illusion of Empty Space Can Create a Perceptual Illusion of Levitation

A recent analysis of magic tricks suggests the existence of a perceptual illusion where the space hidden behind an occluding object is experienced as empty in a strangely compelling way. Here, we show that this illusion of absence is not just a trivial consequence of the lack of retinal stimulation but rather the result of an active process of perceptual construction. The results of a simple experiment show that this perceptual illusion of absence can in turn trigger perceptual processes which generate an immediate perceptual impression of levitation via a percept–percept coupling. This suggests that magical illusions of levitation are partially driven by an immediate perceptual impression of floating in thin air. The perceptual mechanisms underlying the illusion of absence are hitherto unknown, but our results provide support for a potential explanation based on the generic view principle.publishedVersio

Sammenhengen Mellom Svevende Objekter og Illusjonen Om Tomt Rom: Det Forunderlige Tilfellet av Amodalt Fravær

The aim of this study was to explore a phenomenon that has not been previously explored within the field of psychology, called amodal absence. Amodal absence refers to the process where the visual system fills in the area behind an object in the foreground of the visual field, resulting in an impression of nothingness behind the occluding object. The proposed mechanism for this is that the visual system excludes objects it deems unlikely would be completely hidden behind the occluding object. The phenomenon was explored using a pen resting on a pedestal, and different occluding screens used to hide the pedestal, but not the pen, from view. Amodal absence was measured by asking participants to rate the strength of their impression of the pen floating unsupported in midair. An impression of floating was taken as a sign of amodal completion by making it seem like there was nothing behind the screen supporting the pen. Our theory predicted a stronger impression of floating for a narrower occluding screen based on the generic view principle. The results showed a significantly stronger rating for floating impression when the pedestal was hidden from view as opposed to when it was not. There were mixed results for the effects of the narrower screen versus wider screen and so no conclusion was made regarding this hypothesis

The cognitive neuroscience of social learning in human evolution

Cumulative culture is believed to be a uniquely human form of social learning, and is therefore believed to be key in understanding how humans evolved such complex social organization and technologies. It is reasonable to believe that our capacity for cumulative culture is the result of a series of interconnected, complex evolutionary processes, but humans abilities for teaching, imitation and communication are believed to play a central role. We plan on combining brain imaging techniques and a transmissions chain design with transmission of evolutionary relevant tasks (knot tying and symbol-production) in order to look at the mechanisms of cumulative culture in a new way. By looking at the brain activation involved in acquiring and transferring these skills we aim to offer new insight on the cognitive and behavioral demands of these technologies and their effect on cultural evolution

The illusion of absence in magic tricks

Recently, a curious illusion of absence has been described, where the space behind an occluder is compellingly experienced as empty. This illusion is similar to illusions based on amodal completion in the sense that it refers to occluded portions of a visual scene and informal observations suggest that it may also be largely impervious to conscious knowledge. The aim of the present experiment was to test the hypothesis that the illusion of absence is cognitively impenetrable in the same way as amodal completion. Participants viewed magic tricks based on either amodal completion, the illusion of absence, or attentional and reasoning misdirection and tried to infer the secret behind the tricks after one, two or three presentations. The results show that the tricks based on the illusion of absence are very difficult to debunk, even after repeated presentations. In this regard, they are similar to tricks based on amodal completion, but different from tricks based on attentional and reasoning misdirection. The participants also rated how magical they felt the tricks were. Surprisingly, the magic ratings tended to be quite high even in trials where the participants had already discovered the secret behind the trick. This unexpected finding may be taken to suggest that there may be two magical moments in the lifetime of a magic trick: In addition to the magical experience evoked by trick itself, discovering the secret behind the trick may also evoke an experience of impossibility

A Perceptual Illusion of Empty Space Can Create a Perceptual Illusion of Levitation

A recent analysis of magic tricks suggests the existence of a perceptual illusion where the space hidden behind an occluding object is experienced as empty in a strangely compelling way. Here, we show that this illusion of absence is not just a trivial consequence of the lack of retinal stimulation but rather the result of an active process of perceptual construction. The results of a simple experiment show that this perceptual illusion of absence can in turn trigger perceptual processes which generate an immediate perceptual impression of levitation via a percept–percept coupling. This suggests that magical illusions of levitation are partially driven by an immediate perceptual impression of floating in thin air. The perceptual mechanisms underlying the illusion of absence are hitherto unknown, but our results provide support for a potential explanation based on the generic view principle