Category-Biased Neural Representations Form Spontaneously during Learning That Emphasizes Memory for Specific...

Area of Science:

• Cognitive Neuroscience
• Perception Psychology

Background:

• Category learning can lead to perceptual biases, making items within a category seem more similar.
• It remains unclear how category bias develops when learning emphasizes individual stimuli or if it emerges spontaneously during learning.

Purpose of the Study:

• To investigate category biases in neural representations during stimulus encoding.
• To determine if category bias develops spontaneously even when learning individual stimuli.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used during stimulus encoding.
• Neural pattern classification and similarity analyses tracked category information in the brain.
• Participants learned full names for face-blend stimuli indicating category membership.

Main Results:

• Stimulus category was decodable across multiple brain regions during encoding.
• Similar category items showed more similar neural representations in the prefrontal cortex than dissimilar category items.
• This occurred even when participants focused on individual stimuli and category-irrelevant features.

Conclusions:

• Category labels can spontaneously bias neural representations during encoding.
• This bias emphasizes category-relevant information, even without explicit categorization tasks.
• Bias emerges when category information is present, irrespective of focus on individuals.