How Does Your Brain Know a Cat Is a Cat?

Key Points:

• Neuroscientists Lisa Feldman Barrett and Earl Miller propose that the brain constructs categories, such as recognizing a cat, through top-down predictions rather than bottom-up sensory processing; the brain forms hypotheses based on past experience before sensory input is fully processed.
• Their theory, published in Nature Reviews: Neuroscience, aligns with Barrett's theory of constructed emotion, emphasizing that both perception and emotion are actively constructed by the brain using past experiences, internal bodily signals, and cultural context.
• The brain constantly predicts sensory input and cancels expected signals to conserve resources, updating its predictions only when unexpected or missing information arises, explaining how categorization works even in novel situations.
• This predictive model challenges traditional notions of objectivity and bias, suggesting that perception is inherently subjective and shaped by individual brain predictions, with consensus among diverse perspectives being the closest approach to objective knowledge.
• The researchers also link categorization processes to mental health, suggesting that disorders like depression and autism may involve problems with overgeneralization or undergeneralization of categories, and highlight the importance of broadening experiences to reduce harmful biases.