How category learning affects object representations: not all morphspaces stretch alike.

Area of Science:

• Cognitive Psychology
• Neuroscience
• Visual Perception

Background:

• Category learning's impact on visual perception is debated, with conflicting findings.
• Existing research shows mixed results regarding enhanced object discriminability after category learning.
• The structure of morphspaces used in studies may explain these discrepancies.

Purpose of the Study:

• To investigate how different morphspace structures influence the effect of category learning on visual object perception.
• To determine if factorial morphspaces, compared to blended morphspaces, better support enhanced discriminability after category learning.
• To clarify the role of morphspace design in interpreting neuroimaging findings on category learning and object representations.

Main Methods:

• Created matched factorial and blended morphspaces using the same four morphparents.
• Assessed the effect of category learning on object discriminability within both morphspace types.
• Examined the creation of functional dimensions in response to category learning in each morphspace.

Main Results:

• Category learning selectively increased discriminability along relevant dimensions in the factorial morphspace.
• No significant increase in discriminability was observed in the blended morphspace.
• Functional dimensions were created in the factorial space but not in the blended space.

Conclusions:

• Morphspace structure critically determines whether category learning enhances visual discriminability.
• Factorial morphspaces, unlike blended ones, support enhanced object discriminability and functional dimension creation.
• Previous neuroimaging studies showing limited effects of category learning may be constrained by their use of blended morphspaces.