Cascade

Visualization of 75,000 neurons (colored dots) active across the brain of an adult mouse across different stages of a decision-making task. Dot size reflects a cell’s average firing rate, such that larger dots indicate more active neurons. The color of each dot represents a different grouping of related brain regions. Data collected as part of the International Brain Laboratory’s effort to create a whole-brain map of behavior. Click image to enlarge.
Credit: Dan Birman (University of Washington/Allen Institute)

It starts with a trickle, something akin to the first phase of the OODA loop of Observe, Orient, Decide, Act process when the brain decides how to act in a given situation when dealing with the real world in real time as shown by amazing work done by researchers at the University at Washington/Allen Institute.

Earlier work in mice had already hinted that choice, action, and engagement are distributed, not isolated in one cortical spot. The new map strengthens that view with coverage of hundreds of regions and clear timing.

Feedback mattered, too. When trials were correct and reward was delivered, wide swaths of the brain lit up together, reflecting both the liquid reward and the licking movements that came with it.

A companion paper tested how prior expectations, built from recent trials, are encoded. Mice estimated the block’s left-right probabilities and performed better when the stimulus was weak, including zero-contrast trials.

The authors decoded signals for this subjective prior in 20 percent to 30 percent of recorded regions spanning early sensory areas like the thalamus, motor areas, and higher cortex. 

Crucially, prior signals were present even before a new stimulus appeared and were detectable very early after it arrived.

That result explains how expectations can nudge perception without crossing into conscious awareness.

OODA Loop