Prior probability modulates anticipatory activity in category-specific areas

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Computational Neuroscience

Background:

• Bayesian models are a leading framework for human information processing.
• Translating Bayesian principles to neural processes remains a challenge.
• Understanding the neural basis of prior probability and its impact on anticipatory activity is crucial.

Purpose of the Study:

• To investigate the neural underpinnings of prior probability.
• To examine the effect of prior probability on anticipatory activity in category-specific brain regions.
• To differentiate between graded and categorical neural responses to probabilistic information.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
• Participants underwent behavioral training to learn event probabilities and sequences.
• Cue-related anticipatory modulation was examined in the fusiform face area (FFA) and parahippocampal place area (PPA).

Main Results:

• Activity in the FFA was elevated when faces had a higher prior probability.
• This effect was observed specifically during the anticipation period, vanishing upon stimulus presentation.
• No anticipatory effects were found for houses in the PPA, indicating stimulus-specific sensitivity.

Conclusions:

• Prior probability modulates anticipatory activity in a graded manner within category-specific regions like the FFA.
• A functional distinction exists between anticipatory and stimulus-evoked activity concerning prior probability.
• The brain's predictive processing is sensitive to stimulus material, as shown by differential effects in FFA and PPA.