Posts tagged motor skills
Articles and news from the latest research reports.
Study says we’re over the hill at 24
It’s a hard pill to swallow, but if you’re over 24 years of age you’ve already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study.
SFU’s Joe Thompson, a psychology doctoral student, associate professor Mark Blair, Thompson’s thesis supervisor, and Andrew Henrey, a statistics and actuarial science doctoral student, deliver the news in a just-published PLOS ONE Journal paper.
In one of the first social science experiments to rest on big data, the trio investigates when we start to experience an age-related decline in our cognitive motor skills and how we compensate for that.
The researchers analyzed the digital performance records of 3,305 StarCraft 2 players, aged 16 to 44. StarCraft 2 is a ruthless competitive intergalactic computer war game that players often undertake to win serious money.
Their performance records, which can be readily replayed, constitute big data because they represent thousands of hours worth of strategic real-time cognitive-based moves performed at varied skill levels.
Using complex statistical modeling, the researchers distilled meaning from this colossal compilation of information about how players responded to their opponents and more importantly, how long they took to react.
“After around 24 years of age, players show slowing in a measure of cognitive speed that is known to be important for performance,” explains Thompson, the lead author of the study, which is his thesis. “This cognitive performance decline is present even at higher levels of skill.”
But there’s a silver lining in this earlier-than-expected slippery slope into old age. “Our research tells a new story about human development,” says Thompson.
“Older players, though slower, seem to compensate by employing simpler strategies and using the game’s interface more efficiently than younger players, enabling them to retain their skill, despite cognitive motor-speed loss.”
For example, older players more readily use short cut and sophisticated command keys to compensate for declining speed in executing real time decisions.
The findings, says Thompson, suggest “that our cognitive-motor capacities are not stable across our adulthood, but are constantly in flux, and that our day-to-day performance is a result of the constant interplay between change and adaptation.”
Thompson says this study doesn’t inform us about how our increasingly distracting computerized world may ultimately affect our use of adaptive behaviours to compensate for declining cognitive motor skills.
But he does say our increasingly digitized world is providing a growing wealth of big data that will be a goldmine for future social science studies such as this one.
Hitting the perfect tennis serve requires hours and hours of practice, but for scientists who study complex motor behaviors, there always has been a large unanswered question — what is the brain learning from those hours spent on the court? Is it simply the timing required to hit the perfect serve, or is it the precise path along which to move the hand?
The answer, Harvard researchers say, is both — but in separate circuits.
Bence Ölveczky, the John L. Loeb Associate Professor of the Natural Sciences, has found that the brain uses two largely independent neural circuits to learn the temporal and spatial aspects of a motor skill. The study is described in a Sept. 26 paper in Neuron.
“What we’re studying is the structure of motor-skill learning,” Ölveczky said. “What we were able to show is that the brain divides something that’s complex into modules — in this case for timing and for motor implementation — as a way to take advantage of the hierarchical structure of the motor system, and it imprints learning at the different levels independently.”
To tease out how those independent circuits operate, Ölveczky and his colleagues turned to a creature well-known for its ability to learn — the zebra finch. The tiny birds are regularly used in studies of learning because each male learns to sing a unique song from its father.
In a series of experiments, Ölveczky’s team used traditional conditioning techniques to change the timing of a bird’s song by speeding up or slowing down certain “syllables” in the song. They could also change which vocal muscles were activated and have the bird sing at a higher or lower pitch.
“But when you change the pitch of a syllable, the duration doesn’t change, and when you change the duration the pitch doesn’t change,” Ölveczky said. “It appears the neural circuits for the two features are separate.”
Additional evidence that the circuits for learning motor implementation and timing are distinct came when researchers lesioned the basal ganglia of the birds — the region of the brain long thought to play a critical role in song learning.
“The thinking had been that there was one circuit for song-learning in general,” Ölveczky said. “We found that if we lesioned the basal ganglia and repeated the pitch-shift experiment, the bird could no longer use the information it got from our feedback to change its behavior — in other words, it couldn’t learn.”
Experiments aimed at changing the birds’ timing, however, were just as effective, suggesting two separate learning circuits — with only one involving the basal ganglia.
Such independence and modularity is critical, Ölveczky said, because it allows different features of a behavior to be modified independently if circumstances change. Parallel learning of different features can also speed up the learning process and enable the flexibility we see in birdsong and many human motor skills.
“If you learn something — it could be your tennis serve, or it could be any behavior — and you need to slow it down or speed it up to fit some new contingency, you don’t have to completely re-learn the whole thing, you can just change the timing, and everything else will remain exactly the same.
“In fact, ‘slow practice,’ a technique used by many piano and dance teachers, makes good use of this modularity,” Ölveczky said. “Students are first taught to perform the movements of a piece slowly. Once they have learned it, all they need to do is get the timing right. The technique works because the two processes — motor implementation and timing — do not interfere with each other.”
The hope among researchers, Ölveczky said, is that a better understanding of how birds learn complex motor tasks such as singing unique songs will help shed new light on the neural underpinnings of learning in humans.
“For us, this is inspiration to look at similar types of questions in mammals,” he said. “The flexibility with which we can alter the spatial and temporal structure of our motor output is similar to songbirds, but our understanding of how the mammalian brain implements the underlying learning process is not anywhere near as advanced as for songbirds. The intriguing parallels in both circuitry and behavior, however, suggest a general principle of how the brain parses the motor skill learning process.”
Children with delayed motor skills struggle more socially
Studies have shown that children with autism often struggle socially and now new research suggests that a corresponding lack of motor skills – including catching and throwing – may further contribute to that social awkwardness.
The findings, published in the July issue of Adapted Physical Activity Quarterly, add to the growing body of research highlighting the link between autism and motor skill deficits.
Lead author Megan MacDonald is an assistant professor in the College of Public Health and Human Sciences at Oregon State University. She is an expert on the movement skills of children with autism spectrum disorder.
In the study, researchers looked a group of young people ages 6 to 15 diagnosed with autism spectrum disorder. All 35 of the students were considered high-functioning and attended typical classrooms. The researchers looked at two types of motor skills – “object-control” motor skills, which involve more precise action such as catching or throwing – and “locomotion” skills, such as running or walking. Students who struggled with object-control motor skills were more likely to have more severe social and communication skills than those who tested higher on the motor skills test.
“So much of the focus on autism has been on developing social skills, and that is very crucial,” MacDonald said. “Yet we also know there is a link between motor skills and autism, and how deficits in these physical skills play into this larger picture is not clearly understood.”
Developing motor skills can be crucial for children because students often “mask” their inability to participate in basic physical activities. A student with autism may not be participating on the playground because of a lack of social skills, but the child may also be unsure of his or her physical ability to play in these activities.
“Something which seems as simple as learning to ride a bike can be crucial for a child with autism,” MacDonald said. “Being able to ride a bike means more independence and autonomy. They can ride to the corner store or ride to a friend’s house. Those kind of small victories are huge.”
She said the ability to run, jump, throw and catch isn’t just for athletic kids – physical activity is linked not only to health, but to social skills and mental well-being.
“I often show people photos of what I like to do in my spare time – canoeing, hiking, snowshoeing, and then point out that these require relatively proficient motor skills,” she said. “But that is not why I do those things. I’m doing it because I’m with my friends and having fun.”
MacDonald said the positive news for parents and educators is that motor skills can be taught.
“We have programs and interventions that we know work, and have measurable impact on motor skill development,” MacDonald said. “We need to make sure we identify the issue and get a child help as early as possible.”
(Source: oregonstate.edu)
New tasks become as simple as waving a hand with brain-computer interfaces
Small electrodes placed on or inside the brain allow patients to interact with computers or control robotic limbs simply by thinking about how to execute those actions. This technology could improve communication and daily life for a person who is paralyzed or has lost the ability to speak from a stroke or neurodegenerative disease.
Now, University of Washington researchers have demonstrated that when humans use this technology – called a brain-computer interface – the brain behaves much like it does when completing simple motor skills such as kicking a ball, typing or waving a hand. Learning to control a robotic arm or a prosthetic limb could become second nature for people who are paralyzed.
“What we’re seeing is that practice makes perfect with these tasks,” said Rajesh Rao, a UW professor of computer science and engineering and a senior researcher involved in the study. “There’s a lot of engagement of the brain’s cognitive resources at the very beginning, but as you get better at the task, those resources aren’t needed anymore and the brain is freed up.”
Rao and UW collaborators Jeffrey Ojemann, a professor of neurological surgery, and Jeremiah Wander, a doctoral student in bioengineering, published their results online June 10 in the Proceedings of the National Academy of Sciences.
In this study, seven people with severe epilepsy were hospitalized for a monitoring procedure that tries to identify where in the brain seizures originate. Physicians cut through the scalp, drilled into the skull and placed a thin sheet of electrodes directly on top of the brain. While they were watching for seizure signals, the researchers also conducted this study.
The patients were asked to move a mouse cursor on a computer screen by using only their thoughts to control the cursor’s movement. Electrodes on their brains picked up the signals directing the cursor to move, sending them to an amplifier and then a laptop to be analyzed. Within 40 milliseconds, the computer calculated the intentions transmitted through the signal and updated the movement of the cursor on the screen.
Researchers found that when patients started the task, a lot of brain activity was centered in the prefrontal cortex, an area associated with learning a new skill. But after often as little as 10 minutes, frontal brain activity lessened, and the brain signals transitioned to patterns similar to those seen during more automatic actions.
“Now we have a brain marker that shows a patient has actually learned a task,” Ojemann said. “Once the signal has turned off, you can assume the person has learned it.”
While researchers have demonstrated success in using brain-computer interfaces in monkeys and humans, this is the first study that clearly maps the neurological signals throughout the brain. The researchers were surprised at how many parts of the brain were involved.
“We now have a larger-scale view of what’s happening in the brain of a subject as he or she is learning a task,” Rao said. “The surprising result is that even though only a very localized population of cells is used in the brain-computer interface, the brain recruits many other areas that aren’t directly involved to get the job done.”
Several types of brain-computer interfaces are being developed and tested. The least invasive is a device placed on a person’s head that can detect weak electrical signatures of brain activity. Basic commercial gaming products are on the market, but this technology isn’t very reliable yet because signals from eye blinking and other muscle movements interfere too much.
A more invasive alternative is to surgically place electrodes inside the brain tissue itself to record the activity of individual neurons. Researchers at Brown University and the University of Pittsburgh have demonstrated this in humans as patients, unable to move their arms or legs, have learned to control robotic arms using the signal directly from their brain.
The UW team tested electrodes on the surface of the brain, underneath the skull. This allows researchers to record brain signals at higher frequencies and with less interference than measurements from the scalp. A future wireless device could be built to remain inside a person’s head for a longer time to be able to control computer cursors or robotic limbs at home.
“This is one push as to how we can improve the devices and make them more useful to people,” Wander said. “If we have an understanding of how someone learns to use these devices, we can build them to respond accordingly.”
The research team, along with the National Science Foundation’s Engineering Research Center for Sensorimotor Neural Engineering headquartered at the UW, will continue developing these technologies.
CI Therapy Produces Increase in Grey Matter in Brains of Children with Cerebral Palsy
Researchers at the University of Alabama at Birmingham (UAB) report that children with cerebral palsy who underwent Constraint Induced Movement therapy (CI therapy) saw a significant increase in grey matter volume in areas of the brain associated with movement. The findings, published online April 22, 2013 in Pediatrics, are the first to show that structural remodeling of the brain occurs during rehabilitation in a pediatric population.
“It is well understood that CI therapy produces a re-wiring of the brain, leading to functional improvement in motor skills in children and adults who have experienced a brain injury,” said Edward Taub, Ph.D., the developer of CI therapy and a study co-author. “This study reinforces the idea that CI therapy also remodels the brain, producing a real, physical change in the brain.”
Grey matter is a component of the central nervous system, consisting primarily of neuronal cell bodies, glial cells and dendrites. The study examined ten children with cerebral palsy, between the ages of 2 and 7, who underwent a three week course of CI therapy. Changes in grey matter were assessed with a technique called voxel-based morphometry (VBM), performed on images acquired through magnetic resonance imaging.
“We saw increases in grey matter volume in the sensorimotor cortices on both sides of the brain and in the hippocampus,” said Chelsey Sterling, M.A., a graduate student in medical psychology and first author of the study. “These increases were accompanied by large improvements in spontaneous arm use in the home environment. Notably, increases in grey matter correlated with improvement in motor activity.”
Sterling says the significant correlation between increases in grey matter volume and magnitude of motor improvement raises the possibility of a causal relationship.
The researchers suggest the observed increase in grey matter could be due to one or more different processes, including an increase in synaptic density, the creation of new neurons or glial cells or the establishment of new blood vessels within the brain.
“An increase in grey matter is indicative that the brain is capable of supporting increased motor activity and function,” said Gitendra Uswatte, Ph.D., a study co-author. “Along with the improvements observed in the dexterity and everyday use of the arm that was the target of rehabilitation, this is a strong indication that a child with cerebral palsy can have substantial gains in motor function when provided with the correct stimulation.”
VBM analysis was performed three weeks prior to therapy, at the beginning of therapy and at the end of the three week therapy period. The authors say that no significant grey matter change was seen during the three weeks before treatment.
The children underwent intensive motor training for three hours each weekday for a three week period in which the child’s less-affected arm was continuously restrained in a long arm cast. Each child’s caregiver received a transfer package, which included steps to induce continuation of use of the more-affected arm at home. The MRI scans were performed at Children’s of Alabama.
Taub, a university professor in the Department of Psychology, developed the family of techniques called CI therapy. The therapy has been shown to be effective in improving the rehabilitation of movement after stroke and other neurological injuries in both children and adults.
“The motor improvement and changes in grey matter following CI therapy observed in this study are similar to those observed previously in adults,” said Taub. “It is further evidence that the brain has a remarkable capacity to heal itself when presented with an efficacious rehabilitation intervention such as CI therapy.”
Motor skills research nets good news for middle-aged
People in their 20s don’t have much on their middle-aged counterparts when it comes to some fine motor movements, researchers from UT Arlington have found.
In a simple finger-tapping exercise, study participants’ speed declined only slightly with age until a marked drop in ability with participants in their mid-60s.
Priscila Caçola, an assistant professor of kinesiology at The University of Texas at Arlington, hopes the new work will help clinicians identify abnormal loss of function in their patients. Though motor ability in older adults has been studied widely, not a lot of research has focused on when deficits begin, she said.
The journal Brain and Cognition will include the study in its June 2013 issue. It is already available online.
“We have this so-called age decline, everybody knows that. I wanted to see if that was a gradual process,” Caçola said. “It’s good news really because I didn’t see differences between the young and middle-aged people.”
Caçola’s co-authors on the paper are Jerroed Roberson, a senior kinesiology major at UT Arlington, and Carl Gabbard, a professor in the Texas A&M University Department of Health and Kinesiology.
The researchers based their work on the idea that before movements are made, the brain makes a mental plan. They used an evaluation process called chronometry that compares the time of test participants’ imagined movements to actual movements. Study participants – 99 people ranging in age from 18 to 93 – were asked to imagine and perform a series of increasingly difficult, ordered finger movements. They were divided into three age groups – 18-32, 40-63 and 65-93 – and the results were analyzed.
“What we found is that there is a significant drop-off after the age of 64,” Roberson said. “So if you see a drop-off in ability before that, then it could be a signal that there might be something wrong with that person and they might need further evaluation.”
The researchers also noted that the speed of imagined movements and executed actions tended to be closely associated within each group. That also could be useful knowledge for clinicians, the study said.
“The important message here is that clinicians should be aware that healthy older adults are slower than younger adults, but are able to create relatively accurate internal models for action,” the study said.
Caçola is a member of UT Arlington Center for Health Living and Longevity. She has published previous research on the links between movement representation and motor ability in children.
What You Hear Could Depend on What Your Hands are Doing
A new finding could lead to strategies for treating speech loss after a stroke and helping children with dyslexia.
New research links motor skills and perception, specifically as it relates to a second finding—a new understanding of what the left and right brain hemispheres “hear.” Georgetown University Medical Center researchers say these findings may eventually point to strategies to help stroke patients recover their language abilities, and to improve speech recognition in children with dyslexia.
The study, presented at Neuroscience 2012, the annual meeting of the Society for Neuroscience, is the first to match human behavior with left brain/right brain auditory processing tasks. Before this research, neuroimaging tests had hinted at differences in such processing.
“Language is processed mainly in the left hemisphere, and some have suggested that this is because the left hemisphere specializes in analyzing very rapidly changing sounds,” says the study’s senior investigator, Peter E. Turkeltaub, M.D., Ph.D., a neurologist in the Center for Brain Plasticity and Recovery. This newly created center is a joint program of Georgetown University and MedStar National Rehabilitation Network.
Turkeltaub and his team hid rapidly and slowly changing sounds in background noise and asked 24 volunteers to simply indicate whether they heard the sounds by pressing a button.
“We asked the subjects to respond to sounds hidden in background noise,” Turkeltaub explained. “Each subject was told to use his or her right hand to respond during the first 20 sounds, then the left hand for the next 20 second, then right, then left, and so on.”
He says when a subject was using their right hand, they heard the rapidly changing sounds more often than when they used their left hand, and vice versa for the slowly changing sounds.
“Since the left hemisphere controls the right hand and vice versa, these results demonstrate that the two hemispheres specialize in different kinds of sounds—the left hemisphere likes rapidly changing sounds, such as consonants, and the right hemisphere likes slowly changing sounds, such as syllables or intonation,” Turkeltaub explains.
“These results also demonstrate the interaction between motor systems and perception. It’s really pretty amazing. Imagine you’re waving an American flag while listening to one of the presidential candidates. The speech will actually sound slightly different to you depending on whether the flag is in your left hand or your right hand.”
Ultimately, Turkeltaub hopes that understanding the basic organization of auditory systems and how they interact with motor systems will help explain why language resides in the left hemisphere of the brain, and will lead to new treatments for language disorders, like aphasia (language difficulties after stroke or brain injury) or dyslexia.
“If we can understand the basic brain organization for audition, this might ultimately lead to new treatments for people who have speech recognition problems due to stroke or other brain injury. Understanding better the specific roles of the two hemispheres in auditory processing will be a big step in that direction. If we find that people with aphasia, who typically have injuries to the left hemisphere, have difficulty recognizing speech because of problems with low-level auditory perception of rapidly changing sounds, maybe training the specific auditory processing deficits will improve their ability to recognize speech,” Turkeltaub concludes.
(Source: explore.georgetown.edu)