Researchers unveil cognitive blueprint detailing choice-making processes in the brain
In a groundbreaking discovery, a team of international neuroscientists, led by Michael Halassa from the International Brain Laboratory, have constructed a detailed neural map of activity across the entire brain during decision-making. The research, published in two studies and presented in the journal Nature on September 3, has been hailed as a transformative development in neuroscience, comparable to the Sloane Digital Sky Survey in its impact.
The brain map was created using a standardized procedure and digital neural probes called Neuropixels. Over 22 labs collaborated to gather data from 139 mice, encompassing activity from more than 600,000 neurons in 279 areas of the brain.
The experiments involved mice wearing electrode helmets while controlling the movement of a black-and-white striped circle on a screen. Mice that successfully steered the circle to the center received a reward of sugar water. The neural activity during this process was meticulously recorded.
One study outlined the widespread distribution of electrical activity related to decision-making. The activity during decision-making first spiked in areas of the brain that process visual input. As the decision-making process progressed, activity then spread across the brain, with motor-controlling areas lighting up as a mouse's decision culminated in movement. Widespread brain activity followed when the mouse received its sugary reward.
The new map reveals that neural activity is far more widespread than previously thought, with electrical signals pinging across nearly all of the mouse's brain during different stages of decision-making. The brain was found to access prior knowledge early in decision-making, as previously hypothesized.
Another study used the data to evaluate how expectations shape choices. Researchers included an extra challenge for the mice, requiring them to recall past visual stimuli to make decisions.
Mindy Weisberger, a science writer, is the author of "Rise of the Zombie Bugs". She did not contribute to the research but her work sheds light on the importance of such collaborative efforts in advancing our understanding of the brain.
The International Brain Laboratory, which produced the brain map, aims to inspire more large-scale collaborations between neuroscientists. The hope is that this will lead to further breakthroughs in our understanding of the complex processes that underlie decision-making and other cognitive functions.
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