Hands-on adaptation: Bodily stimuli increase size adaptation aftereffect

Area of Science:

• Cognitive Psychology
• Visual Perception
• Neuroscience

Background:

• The size adaptation aftereffect demonstrates how prior exposure to stimuli alters current size perception.
• Biological significance may confer unique properties to body part size processing, but susceptibility to illusions remains unclear.

Purpose of the Study:

• To investigate if visual stimuli of body parts (hands) are more prone to size adaptation aftereffects than nonbody stimuli (abstract shapes).
• To explore the influence of stimulus identity and meaning on perceptual aftereffects.

Main Methods:

• The Uznadze illusion (size-contrast adaptation aftereffect) was induced in three experiments.
• Participants were exposed to pairs of hands or abstract shapes of differing sizes.
• Following adaptation, participants judged the size of new stimuli.

Main Results:

• A stronger size adaptation aftereffect was observed for hand stimuli compared to nonhand stimuli in Experiments 1 and 2.
• Experiment 3 confirmed a stronger adaptation for hands, particularly when nonhand stimuli were processed first, suggesting context-dependent effects.

Conclusions:

• Visual hand stimuli exhibit heightened susceptibility to size adaptation.
• The identity and attributed meaning of a stimulus play a significant role in modulating perceptual aftereffects, impacting visual processing.