How the brain makes choices: New map reveals the process

How the experiment worked 

Mice were trained to perform a choice task: a visual pattern appeared on either the left or right side of a screen, and the animal had to turn a wheel to bring it to the center. A correct move was rewarded with water, while an error triggered a burst of white noise.

The researchers also varied the probability of where the stimulus would appear. This allowed them to test how the brain combines incoming sensory data with prior expectations shaped by experience.

Using high-precision Neuropixels probes, the scientists recorded signals from hundreds of thousands of cells across multiple brain regions. The result was a panoramic view of how information about stimuli, choices, actions and rewards spreads through the nervous system.

Research results

The first of the two studies, “A brain-wide map of neural activity during complex behavior,” found that decision-making signals are spread far more widely than expected. Instead of being concentrated in just a few specialized regions, neural activity related to choices, movements and rewards was observed across nearly the entire brain.

This challenges the traditional view of a strict hierarchy in brain function and highlights the constant communication between different regions during complex behavior. The findings suggest that future neuroscience will need to take a more holistic, brain-wide perspective rather than focusing narrowly on isolated circuits.

The second paper, “Brain-wide representations of prior information,” focused on how the brain uses expectations built from recent experience. These prior beliefs were found not only in higher-order cognitive areas, but also in brain areas that process sensory information and control actions.

Remarkably, even early sensory hubs such as the thalamus, the first relay for visual signals from the eyes, carried traces of these expectations. This supports the idea of the brain as a “prediction machine,” with forecasts distributed across multiple structures to guide behavior. The authors note that this insight could shed light on disorders like schizophrenia and autism, which may involve differences in how expectations are formed and updated.

“Looking ahead, the team at International Brain Laboratory (IBL) plan to expand beyond their initial focus on decision-making to explore a broader range of neuroscience questions. With renewed funding in hand, IBL aims to expand its research scope and continue to support large-scale, standardised experiments. As per the IBL model, it will continue to share its tools, data pipelines and platforms with the global scientific community to democratise and accelerate science and enhance data reproducibility,” says the press release.

Earlier, Kazinform News Agency reported that multi-center clinical trial ADAPT (Alzheimer’s disease Diagnosis And Plasma P-Tau217) had been launched in the UK to introduce a blood test into the standard practice of diagnosing Alzheimer’s disease.