Temporal Uncertainty and Temporal Estimation Errors Affect Insular Activity and the Frontostriatal Indirect Pathway...

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• Action updating allows organisms to adapt to environmental changes by replacing old behaviors with new ones.
• Temporal uncertainty, or not knowing when to act, hinders successful action updating.
• Predictive coding frameworks suggest minimizing prediction errors is crucial for perception.

Purpose of the Study:

• To investigate how temporal uncertainty affects action updating in the brain.
• To test if temporal uncertainty decreases the right anterior insula's (rAI) sensitivity to prediction errors.
• To examine how temporal estimation errors modulate frontostriatal connections involved in motor control.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to collect brain activity data.
• Participants performed an action-update task combined with temporal estimation.
• Dynamic causal modeling (DCM) was applied to fMRI data to analyze effective connectivity between brain regions.

Main Results:

• Temporal uncertainty increased activity in the rAI and reduced its sensitivity to prediction errors, indicated by weaker rSMG→rAI connectivity.
• Temporal estimation errors weakened connections between the rPreSMA and rSTR (rPreSMA→rSTR), disrupting action updating.
• Modulation of rAI→rSTR connections by temporal estimation errors also contributed to action update failure.

Conclusions:

• The findings elucidate the neural basis of the horse-race model of action control.
• Unsuccessful action updating may be a homeostatic process reflecting a Bayes-optimal response to uncertainty.
• The study highlights the role of the rAI and frontostriatal pathways in managing temporal uncertainty during behavioral adaptation.