HMN 2025: How A unified idea of the thoughts could possibly be key to understanding mind operate and neurological illness

In a brand new paper with implications for stopping Alzheimer’s illness and different neurological problems, Keith Hengen, an affiliate professor of biology in Arts & Sciences at Washington University in St. Louis, suggests a brand new complete strategy to understanding how the mind works and the foundations it should comply with to achieve optimum efficiency.

“There’s a standard notion that the human mind is probably the most difficult factor within the universe,” Hengen stated. “The mind is immensely highly effective, however that energy could come up from a comparatively easy set of mathematical ideas.”

Hengen begins with the premise that just about all the things our brains do is discovered or powerfully formed by {experience}. In different phrases, we aren’t born with hard-wired circuits preprogrammed to assist us learn, drive automobiles or do anything that we do day-after-day. A wholesome mind have to be able to be taught something and all the things.

But how is a group of neurons able to {learning}? Hengen means that brains turn into {learning} machines solely once they attain a particular state referred to as “criticality.” An idea borrowed from physics, criticality describes a posh system that’s on the tipping mark between order and chaos. At this razor’s edge, brains are primed to achieve new info, Hengen stated. “Brains want to achieve criticality to suppose, bear in mind and be taught.”

Hengen proposed criticality as a unifying idea of mind operate and illness within the journal Neuron. Woodrow Shew, a physicist on the University of Arkansas, is the co-author.

A biologist and a physicist could look like an odd pairing, however the brand new unifying idea blends each realms of science. Physicists typically describe criticality utilizing the traditional instance of a sand pile: As sand is added, the pile will develop steeper and steeper till it will definitely avalanches. Right earlier than that last grain triggered a brief time period of chaos, the pile was at a crucial angle, one step away from instability.

Shew defined that physicists first developed a deep understanding of criticality as a option to describe magnets and different supplies. Around the flip of the twenty first century, these concepts have been expanded to clarify a broader vary of advanced techniques, together with avalanches, earthquakes and, finally, residing techniques and the mind.

A defining facet of crucial techniques is that they give the impression of being the identical at any scale: A sand pile getting ready to an avalanche has the identical slope whether or not the pile is tiny or mountainous. In the mind, criticality is fixed whether or not it is measured in a handful of neurons or a whole area. Likewise, mind patterns that unfold in time are startlingly comparable when thought of in milliseconds or hours. “This matches our intuitive understanding of how brains work,” Hengen stated. “Our inside experiences span milliseconds to months. They haven’t got a scale.”

Hengen and Shew counsel that criticality is not only a theoretical idea; it is a state that may be exactly measured and calculated by way of fMRI mind imaging know-how. “Criticality is the optimum computational state of the mind,” Hengen stated. “We’ve developed a mathematical option to measure how shut the mind is to criticality, which ought to assist us nail down the elemental questions on how a human mind works.”

A brand new understanding of illness

The criticality framework presents a brand new perspective for understanding neurological illness. Rather than specializing in particular broken mind areas or amassed proteins, Hengen argues that illnesses akin to Alzheimer’s destroy one thing extra fundamental: the mind’s capability to take care of criticality.

“Alzheimer’s and different neurodegenerative illnesses do not simply injury neurons, they break the mind’s basic capability to compute by slowly dissolving criticality,” Hengen defined. “As a mind strikes additional and farther from criticality, it loses the flexibility to adapt and course of info successfully.”

This framework explains a puzzling function of mind illnesses: Patients typically seem utterly regular till they’ve misplaced many neurons. “The mind has outstanding compensatory skills that may masks purposeful issues whilst criticality begins to erode,” Hengen stated. “Traditional assessments miss the early levels as a result of they give attention to established endpoints that the mind tries to take care of by way of workarounds.”

As criticality step by step deteriorates, the mind works more durable to realize the identical cognitive outcomes, Hengen stated. “It’s like an engine that also runs however requires extra gasoline and generates extra warmth. By the time we discover reminiscence issues or different signs, criticality has possible been compromised for years.”

Hengen’s collaboration with David M. Holtzman, MD, the Barbara Burton and Reuben M. Morriss III Distinguished Professor at WashU Medicine, has revealed that tau protein buildup in Alzheimer’s immediately disrupts criticality, offering a transparent hyperlink between the illness’s molecular hallmarks and cognitive collapse.

This connection between criticality and Alzheimer’s opens thrilling diagnostic potentialities. In idea, a easy fMRI might assist detect breakdowns in criticality years earlier than signs seem. “In mixture with cutting-edge blood exams, we might establish individuals in danger and intervene earlier than irreversible injury happens,” Hengen stated.

In one other collaboration, Hengen has teamed up with Deanna Barch, the Gregory B. Couch Professor of Psychiatry at WashU Medicine and a professor of psychological and mind sciences in Arts & Sciences, for an observational study to see how criticality at delivery determines cognitive improvement and talents in childhood.

“From the start, some youngsters are nearer to criticality than others, which, based mostly on our idea, suggests they’ll be higher learners,” Hengen stated. “Many exterior components can have an effect on their success in class, however criticality can clarify a powerful quantity of the variability between kids.”

The sleep-mind connection

In early 2024, Hengen and co-author Ralf Wessel, a professor of physics in Arts & Sciences at WashU, used the idea of criticality to revisit an age-old query: Why do we’d like sleep? By monitoring mind exercise over a number of weeks, they discovered that sleep restores a state of criticality. “Being awake and energetic strikes us away from criticality, and sleep is sort of a reset button,” Hengen defined.

That perception might assist researchers unlock the facility of sleep as a remedy for Alzheimer’s and different neurological illnesses that push the mind away from its optimum state. Previous research by Holtzman and others have discovered that individuals who do not get the sleep they want—maybe as a result of shift work or persistent insomnia—are at a a lot larger threat for Alzheimer’s as they age. And there’s already some evidence that sleep interventions may also help gradual the development of Alzheimer’s signs.

Hengen believes that focused, intensive sleep-based remedy might assist restore criticality and enhance {learning} and reminiscence in individuals with mind illness. Studies of mice carried out by Holtzman and James McGregor, a postdoctoral researcher in Hengen’s lab, provide a glimpse of the chances: Mice particularly bred to have signs of Alzheimer’s turn into sooner learners after a focused sleep intervention reinforces criticality.

Critical future

There is way work to be achieved, however Hengen would ultimately like to know how criticality helps clarify advanced options of human neurobiology. “We could discover that somebody who’s an incredible artist, for instance, could be extraordinarily near criticality in components of the mind concerned in artistic ideation,” he stated. It’s additionally attainable {that a} shut have a look at criticality might mark to undiscovered tendencies or skills that simply want an outlet. “Maybe they by no means tried artwork, however we will see that the potential is there.”

In the meantime, Hengen, Shew, and others are spreading the phrase concerning the significance of criticality. Hengen offered a TEDx discuss on the topic in 2024 and shared his work at Arts & Sciences’ inaugural research pitch competition, where he took second place. He hopes the brand new Neuron paper will encourage conversations amongst neurologists, docs, reporters and most people.

A unified idea of the thoughts might change the world, however first, it should unify the specialists. “Woody (Shew) and I actually suppose we’re on to one thing right here,” Hengen stated. “And, maybe slowly, others are beginning to agree.”

WashU was the best place for a brand new idea of the mind to emerge, Hengen stated. “We’re surrounded by sensible individuals in various fields, together with physics, biology, psychology, arithmetic and neuroscience, and the group right here is remarkably supportive,” he stated. “Everyone is able to assist.”