Experience produces the atypicality bias in object perception.

Area of Science:

• Cognitive psychology
• Perceptual science
• Object recognition

Background:

• The atypicality bias describes a phenomenon where perceptual similarity judgments are skewed towards atypical exemplars.
• This bias has been observed in faces, birds, and cars, indicating a broad influence on object perception.

Purpose of the Study:

• To investigate whether the atypicality bias can be induced in novel, artificial objects.
• To determine the conditions under which this bias emerges for unfamiliar stimuli.

Main Methods:

• Generation of two categories of artificial
• blob
• stimuli, each with typical and atypical members.
• Creation of morphs by averaging typical and atypical parent exemplars.
• Testing for the atypicality bias before and after participants engaged in category discrimination training or a pleasantness rating task.

Main Results:

• An atypicality bias was not present before category training but emerged after participants learned to discriminate between blob categories.
• Similarly, the bias was absent before the pleasantness rating task but became evident afterward.
• These results indicate that exposure, even passive, influences similarity perception.

Conclusions:

• The atypicality bias is not limited to pre-existing categories and can be induced for novel objects.
• Familiarization through categorization or passive exposure is sufficient to establish this bias.
• The atypicality bias reflects how exposure influences perceptual similarity judgments.