Concept formation and categorization of complex, asymmetric, and impossible figures

Area of Science:

• Visual perception
• Cognitive psychology
• Computational vision

Background:

• Impossible figures present perceptual inconsistencies between local and global structures.
• Understanding the salience of global perceptual properties is key to visual cognition.

Purpose of the Study:

• To investigate if "impossibility" is a salient perceptual property guiding categorization.
• To compare the salience of impossibility with other global properties like complexity and symmetry.

Main Methods:

• Category formation tasks were employed, where participants sorted shapes based on perceived natural groupings.
• Experiments involved varying sets of possible and impossible figures, and assessing sorting performance.
• Drawing figures before sorting and explicit categorization instructions were also tested.

Main Results:

• Participants rarely sorted figures by impossibility spontaneously; only half succeeded after multiple attempts.
• Object complexity was a highly salient property for categorization, while symmetry was not.
• Explicit instructions improved performance for symmetry but not for impossibility.

Conclusions:

• Global properties are important in perception, but not all are equally salient or easily utilized.
• Impossibility is a less salient perceptual dimension compared to object complexity for natural categorization.