Posts tagged learning
Articles and news from the latest research reports.
Babies can learn their first lullabies in the womb
An infant can recognise a lullaby heard in the womb for several months after birth, potentially supporting later speech development. This is indicated in a new study at the University of Helsinki.
The study focused on 24 women during the final trimester of their pregnancies. Half of the women played the melody of Twinkle Twinkle Little Star to their fetuses five days a week for the final stages of their pregnancies. The brains of the babies who heard the melody in utero reacted more strongly to the familiar melody both immediately and four months after birth when compared with the control group. These results show that fetuses can recognise and remember sounds from the outside world.
This is significant for the early rehabilitation, since rehabilitation aims at long-term changes in the brain.
“Even though our earlier research indicated that fetuses could learn minor details of speech, we did not know how long they could retain the information. These results show that babies are capable of learning at a very young age, and that the effects of the learning remain apparent in the brain for a long time,” expounds Eino Partanen, who is currently finishing his dissertation at the Cognitive Brain Research Unit.
“This is the first study to track how long fetal memories remain in the brain. The results are significant, as studying the responses in the brain let us focus on the foundations of fetal memory. The early mechanisms of memory are currently unknown,” points out Dr Minna Huotilainen, principal investigator.
The researchers believe that song and speech are most beneficial for the fetus in terms of speech development. According to the current understanding, the processing of singing and speech in the babies brains are partly based on shared mechanisms, and so hearing a song can support a baby’s speech development. However, little is known about the possible detrimental effects that noise in the workplace can cause to a fetus during the final trimester. An extensive research project on this topic is underway at the Finnish Institute of Occupational Health.
Baby brains are tuned to the specific actions of others
Imitation may be the sincerest form of flattery for adults, but for babies it’s their foremost tool for learning. As renowned people-watchers, babies often observe others demonstrate how to do things and then copy those body movements. It’s how little ones know, usually without explicit instructions, to hold a toy phone to the ear or guide a spoon to the mouth.
Now researchers from the University of Washington and Temple University have found the first evidence revealing a key aspect of the brain processing that occurs in babies to allow this learning by observation.
The findings, published online Oct. 30 by PLOS ONE, are the first to show that babies’ brains showed specific activation patterns when an adult performed a task with different parts of her body. When 14-month-old babies simply watched an adult use her hand to touch a toy, the hand area of the baby’s brain lit up. When another group of infants watched an adult touch the toy using only her foot, the foot area of the baby’s brain showed more activity.
"Babies are exquisitely careful people-watchers, and they’re primed to learn from others," said Andrew Meltzoff, co-author and co-director of the UW Institute for Learning & Brain Sciences. "And now we see that when babies watch someone else, it activates their own brains. This study is a first step in understanding the neuroscience of how babies learn through imitation."
The study took advantage of how the brain is organized. The sensory and motor area of the cortex, the outer portion of the brain known for its creased appearance, is arranged by body part with each area of the body represented in identifiable neural real estate. Prick your finger, stick out your tongue, or kick a ball and distinct areas of the brain light up according to a somatotopic map.
Other studies show that adults show this somatotopic brain activation while watching someone else use different body parts, suggesting that adults understand the actions of others in relation to their own bodies. The researchers wondered whether the same would be true in babies.
The 70 infants in the study wore electroencephalogram, or EEG, caps with embedded sensors that detected brain activity in the regions of the cortex that respond to movement or touch of the feet and hands. Sitting on a parent’s lap, each baby watched as an experimenter touched a toy placed on a low table between the baby and the experimenter.
The toy had a clear plastic dome and was mounted on a sturdy base. When the experimenter pressed the dome with her hand or foot, music played and confetti in the dome spun. The experimenter repeated the action – taking breaks after every four presses – until the baby lost interest.
"Our findings show that when babies see others produce actions with a particular body part, their brains are activated in a corresponding way," said Joni Saby, lead author and a psychology graduate student at Temple University in Philadelphia. "This mapping may facilitate imitation and could play a role in the baby’s ability to then produce the same actions themselves."
One of the basics for babies to learn is how to copy what they see adults do. In other words, they must first know that it is indeed their hand and not their foot, mouth or other body part that is needed.
The new study shows that babies’ brains are organized in a somatotopic way that helps crack the interpersonal code. The connection between doing and seeing actions maps hand to hand, foot to foot, all before they can name those body parts through language.
"The reason this is exciting is that it gives insight into a crucial aspect of imitation," said co-author Peter Marshall, an associate psychology professor at Temple University. "To imitate the action of another person, babies first need to register what body part the other person used. Our findings suggest that babies do this in a particular way by mapping the actions of the other person onto their own body."
Meltzoff added, “The neural system of babies directly connects them to other people, which jump-starts imitation and social-emotional connectedness and bonding. Babies look at you and see themselves.”
A Trace of Memory: Researchers Watch Neurons in the Brain During Learning and Memory Recall
A team of neurobiologists led by Simon Rumpel at the Research Institute of Molecular Pathology (IMP) in Vienna succeeded in tracking single neurons in the brain of mice over extended periods of time. Advanced imaging techniques allowed them to establish the processes during memory formation and recall. The results of their observations are published this week in PNAS Early Edition.
Most of our behavior – and thus our personality – is shaped by previous experience. To store the memory of these experiences and to be able to retrieve the information at will is therefore considered one of the most basic and important functions of the brain. The current model in neuroscience poses that memory is stored as long-lasting anatomical changes in synapses, the specialized structures by which nerve cells connect and signal to each other.
At the Research Institute of Molecular Pathology (IMP) in Vienna, Simon Rumpel and Kaja Moczulska used mice to study the effects of learning and memorizing on the architecture of synapses. They employed an advanced microscopic technique called in vivo two-photon imaging that allows the analysis of structures as small as a thousandth of a millimetre in the living brain.
Using this technology, the neurobiologists tracked individual neurons over the course of several weeks and analysed them repeatedly. They focussed their attention on dendritic spines that decorate the neuronal processes and correspond to excitatory synapses. The analyses were combined with behavioral experiments in which the animals underwent classic auditory conditioning. The results showed that the learning experience triggered the formation of new synaptic connections in the auditory cortex. Several of these new structures persisted over time, suggesting a long-lasting trace of memory and confirming an important prediction of the current model.
Apart from the changes during memory formation, the IMP-scientists were interested in the act of remembering. Earlier studies had shown that memory recall is associated with molecular processes similar to the initial formation of memory. These similarities have been suggested to reflect remodelling of memory traces during recall.
To test this hypothesis, previously trained mice were exposed to the auditory cue a week after conditioning while tracking dendritic spines in the auditory cortex. The results showed that although some molecular processes indeed resembled those during memory formation, the anatomical structure of the synapses did not change. These findings suggest that memory retrieval does not lead to a modification of the memory trace per se. Instead, the molecular processes triggered by memory formation and recall could reflect the stabilization of previously altered or recently retrieved synaptic connections.
The primary goal of elucidating the processes during memory formation and recall is to increase our basic knowledge. Insights gained from these studies might however help us to understand diseases of the nervous system that affect memory. They may also, in the future, provide the basis for treatments that offer relief to traumatized patients.
Brainpower applied to understanding of neural stem cells
How do humans and other mammals get so brainy? USC researcher Wange Lu and his colleagues shed new light on this question in a paper published in the journal Cell Reports on Oct. 24.
The researchers donned their thinking caps to explain how neural stem and progenitor cells differentiate into neurons and related cells called glia. Neurons transmit information through electrical and chemical signals; glia surround, support and protect neurons in the brain and throughout the nervous system. Glia do everything from holding neurons in place to supplying them with nutrients and oxygen to protect them from pathogens.
By studying the embryo neural stem cells of mice in a petri dish, Lu and his colleagues discovered that a protein called SMEK1 promotes the differentiation of neural stem and progenitor cells. At the same time, SMEK1 keeps these cells in check by suppressing their uncontrolled proliferation.
The researchers also determined that SMEK1 doesn’t act alone: It works in concert with Protein Phosphatase 4 to suppress the activity of PAR3, a third protein that discourages neurogenesis — the birth of new neurons. With PAR3 out of the picture, neural stem cells and progenitors are free to differentiate into new neurons and glia.
“These studies reveal the mechanisms of how the brain keeps the balance of stem cells and neurons when the brain is formed,” said Wange Lu, associate professor of biochemistry and molecular biology at the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC. “If this process goes wrong, it leads to cancer or mental retardation or other neurological diseases.”
Neural stem and progenitor cells offer tremendous promise as a future treatment for neurodegenerative disorders, and understanding their differentiation is the first step toward harnessing the cells’ therapeutic potential. This could offer new hope for patients with Alzheimer’s, Parkinson’s and many other currently incurable diseases.
Most songbirds learn their songs from an adult model, mostly from the father. However, there are relatively large differences in the accuracy how these songs are copied. Researchers from the Max Planck Institute for Ornithology in Seewiesen now found in juvenile zebra finches a possible mechanism that is responsible for the differences in the intensity of song learning. They provided the nerve growth factor “BDNF” to the song control system in the brain. With this treatment the learning ability in juvenile males could be enhanced in such a way that they were able to copy the songs of the father as good as it had been observed in the best learners in a zebra finch nest.
The improvement of cognitive abilities plays an important role in the therapy of neurological and psychiatric diseases. In this context research focusses more and more on the protein BDNF (Brain Derived Neurotrophic Factor). BDNF is mainly responsible for the preservation, growth and differentiation of nerve cells. Moreover, from experiments in mice it is known that BDNF enhances the ability to solve complex cognitive tasks.
In a learning experiment with zebra finches, researchers from the Max Planck Institute for Ornithology in Seewiesen in collaboration with scientists from the Free University of Amsterdam could now show for the first time in songbirds that BDNF acts as cognitive enhancer. They investigated zebra finch brother pairs that grew up with their genetic parents. In this setup juvenile birds will readily learn the songs from their fathers. However there are differences in the intensity of song learning among siblings of the same age. The worst learners have only a similarity of 20% with their fathers’ songs, whereas the best learners copy almost the entire songs of their fathers.
By now knowing the normal distribution of the learned songs within a zebra finch nest, as a next step the researchers were able to investigate the impact of BDNF on song learning. In one of the two brothers they enhanced the expression of BDNF in the song control system in the brain while the other brother did not get such a treatment. By analysing the songs the researchers found that those sons that received more BDNF had a higher similarity with the song of their fathers compared to normally reared juveniles. Remarkably, the learning efficiency in the BDNF-treated birds was as high as it has been previously observed in the best learners within the nest. This was due to an earlier onset of syllable copying in BDNF-treated birds and these birds also copied more and sang fewer improvised syllables. Therefore it is likely that the presence of BDNF in the song control system could correct possible inaccuracies in the song learning process, state the scientists around Manfred Gahr, who is the senior author of the study.
Learning New Skills Keeps an Aging Mind Sharp
Older adults are often encouraged to stay active and engaged to keep their minds sharp, that they have to “use it or lose it.” But new research indicates that only certain activities — learning a mentally demanding skill like photography, for instance — are likely to improve cognitive functioning.
These findings, forthcoming in Psychological Science, a journal of the Association for Psychological Science, reveal that less demanding activities, such as listening to classical music or completing word puzzles, probably won’t bring noticeable benefits to an aging mind.
“It seems it is not enough just to get out and do something—it is important to get out and do something that is unfamiliar and mentally challenging, and that provides broad stimulation mentally and socially,” says psychological scientist and lead researcher Denise Park of the University of Texas at Dallas. “When you are inside your comfort zone you may be outside of the enhancement zone.”
The new findings provide much-needed insight into the components of everyday activities that contribute to cognitive vitality as we age.
“We need, as a society, to learn how to maintain a healthy mind, just like we know how to maintain vascular health with diet and exercise,” says Park. “We know so little right now.”
For their study, Park and colleagues randomly assigned 221 adults, ages 60 to 90, to engage in a particular type of activity for 15 hours a week over the course of three months.
Some participants were assigned to learn a new skill — digital photography, quilting, or both — which required active engagement and tapped working memory, long-term memory and other high-level cognitive processes.
Other participants were instructed to engage in more familiar activities at home, such as listening to classical music and completing word puzzles. And, to account for the possible influence of social contact, some participants were assigned to a social group that included social interactions, field trips, and entertainment.
At the end of three months, Park and colleagues found that the adults who were productively engaged in learning new skills showed improvements in memory compared to those who engaged in social activities or non-demanding mental activities at home.
“The findings suggest that engagement alone is not enough,” says Park. “The three learning groups were pushed very hard to keep learning more and mastering more tasks and skills. Only the groups that were confronted with continuous and prolonged mental challenge improved.”
The study is particularly noteworthy given that the researchers were able to systematically intervene in people’s lives, putting them in new environments and providing them with skills and relationships:
“Our participants essentially agreed to be assigned randomly to different lifestyles for three months so that we could compare how different social and learning environments affected the mind,” says Park. “People built relationships and learned new skills — we hope these are gifts that keep on giving, and continue to be a source of engagement and stimulation even after they finished the study.”
Park and colleagues are planning on following up with the participants one year and five years down the road to see if the effects remain over the long term. They believe that the research has the potential to be profoundly important and relevant, especially as the number of seniors continues to rise:
“This is speculation, but what if challenging mental activity slows the rate at which the brain ages?” asks Park. “Every year that you save could be an added year of high quality life and independence.”
Learning dialects shapes brain areas that process spoken language
Using advanced imaging to visualize brain areas used for understanding language in native Japanese speakers, a new study from the RIKEN Brain Science Institute finds that the pitch-accent in words pronounced in standard Japanese activates different brain hemispheres depending on whether the listener speaks standard Japanese or one of the regional dialects.
In the study published in the journal Brain and Language, Drs. Yutaka Sato, Reiko Mazuka and their colleagues examined if speakers of a non-standard dialect used the same brain areas while listening to spoken words as native speakers of the standard dialect or as someone who acquired a second language later in life.
When we hear language our brain dissects the sounds to extract meaning. However, two people who speak the same language may have trouble understanding each other due to regional accents, such as Australian and American English. In some languages, such as Japanese, these regional differences are more pronounced than an accent and are called dialects.
Unlike different languages that may have major differences in grammar and vocabulary, the dialects of a language usually differ at the level of sounds and pronunciation. In Japan, in addition to the standard Japanese dialect, which uses a pitch-accent to distinguish identical words with different meanings, there are other regional dialects that do not.
Similar to the way that a stress in an English word can change its meaning, such as “pro’duce” and “produ’ce”, identical words in the standard Japanese language have different meanings depending on the pitch-accent. The syllables of a word can have either a high or a low pitch and the combination of pitch-accents for a particular word imparts it with different meanings.
The experimental task was designed to test the participants’ responses when they distinguish three types of word pairs: (1) words such as /ame’/ (candy) versus /kame/ (jar) that differ in one sound, (2) words such as /ame’/ (candy) versus /a’me/ (rain) that differ in their pitch accent, and (3) words such as ‘ame’ (candy in declarative intonation) and /ame?/ (candy in a question intonation).
RIKEN neuroscientists used Near Infrared Spectroscopy (NIRS) to examine whether the two brain hemispheres are activated differently in response to pitch changes embedded in a pair of words in standard and accent-less dialect speakers. This non-invasive way to visualize brain activity is based on the fact that when a brain area is active, blood supply increases locally in that area and this increase can be detected with an infrared laser.
It is known that pitch changes activate both hemispheres, whereas word meaning is preferentially associated with the left-hemisphere. When the participants heard the word pair that differed in pitch-accent, /ame’/ (candy) vs /a’me/ (rain), the left hemisphere was predominantly activated in standard dialect speakers, whereas in accent-less dialect speakers did not show the left-dominant activation. Thus, standard Japanese speakers use the pitch-accent to understand the word meaning. However, accent-less dialect speakers process pitch changes similar to individuals who learn a second language later in life.
The results are surprising because both groups are native Japanese speakers who are familiar with the standard dialect. “Our study reveals that an individual’s language experience at a young age can shape the way languages are processed in the brain,” comments Dr. Sato. “Sufficient exposure to a language at a young age may change the processing of a second language so that it is the same as that of the native language.”
Two-legged Robots Learn to Walk like a Human
Teaching two-legged robots a stable, robust “human” way of walking – this is the goal of the international research project “KoroiBot” with scientists from seven institutions from Germany, France, Israel, Italy and the Netherlands. The experts from the areas of robotics, mathematics and cognitive sciences want to study human locomotion as exactly as possible and transfer this onto technical equipment with the assistance of new mathematical processes and algorithms. The European Union is financing the three-year research project that started in October 2013 with approx. EUR 4.16 million. The scientific coordinator is Prof. Dr. Katja Mombaur from Heidelberg University.
Whether as rescuers in disaster areas, household helps or as “colleagues” in modern work environments: there are numerous possible areas of deployment for humanoid robots in the future. “One of the major challenges on the way is to enable robots to move on two legs in different situations, without an accident – in spite of unknown terrain and also with possible disturbances,” explains Prof. Mombaur, who heads the working group “Optimisation in Robotics and Biomechanics” at Heidelberg University’s Interdisciplinary Center for Scientific Computing (IWR).
In the KoroiBot project the researchers will study the way humans walk e.g. on stairs and slopes, on soft and slippery ground or over beams and seesaws, and create mathematical models. Besides developing new optimisation and learning processes for walking on two legs, they aim to implement this in practice with existing robots. In addition, the research results are to flow into planning new design principles for the next generation of robots.
Besides Prof. Mombaur’s group, the working group “Simulation and Optimisation” is also involved in the project at the IWR. The Heidelberg scientists will investigate the way movement of humans and robots can be turned into mathematical models. Furthermore, the teams want to create optimised walking movements for different demands and develop new model-based control algorithms. Just under EUR 900,000 of the European Union funding is being channelled to Heidelberg.
Partners in the international consortium are, besides Heidelberg University, leading institutions in the field of robotics. These include the Karlsruhe Institute of Technology (KIT), the Centre National de la Recherche Scientifique (CNRS) with three laboratories, the Istituto Italiano di Tecnologia (IIT) and the Delft University of Technology in the Netherlands. Experts from the University of Tübingen and the Weizmann Institute of Science in Israel will contribute from the angle of cognitive sciences.
Besides the targeted use of robotics, the scientists expect possible applications in medicine, e.g. for controlling intelligent artificial limbs. They see further areas of application in designing and regulating exoskeletons as well as in computer animation and in game design.
(Source: uni-heidelberg.de)
Video could transform how schools serve teens with autism
Video-based teaching helps teens with autism learn important social skills, and the method eventually could be used widely by schools with limited resources, a Michigan State University researcher says.
The diagnosis rate for Autism Spectrum Disorder for 14- to 17-year-olds has more than doubled in the past five years, according to the Centers for Disease Control and Prevention. Yet previous research has found very few strategies for helping adolescents with autism develop skills needed to be successful, especially in group settings.
“Teaching social skills to adolescents with ASD has to be effective and practical,” said Joshua Plavnick, assistant professor of special education at MSU. “Using video-based group instruction regularly could promote far-reaching gains for students with ASD across many social behaviors.”
Plavnick developed group video teaching techniques with colleagues while a postdoctoral fellow at the University of North Carolina’s Frank Porter Graham Child Development Institute. Their findings are published in the research journal Exceptional Children.
Previous studies have shown many people with autism are more likely to pay attention when an innovative technology delivers information. Before Plavnick’s work, however, there were no investigations of video modeling as an option for teaching social skills to more than one adolescent with ASD at the same time.
The team recruited 13- to 17-year-old students with ASD and used laptops or iPads to offer group video instruction on social behaviors, such as inviting a peer to join an activity. One facilitator showed four students video footage of people helping one another clean up a mess, for example, and then gave them opportunities to practice the same skills in the classroom.
According to the researchers, the students demonstrated a rapid increase in the level of complex social behaviors each time video-based group instruction was used. Students sustained those social behaviors at high levels, even when the videos were used less often.
The students’ parents also completed anonymous surveys and indicated high levels of satisfaction. One reported their child started asking family members to play games together, a skill the teen had never before displayed at home.
Most schools do not have appropriate staff resources to provide one-on-one help for students with autism. The video can be used with a small group all at once and has been shown to be effective.
“Video-based group instruction is important, given the often limited resources in schools that also face increasing numbers of students being diagnosed with ASD,” said Plavnick, who also has begun implementing the strategy as part of a daily high school-based program.
(Source: msutoday.msu.edu)
To live and learn: making memories has to be a speedy business
The brain is plastic - adapting to the hundreds of experiences in our daily lives by reorganizing pathways and making new connections between nerve cells. This plasticity requires that memories of new information and experiences are formed fast. So fast that the body has a special mechanism, unique to nerve cells, that enables memories to be made rapidly. In a new study from The Montreal Neurological Institute and Hospital, The Neuro, McGill University with colleagues at the Université de Montréal, researchers have discovered that nerve cells have a special ‘pre-assembly’ technique to expedite the manufacture of proteins at nerve cell connections (synapses), enabling the brain to rapidly form memories and be plastic.
Making a memory requires the production of proteins at synapses. These proteins then change the strength of the connection or pathway. In nerve cells the production process for memory proteins is already pre-assembled at the synapse but stalled just before completion, awaiting the proper signals to finish, thereby speeding up the entire process. When it comes time to making the memory, the process is switched on and the protein is made in a flash. The mechanism is analogous to a pre-fab home, or pre-made pancake batter that is assembled in advance and then quickly completed in the correct location at the correct time.
“It’s not only important to make proteins in the right place but, it’s also important not to make the protein when it’s the wrong time,” says Dr. Wayne Sossin, neuroscientist at The Neuro and senior investigator on the paper. “This is especially important with nerve cells in the brain, as you only want the brain to make precise connections. If this process is indiscriminate, it leads to neurological disease. This mechanism to control memory protein synthesis solves two problems: 1) how to make proteins only at the right time and 2) how to make proteins as quickly as possible in order to tightly associate the synaptic change with the experience/memory.
Making proteins from genetic material involves two major steps [a Nobel prize was awarded for the identification of the cell’s protein-making process]. In the first step, called transcription, the information in DNA that is stored and protected within the centre of the cell is copied to a messenger RNA (mRNA) – this copy is then moved to where it is needed in the cell. In the second step, called translation, the mRNA is used as a template of genetic information and ‘read’ by little machines called ribosomes, which decode the mRNA sequence and stitch together the correct amino acids to form the protein.
Dr. Sossin’s group at The Neuro has discovered that the mRNA travels to the synapse already attached to the ribosome, with the protein production process stopped just before completion of the product (at the elongation/termination step of translation, where amino acids are being assembled into protein). The ‘pre-assembly’ process then waits for synaptic signals before re-activating to produce a lot of proteins quickly in order to form a memory. “Our results reveal a new mechanism underlying translation-dependent synaptic plasticity, which is dysregulated in neurodevelopmental and psychiatric pathologies”, added Dr. Sossin. “Understanding the pathways involved may provide new therapeutic targets for neurodevelopmental disorders. “
(Source: mcgill.ca)