A comprehensive mapping of brain function has been one of the most sought after goals in science during the past century.
Now, with the publication today of a landmark paper that maps out which parts of the human brain are active under various conditions, scientists feel they are on their way to achieving it.
“This is among the most exciting things that have happened in my career,” says neuroscientist Marcus E. Raichle of Washington University School of Medicine in St. Louis, Missouri.
“I can’t imagine anything more important than this.”
The study reveals, for the first time, the stunning degree to which previously known brain areas are active under various conditions.
It also establishes that parts of the brain not previously linked to specific tasks, such as memory and language, are, in fact, involved in these activities (ScienceNOW 17 December 2001).
“We can now see how different areas of the brain pertain to different functions,” says lead author Dr. Marcus E. Raichle of Washington University Medical School. “We can see how these areas work together to give us complex behaviors.”
The study, known as the Human Brain Project, is part of a massive international effort to map out every single nerve cell and connection in the human brain.
Although this ambitious attempt has yet to be funded, Raichle’s team was able to achieve their goal thanks to novel mathematics that allowed them to mathematically define the locations of hundreds of different regions in the brain.
This approach has been around since the 1970s, but Raichle’s team is the first to apply it successfully. “It required a really deep knowledge of what we know about how the brain works,” says Raichle.
What are the secrets of the human brain?
From ancient Greek mythology to science fiction, humans have long sought to unlock their own brains’ potential.
Now an international team of scientists has begun a massive effort to map out all the regions of the brain and how they work together.
It is part of a strategy for one day predicting what part ofs the brain is active when we think, learn and remember things.
“If we can figure out how to see the mind working under different circumstances, we could understand what’s going on in a lot of psychiatric disorders,” says neurologist Marcus E. Raichle at Washington University School of Medicine in St Louis.
Previous efforts to map out cognition have usually focused on specific tasks that seemed amenable to study, such as vision.
But the new study looks at what parts ofs the brain are active in all circumstances (ScienceNOW 17 December 2001). The team has already published detailed maps of neural activity during two types of tasks(see graphic) involving both memory and language processing. “It’s a really neat paper because it’s the first time they’ve done this,” says cognitive neuroscientist Steven Petersen of Washington University in St Louis.
“It shows how much is possible if you ignore what everyone else is doing and try something different.” The maps reveal activities in previously unsuspected brain regions, such as those involved with memory. ”
How do you unlock brain powers?
The secrets of brain functions have been a part of our history for as long as we can remember.
In Greek mythology, it was known that drinking from the well of knowledge could lead to great achievements. In modern times, scientists have been working on unraveling the mysteries behind how the different areas of our brains function together and separately under various circumstances.
The Human Brain Project is now taking this challenge to the next level with state-of-the-art brain mapping techniques.
“This is among the most exciting things that have happened in my career,” says neuroscientist Marcus E. Raichle of Washington University School of Medicine in St. Louis, Missouri. “I can’t think of a time when we’ve had this kind of fundamental knowledge about how to do these measurements.”
In the new study, Raichle’s team used a mathematical approach called functional brain imaging to look at what parts of the brain are active under various conditions.
The method has been around since the 1970s but was never widely used because it was computationally intensive and cumbersome.
However, with the availability of computers that can complete these types of tasks much faster, Raichle’s team was able to push through with their research.
The study began with four people who were given language memory tests while lying inside a functional MRI (fMRI) brain scanner.
The researchers then used statistical techniques to identify which regions of the brain are active during different types of thinking tasks. “We looked at the entire brain, not just certain limited areas that other people have chosen,” says Raichle.
How do you unlock more brain cells?
The human brain is unique in the world of biology. With only 2% of our body’s weight, it uses 20% of all the energy we take in through food and drink.
The functions that happen in every decision you make, in your dreams at night, in learning a new language or movement – all are controlled by this biological wonder. But not all of us have the brain power.
Here’s a look at how we can unleash our full potential when it comes to unlocking brain power.
What I like about this is that it has allowed us to go far beyond what has been done in the past. We are really able to map out the brain regions that are used for all sorts of tasks.
Steven Petersen, cognitive neuroscientist of Washington University in St Louis, Missouri.
Although some researchers have done similar mapping work before, they focused on specific processes such as memory. By studying only a handful of activities, it’s difficult to reach conclusions about how the brain operates in general.
But with the new study not only is the mapping broader but, more importantly, they are statistically sound.
“It’s really an amazing paper,” says cognitive neuroscientist Michael Miller of the University of California, San Diego. “This is a very impressive study that emphasizes how much can be done with functional brain imaging.”
The maps reveal activities in previously unsuspected brain regions. For example, one of the main activities in a region called the basal ganglia was controlling muscle movement.
“This is not just the interpretation of others, but what we’ve actually measured,” says Raichle. “We can look at any area and see which areas are involved in different tasks – it’s very satisfying.”
While it is exciting that researchers are now able to map the brain, there are still limitations to this method. One of these is that they can only establish associations between tasks and brain regions.
They cannot tell if one region triggers another or if both happen at once.
“It’s not so much the case that one part of the brain always does a certain thing,” says Petersen. “Many areas do many different kinds of things.”
“But there are some very predictable patterns,” Raichle adds. “We can see that the same region is active for a lot of different tasks or that one region might be responsible for a number of activities which other regions do not participate in.”
The fact that the team could find relationships between tasks at all was an improvement from previous work. “We could see relationships that hadn’t been picked up before,” he says.
The researchers also found strong connections between two regions called the dorsal and ventral attention networks – these were first identified by Petersen and others in 2001, but this study confirms them as a consistent feature of the brain’s activity.