Category: neurobiology

Scientists Just Used Brain Stimulation to Literally Change How People Think

Hitting the Right Lobes

A team of researchers from Boston University (BU) has explored the possibility of enhancing a person’s ability to learn and control their behavior — in short, to change how people think — by stimulating the brain. BU researcher Robert Reinhart used a new form of brain stimulation, called high-definition transcranial alternating current stimulation (HD-tACS), to “turbo charge” two brain regions that influence how we learn.

“If you make an error, this brain area fires. If I tell you that you make an error, it also fires. If something surprises you, it fires,” Reinhart said in a BU Research press release, referring to the medial frontal cortex, which he calls the “alarm bell of the brain.”

A scan of a brain involved in the study shows how brain stimulation lights up the medial frontal cortex and prefrontal cortex, both involved in how people learn.
The brain’s right hemisphere was more involved in changing behavior. Image credit: Robert Reinhart/Boston University

Reinhart and his colleagues found that stimulating this region, as well as the lateral prefrontal cortex, could change how a person learns. “These are maybe the two most fundamental brain areas involved with executive function and self-control,” he added.

In a study published in the journal of the Proceedings of the National Academy of Sciences (PNAS), Reinhart’s team described how applying electrical stimulation using HD-tACS quickly and reversibly increased or decreased a healthy person’s executive function, which led to a change in behavior.

Smart Charge

Reinhart’s team tested 30 healthy people, each wearing a soft cap with electrodes that conveyed the stimulation. The test was simple: each subject had to press a button every 1.7 seconds. In the first three rounds of tests, the researchers either cranked up the synchronicity between the two lobes, disrupted it, or did nothing.

The participants’ brain activity, monitored with an electroencephalogram (EEG), showed statistically significant results. When the brain waves were upped, the subjects learned faster and made fewer mistakes, which they corrected abruptly. When it was disrupted, they made more errors and learned more slowly. 

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What was even more surprising was when 30 new participants took an adjusted version of the test. This group started with their brain activity temporarily disrupted, but then received stimulation in the middle of the activity. The participants quickly recovered their original brain synchronicity levels and learning behavior. “We were shocked by the results and how quickly the effects of the stimulation could be reversed,” says Reinhart.

Although their study still leaves much to learn, the BU team was actually the first to identify and test how the millions of cells in the medial frontal cortex and the lateral prefrontal cortex communicate with each other through low frequency brain waves. “The science is much stronger, much more precise than what’s been done earlier,” said David Somers, a BU brain sciences and psychology professor who wasn’t part of the study.

The bigger question, Somers noted, is how far a person can go with such a technology. Who doesn’t want to have their brain performance enhanced? This could produce the same effects as nootropics or smart drugs, but with fewer potential side effects, as the brain is stimulated directly. Having access to such a technology could be a game changer — but just as with smart drugs, there’s the question of who should have access to such a technology.

The post Scientists Just Used Brain Stimulation to Literally Change How People Think appeared first on Futurism.

Neuroscientists Say Forgetting Things May Be an Essential Part of Our Brain Function

The Usefulness of Forgetting

We’ve all had moments of forgetfulness, and not infrequently the act of forgetting about something can have a negative impact on our day — or even our lives. Some even consider being forgetful to be a sign of damage in the brain, particularly the area tasked with storing and retaining information. While this may be true in the case of memory disorders, Canadian neuroscientists from the University of Toronto propose that the typical moments of forgetfulness with which most of us are familiar are actually the brain’s way of making us smarter — and that those moments may even make our lives better.

In a study published in the journal Neuron, researchers offered an alternative hypothesis as to why the brain purposefully works to forget information. Though not entirely a new field of study, the neurobiology of forgetting has been relatively unexamined, as co-author Blake Richards explained during an interview with NPR’s Andrea Hsu.

“Generally, the focus for the last few decades in neuroscience has been the question of how do the cells in our brains change themselves in order to store information and remember things.”

Their research found that the brain’s ability to store huge amounts of information can often be hindered by keeping memories that may be irrelevant for our everyday existence. “In fact, I would argue they’re not just irrelevant, but they can be detrimental to living our daily lives,” Richards said. Information that isn’t necessary for us to evolve and survive, then, isn’t necessary for the brain to retain.

“Our memories ultimately are there to help us make decisions, to act in the world in an intelligent manner,” Richards went on to explain. “Evolution cares about whether or not you are an individual who’s making appropriate decisions in the environment to maximize your chances of survival.”

Memory and Artificial Intelligence

Researchers argue that forgetting is actually a function of memory. Ironic, right? But when you think about it, it actually makes a lot of sense.

“[W]hen the goal of memory is to help you make intelligent decisions in a complex, changing world, then the best memory system will be a memory system that forgets some stuff. So a healthy, properly functioning memory system is one that does engage in some degree of forgetting.”

Much of Richard’s work on memory and forgetfulness is thanks to his application of theories on artificial intelligence (AI) and how the brain learns. He said that in the world of AI there’s a phenomenon called over-fitting, where a machine ends up storing so much information that it hinders its ability to make intelligent decisions.

Richards hopes that by understanding the neurobiology of forgetting, we’ll be able to design AI systems capable of interacting with the world and making decisions the same way human beings do. Luckily, there are many studies currently focused on trying to make AI systems — or artificial neural networks — behave like human brains. One crucial aspect we’re still working on is how to facilitate memory development in AI. By understanding the nuances of human memory, it may be possible to design AI systems that distinguish between information that’s trivial — and what’s necessary for survival.

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A Brain in a Dish: 3D Mini-Brains Prove to Be Remarkably Accurate

Better Brain Models

When it comes to building model organs, perhaps none requires as much precision and exactness in detail as the human brain. In an effort to improve upon existing models, scientists at the Salk Institute studied a 3D “mini-brain” model grown from human stem cells. They concluded that it was more similar to human brains, both structurally and functionally, than the 2D models currently in use.

Just three years ago, European researchers came up with a method of growing embryonic brain cells in 3D gels, which allowed the cells to differentiate into realistic layers similar to those of a real human brain. These 3D models are called cerebral organoids (CO), and according to Joseph Ecker, director of Salk’s Genomic Analysis Laboratory, “Being able to grow human brain cells as miniature three-dimensional organs was a real breakthrough.”

However, until Ecker and his colleagues conducted their recent study, published in the December 20 issue of Cell Reportsno one knew just how accurately these COs mimicked real brains.

Better Brain Research

To figure out just how realistic these 3D brains were, Ecker’s team studied COs in early stages of brain development and compared them to actual human brains in similar developmental stages. The COs Ecker and his team used were from a human embryonic cell line called H9. With the right chemicals, H9 was induced down a neurodevelopmental pathway for 60 days.

Credits: Madeline Lancaster/MRC-LMB (Medical Research Council, Laboratory of Molecular Biology), UK
Credits: Madeline Lancaster/MRC-LMB (Medical Research Council, Laboratory of Molecular Biology), UK

They studied the COs epigenomes — basically, the chemical compounds that tell a genome what to do — because these have been increasingly associated with the development of brain diseases such as schizophrenia. After comparing their results with age-matched real tissues from the National Institutes of Health NeuroBioBank and with 2D brain-model data from other researchers, they saw that COs were more like authentic brains than their 2D counterparts and seemed to grow following the same early-developmental timelines as real brains.

“No one has done epigenome sequencing for cerebral organoids before,” said author Chongyuan Luo, research associate at Salk. “This kind of assessment is so important for understanding brain development, especially if we’re eventually going to use these tissues for neurological therapies.”

With a model that’s closer to a real brain, scientists will be better equipped to study brain development and its role in the emergence of neurological diseases such as Alzheimer’s or schizophrenia, putting us one step closer to improved treatment options or even cures.

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