How the brain changes when mastering a new skill
Research reveals new neural activity patterns that emerge with long-term learning
June 10, 2019
Science Daily/University of Pittsburgh
Researchers have discovered what happens in the brain as people learn how to perform tasks, which could lead to improved lives for people with brain injuries. The study revealed that new neural activity patterns emerge with long-term learning and established a causal link between these patterns and new behavioral abilities.
Mastering a new skill -- whether a sport, an instrument, or a craft -- takes time and training. While it is understood that a healthy brain is capable of learning these new skills, how the brain changes in order to develop new behaviors is a relative mystery. More precise knowledge of this underlying neural circuitry may eventually improve the quality of life for individuals who have suffered brain injury by enabling them to more easily relearn everyday tasks.
Researchers from the University of Pittsburgh and Carnegie Mellon University recently published an article in PNAS that reveals what happens in the brain as learners progress from novice to expert. They discovered that new neural activity patterns emerge with long-term learning and established a causal link between these patterns and new behavioral abilities.
The research was performed as part of the Center for the Neural Basis of Cognition, a cross-institutional research and education program that leverages the strengths of Pitt in basic and clinical neuroscience and bioengineering, with those of CMU in cognitive and computational neuroscience.
The project was jointly mentored by Aaron Batista, associate professor of bioengineering at Pitt; Byron Yu, associate professor of electrical and computer engineering and biomedical engineering at CMU; and Steven Chase, associate professor of biomedical engineering and the Neuroscience Institute at CMU. The work was led by Pitt bioengineering postdoctoral associate Emily Oby.
"We used a brain-computer interface (BCI), which creates a direct connection between our subject's neural activity and the movement of a computer cursor," said Oby. "We recorded the activity of around 90 neural units in the arm region of the primary motor cortex of Rhesus monkeys as they performed a task that required them to move the cursor to align with targets on the monitor."
To determine whether the monkeys would form new neural patterns as they learned, the research group encouraged the animals to attempt a new BCI skill and then compared those recordings to the pre-existing neural patterns.
"We first presented the monkey with what we call an 'intuitive mapping' from their neural activity to the cursor that worked with how their neurons naturally fire and which didn't require any learning," said Oby. "We then induced learning by introducing a skill in the form of a novel mapping that required the subject to learn what neural patterns they need to produce in order to move the cursor."
Like learning most skills, the group's BCI task took several sessions of practice and a bit of coaching along the way.
"We discovered that after a week, our subject was able to learn how to control the cursor," said Batista. "This is striking because by construction, we knew from the outset that they did not have the neural activity patterns required to perform this skill. Sure enough, when we looked at the neural activity again after learning we saw that new patterns of neural activity had appeared, and these new patterns are what enabled the monkey to perform the task."
These findings suggest that the process for humans to master a new skill might also involve the generation of new neural activity patterns.
"Though we are looking at this one specific task in animal subjects, we believe that this is perhaps how the brain learns many new things," said Yu. "Consider learning the finger dexterity required to play a complex piece on the piano. Prior to practice, your brain might not yet be capable of generating the appropriate activity patterns to produce the desired finger movements."
"We think that extended practice builds new synaptic connectivity that leads directly to the development of new patterns of activity that enable new abilities," said Chase. "We think this work applies to anybody who wants to learn -- whether it be a paralyzed individual learning to use a brain-computer interface or a stroke survivor who wants to regain normal motor function. If we can look directly at the brain during motor learning, we believe we can design neurofeedback strategies that facilitate the process that leads to the formation of new neural activity patterns."
https://www.sciencedaily.com/releases/2019/06/190610151934.htm
Recovery from brain injury, better sleep go hand in hand
December 22, 2016
Science Daily/American Academy of Neurology (AAN)
After a traumatic brain injury (TBI), people also experience major sleep problems, including changes in their sleep-wake cycle. A new study shows that recovering from these two conditions occurs in parallel.
"These results suggest that monitoring a person's sleep-wake cycle may be a useful tool for assessing their recovery after TBI," said study author Nadia Gosselin, PhD, of the University of Montréal in Québec, Canada. "We found that when someone sustained a brain injury and had not recovered a certain level of consciousness to keep them awake and aware of their surroundings, they were not able to generate a good sleep-wake cycle. But as they recovered, their quality of sleep improved."
A good sleep-wake cycle was defined as being alert and active during the day and getting uninterrupted sleep at night.
The study involved 30 people, ages 17 to 58, who had been hospitalized for moderate to severe TBI. Most of the patients were in a coma when they were admitted to the hospital and all initially received care in an intensive care unit. The injuries were caused by motor vehicle accidents for 20 people, falls for seven people, recreational or sports injuries for two people and a blow to the head for one person. They were hospitalized for an average of 45 days with monitoring for the study beginning an average of 21 days into a person's stay.
Each person was monitored daily for an average of 11 days for level of consciousness and thinking abilities using the Rancho Los Amigos scale, which ranges from 1 to 8. Each person also wore an activity monitor on their wrist so researchers could measure their sleep.
Researchers found that consciousness and thinking abilities improved hand-in-hand with measures of quality of sleep, showing a linear relationship.
One measure, the daytime activity ratio, shows percentage of activity that occurs during the day. Immediately after the injury, activity occurs throughout the day and night. The study showed that participants reached an acceptable sleep-wake cycle, with a daytime activity ratio of at least 80 percent, at the same point when they emerged from a minimally conscious state.
The participants still had inadequate sleep-wake cycles at a score of 5 on the Rancho Los Amigos scale, where people are confused and give inappropriate responses to stimuli but are able to follow simple commands. Sleep-wake cycles reached adequate levels at the same time that people reached a score of 6 on the Rancho Los Amigos scale, which is when people can give appropriate responses while still depending on outside input for direction. At that level, they can remember relearned tasks, but cannot remember new tasks.
The results were the same when researchers adjusted for the amount of time that had passed since the injury and the amount of medications they had received while they were in the ICU.
"It's possible that there are common underlying brain mechanisms involved in both recovery from TBI and improvement in sleep," said Gosselin. "Still, more study needs to be done and future research may want to examine how hospital lighting and noise also affect quality of sleep for those with TBI."
https://www.sciencedaily.com/releases/2016/12/161222095319.htm
Head injury patients show signs of faster aging in the brain
March 25, 2015
Imperial College London
People who have suffered serious head injuries show changes in brain structure resembling those seen in older people, according to a new study. The brain injury patients in this study were estimated to be around five years older on average than their real age.
Researchers at Imperial College London analysed brain scans from over 1,500 healthy people to develop a computer program that could predict a person's age from their brain scan. Then they used the program to estimate the "brain age" of 113 more healthy people and 99 patients who had suffered traumatic brain injuries.
The brain injury patients were estimated to be around five years older on average than their real age.
Head injuries are already known to increase the risk of age-related neurological conditions such as dementia later in life. The age prediction model may be useful as a screening tool to identify patients who are likely to develop problems and to target strategies that prevent or slow their decline.
"Your chronological age is not necessarily the best indicator of your health or how much longer you will live," said Dr James Cole, who led the study, from the Department of Medicine at Imperial College London. "There is a lot of interest in finding biomarkers of aging that can be used to measure a certain aspect of your health and predict future problems."
The study, published in the April issue of Annals of Neurology, used magnetic resonance imaging (MRI) to study changes in brain structure. The researchers used a machine learning algorithm to develop a computer program that could recognise age-related differences in the volume of white matter and grey matter in different parts of the brain.
The model was then used to estimate subjects' ages based on their brain scans. The study included 99 patients with traumatic brain injuries (TBI) caused by road accidents, falls or assaults, who had persistent neurological problems. The scans were taken between one month and 46 years after their injuries.
In healthy controls, the average difference between predicted age and real age was zero. In TBI patients, the difference was significantly higher, with a bigger discrepancy in patients with more severe injuries. Bigger differences in predicted age were associated with cognitive impairments such as poor memory and slow reaction times.
There was also a correlation between time since injury and predicted age difference, suggesting that these changes in brain structure do not occur during the injury itself, but result from ongoing biological processes, potentially similar to those seen in normal aging, that progress more quickly after an injury.
"Traumatic brain injury is not a static event," said Dr Cole. "It can set off secondary processes, possibly related to inflammation, that can cause more damage in the brain for years afterwards, and may contribute to the development of Alzheimer's or other forms of dementia."
The researchers believe the age prediction model could be applied not just to TBI patients, but might also be useful to screen outwardly healthy people.
"We want to do a study where we use the program to estimate brain age in healthy people, then see if the ones with 'old brains' are more likely to get neurodegenerative diseases. If it works, we could use it to identify people at high risk, enrol them in trials and potentially prescribe treatments that might stave off disease," said Dr Cole.
http://www.sciencedaily.com/releases/2015/03/150325082347.htm
Frequent 'heading' in soccer can lead to brain injury and cognitive impairment
November 29, 2011
Science Daily/Albert Einstein College of Medicine
Using advanced imaging techniques and cognitive tests, researchers have shown that repeatedly heading a soccer ball increases the risk for brain injury.
The researchers used diffusion tensor imaging (DTI), an advanced MRI-based imaging technique, on 38 amateur soccer players (average age: 30.8 years) who had all played the sport since childhood. They were asked to recall the number of times they headed the ball during the past year. (Heading is when players deliberately hit or field the soccer ball with their head.) Researchers ranked the players based on heading frequency and then compared the brain images of the most frequent headers with those of the remaining players. They found that frequent headers showed brain injury similar to that seen in patients with concussion, also known as mild traumatic brain injury (TBI).
The findings are especially concerning given that soccer is the world's most popular sport with popularity growing in the U.S., especially among children. Of the 18 million Americans who play soccer, 78 percent are under the age of eighteen. Soccer balls are known to travel at speeds as high as 34 miles per hour during recreational play, and more than twice that during professional play.
"These two studies present compelling evidence that brain injury and cognitive impairment can result from heading a soccer ball with high frequency," Dr. Lipton said. "These are findings that should be taken into consideration in planning future research to develop approaches to protect soccer players."
As there appears to be a safe range for heading frequency, additional research can help refine this number, which can then be used to establish heading guidelines. As in other sports, the frequency of potentially harmful actions in practice and games could be monitored and restricted based on confirmed unsafe exposure thresholds.
"In the past, pitchers in Little League Baseball sustained shoulder injuries at a rate that was alarming," Dr. Lipton noted. "But ongoing research has helped shape various approaches, including limits on the amount of pitching a child performs, which have substantially reduced the incidence of these injuries."
"Brain injury due to heading in children, if we confirm that it occurs, may not show up on our radar because the impairment will not be immediate and can easily be attributed to other causes like ADHD or learning disabilities," continued Dr. Lipton. "We, including the agencies that supervise and encourage soccer play, need to do the further research to precisely define the impact of excessive heading on children and adults in order to develop parameters within which soccer play will be safe over the long term."
http://www.sciencedaily.com/releases/2011/11/111129092420.htm
Veterans' brain injury examined
- January 9, 2014
Science Daily/Albert Einstein College of Medicine of Yeshiva University
Roadside bombs and other blasts have made head injury the “signature wound” of the Iraq and Afghanistan conflicts. Now, researchers are investigating the effect of repeated combat-related blast exposures on the brains of veterans with the goal of improving diagnostics and treatment.
Now, researchers at Albert Einstein College of Medicine of Yeshiva University, in cooperation with Resurrecting Lives Foundation, are investigating the effect of repeated combat-related blast exposures on the brains of veterans with the goal of improving diagnostics and treatment.
Mild traumatic brain injury can cause problems with cognition, concentration, memory and emotional control as well as post-traumatic stress disorder (PTSD). Einstein scientists are using advanced MRI technology and psychological tests to investigate the structural and biological impact of repeated head injury on the brain and to assess how these injuries affect cognitive function.
"Right now, doctors diagnose concussion purely on the basis of someone's symptoms," said Michael Lipton, M.D., Ph.D., associate director of Einstein's Gruss Magnetic Resonance Research Center. "We hope that our research will lead to a more scientifically valid diagnostic technique -- one that uses imaging to not only detect the underlying brain injury but reveal its severity. Such a technique could also objectively evaluate therapies aimed at healing the brain injuries responsible for concussions." Dr. Lipton is also associate professor of radiology, of psychiatry and behavioral sciences and of neuroscience at Einstein and medical director of MRI services at Montefiore Medical Center, the University Hospital for Einstein.
The Einstein researchers are studying 20 veterans from Ohio and Michigan who were deployed in Iraq and Afghanistan and have exhibited symptoms of repeated concussion. Twenty of the veterans' siblings or cousins without concussion are acting as controls. The researchers are using an advanced MRI-based imaging technique called diffusion tensor imaging (DTI) to identify injured brain areas.
DTI "sees" the movement of water molecules within and along axons, the nerve fibers that constitute the brain's white matter. This imaging technique allows researchers to measure the uniformity of water movement (called fractional anisotropy, or FA) throughout the brain. Abnormally low FA within white matter indicates axon damage and has previously been associated with cognitive impairment in patients with traumatic brain injury. (The researchers also use DTI in an ongoing study of amateur soccer players to assess possible brain injury from repeatedly heading soccer balls.)
The final group of veterans is scheduled to visit Einstein for testing in February 2014. Preliminary results should be available later this year.
Resurrecting Lives Foundation recruited the veterans and their family members and facilitates their visits to Einstein. The Foundation is also funding the research itself. The foundation's mission is to assist in the recovery and reintegration of veterans with Traumatic Brain Injury (TBI) from Operation Iraqi Freedom and Operation Enduring Freedom.
"At Resurrecting Lives Foundation, we honor our fallen heroes by caring for their brothers and sisters who return," said Chrisanne Gordon, M.D., founder and chairwoman of the foundation. "The research Dr. Lipton and his team are conducting will help us fulfill this mission."
http://www.sciencedaily.com/releases/2014/01/140109124941.htm