Showing posts with label learning. Show all posts
Showing posts with label learning. Show all posts

Monday, December 5, 2016

leanring -- Some Weather

reposted from Scientist



Some Weather

An orangutan takes shelter beneath an umbrella made from branches. That animals can use tools in such sophisticated ways can be explained with the help of a new learning model for animal behavior.
By  | December 5, 2016
EUREKALERT, JOHAN LIND
(See M. Enquist, J. Lind, and S. Ghirlanda, “The power of associative learning and the ontogeny of optimal behaviour,” Royal Society Open Science, doi:10.1098/rsos.160734, 2016.)

Thursday, March 19, 2015

Talk on Memory and Attention measured in Human Brain Cells

CVR speaker -
http://www.rutishauserlab.org/

Talk on Memory and Attention measured in Human Brain Cells 

where: BSB 163 - Behavioral Science Building Room 163 (York University Campus)
when: 4pm-5pm,
           Thursday 19th of March

Probing the Mechanisms of Learning and Memory at the Single-Neuron Level in Humans

(Ueli Rutishauser (Assist. Prof.) Neurosurgery, Neurology & Biomedical Sciences, Cedars-Sinai Medical Center)

Summary: How neuronal circuits enable complex behaviors such as learning and decision making remains poorly understood. We take advantage of rare neurosurgical procedures to record at single-cell resolution in behaving humans. I will review our experimental studies of individual neurons in the human hippocampus and amygdala during the formation and retrieval of declarative memories. These studies provide unique mechanistic insights into the relationship between neuronal activity, plasticity, memory formation, and the role of theta in coordinating large-scale neuronal dynamics. I will describe evidence for two distinct functional types of neurons in the human medial temporal lobe: visually selective (VS) and memory selective (MS) neurons. VS neurons have highly specific sensory responses that occur early and irrespective of previous experience. MS neurons, on the other hand, are not visually selective, and are highly sensitive to previous experience and the internal brain state. Dynamically, the response of these two subpopulations is orthogonal to each other. I will further describe evidence that MS and VS neurons are anatomically distinct and that their interaction is fundamental to the formation and retrieval of memories. These two functional subpopulations are a candidate for a circuit-level description of memory formation.






Books
Fried I, Rutishauser U, Cerf M, Kreiman G, eds. Single Neuron Studies of the Human Brain — Probing Cognition. MIT Press: Boston; 2014.


Saturday, October 18, 2014

Myelin’s Role in Motor Learning

reposted from - but I love the 2nd comment below about exercise and MS

Myelin’s Role in Motor Learning

The production of new myelin in the brain—a function of non-neuronal glial cells—may be necessary for motor learning, a mouse study shows.
By  | October 16, 2014
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Oligodendrocytes extend thin processes of their cell membranes to form the myelin sheaths that wrap around neuronal axons.WIKIMEDIA, LADYOFHATSChanges in myelin, the fatty sheaths that insulate neuronal axons, may play a role in motor learning, according to a study published today (October 16) in Science. Genetically engineered mice that could not produce myelin were less skilled at learning a new motor task—running on a wheel with unevenly spaced rungs—than control mice.
“The paper shows very clearly that the ability to generate new myelin is necessary for adult mice to learn a complex motor task,” said the University of Michigan’s Gabriel Corfas, author of an accompanying commentary in Science and who was not involved in the research.
Moreover, because myelin is produced by non-neuronal glial cells called oligodendrocytes, which myelinate axons by extending thin processes of their cell membranes to wrap around them, the study challenges the long-standing assumption that learning results exclusively from changes to neuronal anatomy or function. “What this paper really does in a very compelling and elegant way is show that the glial cells . . . really perform much more important tasks than had hitherto been assigned to them,” said Robin Franklin, professor at the University of Cambridge, who studies the process of remyelination and who was not involved in the work. “This paper is a very significant step in a mounting body of work that shows that in fact the glial cells are not simply cells for neurons; they have, in their own right, fundamentally important roles in how the brain works.”
“This is a very significant paradigm shift in the ways we think about how the brain changes in order to acquire information,” Corfas agreed.
Magnetic resonance imaging experiments in humans and rats have associated changes in the brain’s white matter, myelinated axons bundled together in large cables, with training in motor skills, but exactly how and why those changes were occurring was unclear. William Richardson, director of the Wolfson Institute for Biomedical Research at University College London, and his colleagues used a genetic system to selectively excise part of a gene called myelin regulatory factor (Myrf), inactivating it, in the oligodendrocyte precursor cells of laboratory mice. Myrf is not typically expressed in oligodendrocyte precursors but is necessary for the differentiation of new oligodendrocytes. “It’s not expressed until the precursors try and differentiate and express Myrf, and then if Myrf is missing, they just get stuck at that point,” said Richardson, “and we believe they die.” In other words, no Myrf means no new oligodendrocytes, and thus no new myelin. The system did not, however, affect preexisting oligodendrocytes.
Sure enough, mice lacking both copies of Myrf had fewer new oligodendrocytes and less myelin in the corpus callosum, a highly myelinated area that connects the two hemispheres of the brain and is involved in motor learning, compared with mice in which only one copy was deleted. Loss of Myrf also prevented mice from learning to run on a complex running wheel, with rungs unevenly spaced. Mice with both copies of Myrf quickly learned to use the new wheel and ran faster and farther per night than mice whose Myrf genes were inactivated.
To confirm that Myrf was impairing learning specifically, and not just motor skills in general, researchers tried introducing mice to the complex wheel before excising Myrf. In mice that had already learned to use the complex wheel, loss of Myrf had no effect on running speed, suggesting that myelin is important for learning but not recall or motor coordination.
“It’s known that the synapses between neurons strengthen when the circuits those neurons are a part of fire, and that has always been believed to be what underpins learning—this synaptic strengthening, so-called long-term potentiation,” said Richardson. “What our study shows is that although that undoubtedly does occur, there’s an additional refinement . . . which is that the active circuits presumably must get myelinated.”
Richardson added that he and his colleagues next plan to explore the roles of oligodendrocytes in other kinds of learning as well. “By finding a new mechanism involved in learning, it gives us a whole new target that in future we might be able to manipulate in order to, say, improve or accelerate learning,” said Richardson. Such information about the roles of myelination in learning could also be relevant to demyelinating diseases, such as multiple sclerosis, he added.
“I think this is an outstanding piece of work,” Franklin said. “It’s a landmark study in myelin biology and in neuroscience.”
I.A. McKenzie et al., “Motor skill learning requires active central myelination,” Science, doi:10.1126/science.1254960, 2014.
Avatar of: Kim Krieger
Posts: 2
October 17, 2014
Oligodendrocyte precursor cells are so numerous in the brain, and yet we understand so little about their role(s)...it would be interesting to explore what other functions were affected by the deletion of Myrf.
    Avatar of: Jensch
    Posts: 1
    October 17, 2014
    I've had MS for 14 years, determined by a brain biopsy.  The first few years I had relapses, then I decided to get my college math degree. I've been I school for about 6 years pretty much full time, but since I have, I haven't had one relapse.  I truly believe if you can push your mind and keep it active, along with your body it has tremendous benefit. I've never been in better shape, and I feel like I've never been healthier. I do also exercise and eat good too.

    Tuesday, June 3, 2014

    Motor Learning In Dance

    just found this posting and am reposted it here from http://www.4dancers.org/2013/01/motor-learning-in-dance/

    Motor Learning In Dance

    This month one of our guest authors is Donna Krasnow, PhD, a long-time leader and researcher in dance medicine and science. One of her areas of specialization is Motor Learning —i.e, how the body learns movement.  There are many aspects to the recent research in this field that are helpful for dancers / teachers to be aware of, so Donna’s article is a welcome addition to our growing list of topics to share with you.
    As always, if you have any comments / questions, we would love to hear from you!  – Jan Dunn, Dance Wellness Editor
    ________________________________________________________________________
    Motor Learning In Dance
    by Donna Krasnow, PhD
    When we look at how dancers move and how they learn to dance, we sometimes call this motor behavior.  One area of motor behavior is known as motor development.  This answers questions about how we change from birth to our senior years.  For example, anyone who has taught young children will know that the 3-4 years olds can gallop and hop, but most cannot skip yet.  By the time children are 6 years old, most can skip, as they have developed enough motor control to do this complex task.
    Motor control tells us how the brain can plan and direct our movement.  One example of this is what we call muscle synergies, or how groups of muscles learn to work together.  Some of these synergies are learned through our natural development, such as the easy oppositional swing of the arms to the legs in everyday walking.  Some are specific to dance, such as moving through space maintaining turnout, or learning to lift the arms overhead while keeping the shoulders down.
    What is motor learning?
    motor learning in dance
    Motor learning is the area of study that looks at how the dancer learns new movement, but not just in a single class or practice session.  When we use the term motor learning, we are referring to changes that are learned through practice and are permanent, or “remembered” on some level, even if that remembering is not something we are aware of.  Simply being able to do something new for a minute in class does not mean it has been learned, as all teachers know!
    The learning process
    What affects how dancers learn?  We know that individuals have different learning styles:
    • Some learn visually, and need to see demonstrations to learn well.
    • Others need verbal instructions or explanations to do their best.
    • Some are what we call “kinesthetic”, and need hands-on information, or touch.
    The most effective teachers use a variety of ways to present and instruct, and dancers who can learn how to broaden their learning styles will be able to work with many different teachers and choreographers.
    Demonstrating
    Most dancers, especially beginners, need to see demonstrations of new material, or material they want to improve.  With demonstrations, dancers can see how the different body parts organize, how the movement fits rhythmically with the music, how the body orients in space, and many other important aspects of the movement.  Often it is best to let the dancers see one or more demonstrations, try the combination first, and then give them additional instructions. We know from the research in motor learning that it is very easy to overload the dancer, especially the beginner, with too much information at the start of learning new material, and this will hinder rather than aid learning.
    Giving feedback
    So what about feedback after material has been seen and attempted?  First let’s look at when feedback should be given, and how often.  We can give feedback to dancers, usually called corrections, during their movement or after they have done the combination.  If feedback is being given while the dancer is moving, it is important that it enhances or adds to what they are already doing, rather than try to get them to completely change their efforts.  For example, during a series of leaps, one could say “Yes, stretch your legs even more, and lift up through the top of your head!”
    Corrections that are intended to make a shift or change should be saved for the time between attempts.  This might include a change in timing, or a change in the positioning of the arms during the movement, or a total shift in spatial direction.  It is very difficult for the dancer to make a change in approach or strategy while in motion, as it demands too much attention.  This might actually cause a deterioration in the skill.
    dance correctionsWhen it comes to the question of “how often” we should give feedback, the traditional view was “the more the merrier”.  We now know that constant feedback is not as useful as giving dancers the opportunity to have time to practice without ongoing information.  It allows what we call problem-solving time, and in the long run makes the dancer a better learner and a stronger dancer.
    What do we know about the nature of feedback?  Should it be about what the dancer is doing wrong, or should we praise what they are doing correctly?  The answer to this question is both, but for different reasons!  In order to improve, dancers need to hear what they are doing wrong (known as error detection) in order to make changes.  More advanced dancers can often figure this out themselves, but beginners need help with this. This does not mean that the teacher’s tone needs to be harsh or insulting or demeaning.  Feedback can be given is a supportive and encouraging voice.
    On the other side of things, praise and recognition of what is being done correctly is extremely important for motivation.  While it will not improve the skill level per se, it will encourage the dancer to continue practicing, and to feel confident about his or her work.  And this will, in the end, improve the dancer’s abilities.
    A word about video
    Does it help dancers see themselves on video?  There is a lot of controversy about this process.  One thing we do know is that if beginning dancers are going to look at video of their dancing, the instructor needs to be present to point out what the dancers can learn from their observations, and how to improve their next attempts.  Seeing video with no educated information is not that useful as a learning tool.
    Effective practice
    Another important subject that motor learning researchers look at is retention.  Since learning is about making new information and skills relatively permanent, how do dancers retain information?  Clearly dancers need a great deal of practice, practice, practice.  It can take hundreds if not thousands of hours to learn a body of dance skills.  However, a few boundaries should be observed.
    First, constant practice without feedback can be detrimental.  If the dancer is practicing something incorrectly, then this error will become permanently imbedded in the skill!  We hope to guide the dancer towards more effective execution with each practice.
    Second, practice should never be pushed to the point of fatigue and injury.  Rest is an important part of the big picture, and we know that even during sleep, the brain continues to process new information and learn.
    Third, practice needs variety.  Try doing the skill at different speeds, with changes in the space, with different arm or leg gestures, and even with different emotional intention.  Variety challenges the motor system.  Although it may seem that practicing a skill the same way over and over leads to the best learning, this is a myth.  Varying the skill may at first look awkward and confused, but in the long run, it results in better learning.  And let’s not forget that variety is a great way to avoid boredom and keep the dancer attentive.  Without attention, there is no learning.
    Learning on right or left?
    learning danceAnother issue that has come up in the study of dance and motor learning is the question of laterality, or on what side should we be learning new material, right or left?  Recent articles in dance have suggested that we should be learning on the left (non-dominant) side first, at least some of the time.  Interestingly, when we look at the research on this in other fields, what we know is this: First, there is learning transfer, so if you learn something on the right, some of that information is automatically learned on the left, and vice versa.  Second, that transfer is stronger when you learn on the dominant (right for most) side first.  This seems to contradict what the dance writers are saying.
    I would suggest that the problem is not that we learn on the right side first, but that due to class procedure, this gives the dancers far more practice on the first side.  Often the teacher will demonstrate on the first side (while many dancers are following along), then give verbal information (while dancers practice), then mark it on the first side, then finally do it full out on the first side.  Then the dancers might do a quick mark on the second side, and do the combination.  This process is biased towards much more repetition on the first side.  Teachers need to ensure that there are extra attempts on the second side, to even out the practice.
    Using mirrors
    One other learning tool that is fairly universal in dance is the use of mirrors.  Again, this is an area of controversy.  What do we actually know?  There is some research that suggests that learning is faster using mirrors, but less is retained or remembered the next day, or in future days.  More importantly, learning with the mirror may actually be detrimental to kinesthetic learning, that is, the dancer knowing from “feel” how to do something.  In a study with athletes who worked with mirrors, they were practicing how to keep the knee aligned with the foot to prevent injury (sound familiar?).  When they turned away from the mirror, their errors (knee going off the correct line) increased by 50%.  Ouch.
    A final word
    The last controversial topic I will mention is how we use language to give instruction.  As tempting as it is, bringing dancers’ attention to a specific muscle while they are dancing is generally not a useful approach.  It is better to describe movement outcomes or goals, and let the brain select the muscles.  This can be done in a variety of ways, including describing movement shaping (draw a large arch on the floor with your foot as your body lengthens vertically), or using metaphor (lift up your chest and eyes as you open your arms as if you want the sun to warm your upper body), or anatomical imagery (imagine your shoulder blades sliding down your back like they are melting as your arms are going up to 5th position).
    Teachers are creative artists who can draw on their years of expertise and imagination to create a class that draws on all of the current motor learning ideas while maintaining the beautiful traditions of our art form.
    Donna Krasnow
    Donna Krasnow, PhD
    BIO: Donna Krasnow, PhD, is a Full Professor in the Department of Dance at York University in Toronto, and a lecturer at California State University, Northridge, and California Institute of the Arts. For the past thirty years she has worked professionally as a choreographer, performer, dance educator, and researcher. She was founding Artistic Director for Möbius Dance Company in San Francisco, and has performed and taught extensively in the United States, Canada, Australia, and Japan. Donna has performed with Footloose Dance Company (San Francisco), Daniel Lewis Repertory Dance Company (New York), Northern Lights Dance Company (Toronto) and as performing as a guest artist with Bill T. Jones / Arnie Zane Dance Company in its 1990 Toronto season. She is noted for her teaching of the José Limón technique and has taught for the José Limón Dance Institute in New York. Donna was head of the modern division at the Canadian Children’s Dance Theatre in Toronto from 1988-2007, where she has developed a curriculum for young dancers (10-18 years old) integrating Limón technique, improvisation and composition.
    Donna specializes in dance science research, concentrating on dance kinesiology, injury prevention and care, conditioning for dancers, and motor learning and motor control, with a special emphasis on the young dancer. She was the Conference Director for the International Association for Dance Medicine and Science from 2004-2008, and served on the IADMS Board of Directors from 1996-2008. She has also served on the Board of Directors of the Performing Arts Medicine Association, and was a founding member of Healthy Dancer Canada.  Donna conducts workshops for professional dance teachers in alignment and healthy practices for dancers, including the Teachers Day Seminars at York University, Arts Umbrella in Vancouver, and a nine-time resident guest artist at the Victorian College of the Arts, University of Melbourne, Australia. She has been a keynote speaker for professional dance associations such as Cecchetti Australia, and an invited speaker for A Day for Teachers, sponsored by IADMS, on several occasions. She regularly consults on curriculum development for various colleges and universities. In addition to being a GYROTONIC trainer since 2005, Donna has created a specialized body conditioning system for dancers called C-I Training™ (conditioning with imagery). She has produced a DVD series of this work, and in 2010 published the book Conditioning with Imagery for Dancers with co-author Jordana Deveau. Information about the dvds and the book can be found at www.citraining.com. ; She has also published extensively in the Journal of Dance Medicine and Science, Medical Problems of Performing Artists, and Journal of Dance Education, as well as invited author for three resource papers for IADMS, in collaboration with Dr. Virginia Wilmerding.  Donna completed her PhD in 2012 doing biomechanics research on dancers through the University of Wolverhampton in the UK, and is currently working on a new book on Motor Learning for Dancers with Dr. Virginia Wilmerding for Human Kinetics.

    Wednesday, April 23, 2014

    Structural Plasticity within the Barrel Cortex during Initial Phases of Whisker-Dependent Learning

    reposted from

    Structural Plasticity within the Barrel Cortex during Initial Phases of Whisker-Dependent Learning

    1. Karel Svoboda1
    1. Author contributions: S.J.K., D.H.O., K.F., and K.S. designed research; S.J.K. performed research; S.J.K. analyzed data; S.J.K., D.H.O., K.F., and K.S. wrote the paper.
    1. The Journal of Neuroscience,34(17): 6078-6083; doi: 10.1523/JNEUROSCI.4919-12.2014

    Abstract

    We report learning-related structural plasticity in layer 1 branches of pyramidal neurons in the barrel cortex, a known site of sensorimotor integration. In mice learning an active, whisker-dependent object localization task, layer 2/3 neurons showed enhanced spine growth during initial skill acquisition that both preceded and predicted expert performance. Preexisting spines were stabilized and new persistent spines were formed. These findings suggest rapid changes in connectivity between motor centers and sensory cortex guide subsequent sensorimotor learning.