How the brain deals with uncertainty

Amazing stuff!

"... The thalamus is a sort of crossroads within the brain, made up of cells that connect distant brain regions to one another. Its mediodorsal region sends signals to the prefrontal cortex, where sensory information is integrated with our goals, desires, and knowledge to guide behavior. Previous work in the Halassa lab showed that the mediodorsal thalamus helps the prefrontal cortex tune in to the right signals during decision-making, adjusting signaling as needed when circumstances change. Intriguingly, this brain region has been found to be less active in people with schizophrenia than it is in others. ...
By manipulating and recording activity in the animals’ brains, the researchers found that the prefrontal cortex got involved every time mice completed this task, but the mediodorsal thalamus was only needed when the animals were given signals that left them uncertain how to behave. ...

Within the mediodorsal thalamus ... found a subset of cells that were especially active when the animals were presented with conflicting sound cues. These neurons, which connect directly to the prefrontal cortex, are inhibitory neurons, capable of dampening downstream signaling. ..."

From the abstract:

"... Here, we identified two distinct mediodorsal projections to prefrontal cortex that play complementary mechanistic roles in decision making under uncertainty. Specifically, we found that a dopamine receptor (D2) expressing projection amplifies prefrontal signals when task inputs are sparse and a kainate receptor (GRIK4) expressing projection that suppresses prefrontal noise when task inputs are dense but conflicting. Collectively, our data point to distinct brain mechanisms for handling uncertainty due to low signals versus high noise, while also providing a mechanistic entry point for correcting decision-making abnormalities in disorders with a prominent prefrontal component."

How the brain deals with uncertainty | MIT News | Massachusetts Institute of Technology Dedicated circuits evaluate uncertainty in the brain, preventing it from using unreliable information to make decisions.

Thalamic circuits for independent control of prefrontal signal and noise (no public access)