Researchers have analyzed the brain’s role in identity expectations. They determined that neurons in the midbrain flag an error when there is a discrepancy between what we expect and what actually happens, and then the orbitofrontal cortex updates our expectations.
Thorsten Kahnt is an assistant professor of Neurology at Northwestern University Feinberg School of Medicine.
“This happens all the time in our lives,” said Professor Kahnt. “Whenever there’s a mismatch between what we expect to experience and what we actually experience, our brain has to register the error and update our expectation. These changing expectations are fundamental for making decisions. Now we know how this happens in the brain.”
While previous studies have described the role of the midbrain regarding personal preferences, this is the first paper to show its role in encoding identity errors.
“It could be as basic as taking your kid to the park and expecting green grass, but instead the ground is a big, muddy puddle,” said Professor Kahnt. “Your midbrain responds to the error, and the orbitofrontal cortex updates the information, so you know what to expect tomorrow.”
Dopamine neurons were found to encode errors that relate to our preferences. Because of this, Professor Kahnt theorized that identity errors are also encoded by dopamine, which is likely released at the neuron’s axon terminal in the orbitofrontal cortex where it updates information.
A separate study recently demonstrated that dopamine neurons encode identity expectations errors in mice. The experts used functional magnetic resonance imaging (fMRI) data to show increased midbrain activity when the mice were presented with an odor that was not expected based on the corresponding food item.
Patterns of brain activity in the orbitofrontal cortex of the mice were found to have encoded the identity of the food item that was expected. Once the new food and odor association had been introduced, the identity expectations changed in the orbitofrontal cortex accordingly.
The study was published in the journal Nature Communications.