Bayesian interpretation of the prefrontal P2 ERP component based on stimulus/response mapping uncertainty

Area of Science:

• Cognitive Neuroscience
• Computational Neuroscience

Background:

• The brain operates as a predictive system, utilizing prior information to estimate posterior probabilities and minimize uncertainty.
• Event-related potentials (ERPs), specifically the P3 component, are traditionally linked to decision-making and target probability uncertainty within a Bayesian framework.
• The prefrontal P2 (pP2) component, also associated with decision-making, has not been previously explored within the Bayesian framework.

Purpose of the Study:

• To investigate the association of the prefrontal P2 (pP2) component with different sources of uncertainty within a Bayesian brain model.
• To differentiate the uncertainty-related functions of the pP2 component from the well-established P3 component.

Main Methods:

• Three visuomotor tasks were designed to independently modulate uncertainty related to target probability and stimulus-response (S/R) mapping.
• Event-related potentials (ERPs) were recorded and analyzed, focusing on the amplitude of the pP2 and P3 components.

Main Results:

• The pP2 component exhibited its largest amplitude in tasks with high stimulus-response (S/R) mapping uncertainty, decreasing as S/R predictability increased.
• The P3 component's amplitude was maximal in tasks with greater target probability uncertainty.
• These findings confirm the P3's role in processing target probability uncertainty and establish the pP2's association with S/R mapping uncertainty.

Conclusions:

• The prefrontal P2 (pP2) component is associated with stimulus-response (S/R) mapping uncertainty, complementing the P3's role in target probability uncertainty.
• The pP2, potentially originating from the anterior insular cortex, may facilitate response selection by minimizing S/R uncertainty and supporting evidence accumulation.
• This research extends the Bayesian view of the brain by identifying a novel ERP correlate for S/R mapping uncertainty in decision-making processes.