1. Study suggests engaging children in math at home equals a boost in more than just math skills

    November 23, 2017 by Ashley

    From the Purdue University press release:

    Preschool children who engage in math activities at home with their parents not only improve their math skills, but also their general vocabulary, according to research from Purdue University.

    “Exposure to basic numbers and math concepts at home were predictive, even more so than storybook reading or other literacy-rich interactions, of improving preschool children’s general vocabulary,” said Amy Napoli, a doctoral student in the Department of Human Development and Family Studies who led the study. “And one of the reasons we think this could be is the dialogue that happens when parents are teaching their children about math and asking questions about values and comparisons, which helps these young children improve their oral language skills.”

    The findings are published online in the Journal of Experimental Child Psychology.

    “It’s never too early to talk about numbers and quantities. One of the first words young children learn is ‘more,'” said David Purpura, an assistant professor in the Department of Human Development and Family Studies, and senior author of the study.

    There are a number of ways parents can encourage math learning at home, such as talking about counting, connecting numbers to quantities and comparing values — more and less. It also helps to focus on counting as purposeful, such as “there are three cookies for a snack” rather than “there are cookies for a snack.”

    “This focus on math typically isn’t happening at home, but this shows that when parents do include math concepts it can make a difference,” said Napoli, who is working on tools to help parents improve math-related instruction at home. “When working with families, there is a math-related anxiety aspect and that is probably why more parents focus on literacy than on math. But, if you can count, then you can teach something to your child.”

    This study evaluated 116 preschool children, ages 3-5. The researchers assessed the children’s math and language skills in the fall and spring of the preschool year and examined how what their parents reported about math and literacy activities at home predicted children’s improvement over time. Napoli and Purpura do caution that these findings are only correlational and the future experimental work is needed to evaluate the causal nature of these findings. This research is ongoing work supported by Purdue’s Department of Human Development and Family Studies.


  2. Study suggests dual-language learners outperform monolingual students once they gain English proficiency

    November 16, 2017 by Ashley

    From the Iowa State University press release:

    Not all dual-language learners are at risk academically, but as a group, these students are often labeled as such, despite differences in their English skills.

    A new Iowa State University study examined how variation in dual language status among Head Start students related to development in cognitive and academic areas. The research team led by Ji-Young Choi, an assistant professor of Human Development and Family Studies, found dual-language learners (DLLs) had significant growth, eventually outperforming students who only spoke English, once DLLs gained basic English proficiency. The results are published in the journal Early Childhood Research Quarterly.

    Choi, Christine Lippard, an assistant professor of human development and family studies at Iowa State; and Shinyoung Jeon, a postdoctoral research fellow at the University of Oklahoma-Tulsa, analyzed data measuring inhibitory control (the ability to pay attention and control natural, but unnecessary thoughts or behaviors) and math achievement for low-income students in Head Start through kindergarten. The data, collected through the Head Start Family and Child Experiences Survey (FACES) 2009, included 825 children — whose home language was English or Spanish — at 59 Head Start programs across the country.

    Instead of treating DLLs as a homogenous group, researchers created two categories — Spanish-English bilinguals, who can function in both languages; and DLLs with limited English skills — based on ability entering Head Start. They identified stark differences between the DLL groups and English-only students over the course of the study. Entering Head Start, bilingual students had higher inhibitory control, but lower math scores, than English-only students did. DLLs with limited English skills lagged behind both groups. However, over the course of 18 months, bilingual students outperformed English-only students with higher scores in math and inhibitory control, despite having lower baseline scores for math at the beginning of the study.

    DLLs with limited English skills — students considered at risk when they entered Head Start — also made significant progress, the study found. These students outpaced bilingual and English-only students in the rate of gains for inhibitory control skills. While their scores had not caught up with the other two groups by the midpoint of kindergarten (the final point of analysis for the study), Choi expects with more time DLLs with limited English skills would eventually match or even outperform English-only peers as they learn more English and become bilingual.

    “Recognizing that dual-language learners can do better than we expected has huge implications. When these students do not have age-appropriate English skills they are more at risk, but once they achieve those skills they actually excel,” Choi said. “This study also confirms that there is a cognitive benefit for bilingual students.”

    Importance of inhibitory control

    The researchers say that bilingual children’s faster growth rate in inhibitory control over time helped explain the significant difference in kindergarten math skills between bilingual children and English-only students. Based on the FACES data, they could not provide a definitive explanation for the faster growth rate in inhibitory control. However, Choi says the research results lend support to the theory that bilingual students develop stronger inhibitory control skills because of their daily practice toggling between languages to fit the conversation, and inhibiting one language while speaking another.

    Inhibitory control encompasses everything from a child’s ability to suppress the impulse to grab a toy away from a friend to inhibiting the impulse to pronounce a “t” sound at the beginning of the, Lippard said. It is an important foundational skill for academic growth as well as behavior.

    Supporting students’ home language

    Recognizing skill-level differences is important given that DLLs are in more than 70 percent of Head Start classrooms. Lippard says all early childhood educators need to understand the developmental strengths of DLLs, and recognize there is no one-size-fits-all approach for teaching these students. The study makes the case for instructional support to help DLLs become proficient in English while learning or maintaining their home language. Lippard says one way to achieve that is by giving students the opportunity to engage with linguistically diverse teachers.

    “Preschool programs are so full of academic expectations that adding a Spanish lesson time may not be helpful or developmentally appropriate,” Lippard said. “Learning Spanish by interacting with a native Spanish speaker and experiencing typical preschool activities like singing songs or reading stories in Spanish holds potential benefits for all of the children in the classroom.”

    Choi would like to see instructional support for DLLs throughout their formal education. DLLs use their home language less and less as they are exposed to English in school and risk losing their home language, Choi said. While it is important for students to be proficient in English, she says DLLs would lose the potential bilingual benefits without support for their home language.


  3. How to detect the risk of dyslexia before learning to read

    November 9, 2017 by Ashley

    From the FECYT – Spanish Foundation for Science and Technology press release:

    Almost 10% of the world population suffers dyslexia. Establishing an early diagnosis would allow the development of training programs to palliate this disorder. We now may be nearer to reaching this goal thanks to a study carried out by the Basque Centre on Cognition, Brain and Language (BCBL), associating auditory processing in children to their reading skills. The results offer a new approach for detecting the risk before the children learn to read.

    Difficulty recognising words, decoding and writing problems, limitation of reading comprehension … These are the main consequences of dyslexia, a cognitive disorder of neurological origin in which a late diagnosis is the main handicap.

    A study led by investigators of the Basque Centre on Cognition, Brain and Language (BCBL) has demonstrated a relationship between the capacity of children to learn how to read and their hearing ability.

    This breakthrough, published in Frontiers in Psychology, casts light upon the detection of the disorder and could help establish the risk of dyslexia from an early stage, as well as develop training programmes to palliate reading limitations on a preemptive basis.

    “The capacity of children to listen and process language is a decisive factor in learning to read,” explains Paula Ríos-López, the supervisor of the study and a research member of the BCBL. At present, we must wait for children to reach 9 years of age in order to diagnose dyslexia.

    However, the results of the San Sebastián centre imply that measurement of hearing capacity in children from a very early age may allow us to identify those individuals that might have reading problems and therefore be more susceptible to dyslexia.

    Furthermore, different training activities could be implemented before 9 years of age, based on prosody (accents, tone and intonation) and language rhythms, together with programmes designed to palliate reading difficulties.

    The aim is to improve reading skills and avoid future disorders. “For example, we could make an activity as simple as playing a drum improve the rhythmic skills of the child with the purpose of gradually improving language perception and avoiding future disorders,” underscores Ríos-López.

    The importance of rhythm

    The study has been carried out in 40 children in the second and fifth primary school grades. In order to demonstrate the relationship between the ability to learn how to read and hearing capacity, the subjects were exposed to a pseudo-word (an invented word without meaning), which the children were required to repeat verbally when asked about it.

    The experiment showed that this word was better understood when preceded by phrases produced only with prosodic information, i.e., in which the information only consisted of rhythms and intonations, with no phonemes of any kind.

    As explained by the expert, those children that yielded poorer scores in the reading skill test were those that received most help from the phrase with prosodic information to successfully understand and repeat the pseudo-word.

    In this sense, children that do not optimally process low frequency sounds (tones, accents and intonations of speech) have greater difficulty correctly decoding phonemes and words — and this in turn is directly correlated to reading capacity and its possible disorders.

    “Rhythm offers the brain the key to focalising auditory attention in moments when information relevant to speech perception appears,” explains Ríos-López. “When the brain predicts the appearance of such information, an excitable state is produced, with the recruitment of neurons destined to adapt to it,” she concludes.


  4. Study examines how adult brain circuits regulate new neuron production

    by Ashley

    From the University of North Carolina Health Care press release:

    Before we are born, the developing brain creates an incredible number of neurons, which migrate to specific parts of the brain to ready us for life. Contrary to popular belief, genesis of new neurons does not stop at birth or even in childhood. In a few select areas of the brain, it can continue throughout adulthood, and is believed to be vitally important for certain forms of learning and memory, and in mood regulation. How neurogenesis is switched on and off is still not well understood, but UNC School of Medicine researchers led by Juan Song, PhD, assistant professor in the department of pharmacology, have just discovered a major clue.

    Reported as the cover story in Cell Stem Cell, the researchers identified a neurogenesis-controlling brain circuit that runs from near the front of the brain back to the hippocampus, a learning- and memory-related structure. The hippocampus is one of the major sites of neurogenesis in the adult human brain, and the circuit that Song’s team has identified regulates this neuron-producing process.

    “This circuit controls the activity of stem cells in the part of the hippocampus where neurogenesis occurs,” said Song, a member of the UNC Neuroscience Center. “Our finding ultimately could have implications for understanding and treating many brain disorders arising from aberrant hippocampal neurogenesis, including epilepsy, schizophrenia, depression, and Alzheimer’s disease.”

    Neural stem cells are like stem cells in other tissues and organs — they give birth, if needed, to new cells that replace dead or dying ones. Most of the neurons in the adult brain are wired tightly into complex circuits and are not replaced.

    The chief exception is the dentate gyrus (DG) region of the hippocampus. Neurogenesis in the DG occurs throughout adult life and supports the hippocampus’s crucial functions in storing and retrieving memories. DG neurogenesis has been linked to mood as well. In fact, scientists suspect that the mood-improving effects of antidepressant drugs and physical exercise arise at least in part from the boost they give to DG neurogenesis.

    How the brain controls DG neurogenesis, dialing it up and down when needed, is a mystery that Song and her team have been trying to solve since Song started her lab at UNC in 2013. In a study published in the journal Nature Neuroscience, for example, they found that special local hippocampal neurons called PV interneurons provide signals to DG newborn progeny that appear to be crucial for healthy neurogenesis.

    In the new study, Song and colleagues discovered that this hippocampal PV interneuron-signaling is regulated by a GABA circuit coming from the medial septum, a cluster of neurons near the front of the brain.

    “This medial septum GABA circuit works through the local PV interneurons in the hippocampus to instruct stem cells to become activated or to stay quiet,” Song said. “This GABA circuit is unique, because local PV interneurons are excited by GABA, a brain neurotransmitter that normally inhibits neuronal activity.”

    When a neural stem cell becomes activated, it begins a process of cell division that ultimately yields new neurons that connect to existing brain circuits. In a healthy hippocampus over a normal life span, neurogenesis proceeds at only a low level. Resident stem cells remain mostly in a “quiescent” state, and the population of stem cells is maintained indefinitely.

    Song and her team found that in mice, the medial septum-to-hippocampus circuit works to keep DG stem cells in this normal, low-activity state. It acts like a brake on DG stem cell activation, and thus helps maintain a healthy DG stem cell population.

    By contrast, interfering with this circuit takes off the brake completely, allowing DG stem cells to become not just active but overactive. Specifically, Song’s team found that in mice, this DG stem cell over-activation caused a burst of newly made neurons and a massive depletion of the resident DG stem cell population. Moreover, the new neurons produced in this excessive burst of neurogenesis seemed less healthy.

    “Their appearance was abnormal,” Song said. “Their dendrites — the root-like stalks that receive inputs from other neurons — were too long and had too many crossings, suggesting impaired functions. It’s likely that the production of these abnormal neurons in the hippocampus would lead to learning and memory deficits.”

    She and her team now want to determine whether the medial septum-to-hippocampus circuit can be targeted with therapies to protect DG stem cells and restore normal DG neurogenesis in cases where neurogenesis is abnormal. Alzheimer’s, schizophrenia, depression, and certain forms of epilepsy all have been linked to deficits in DG neurogenesis. There have been hints too that Alzheimer’s specifically involves losses of the medial septum neurons that connect to the hippocampus to control neurogenesis.

    “In principle, restoring the normal signals from the circuit linking the medial septum to the hippocampus may offer therapeutic potential to treat disorders that involve abnormal DG neurogenesis,” Song said.

    She and her laboratory are currently studying the function of the medial septum-to-hippocampus circuit in the context of Alzheimer’s mouse models.


  5. Study suggests bilingual preschoolers show stronger inhibitory control

    by Ashley

    From the University of Oregon press release:

    For students in preschool, speaking two languages may be better than one, especially for developing inhibitory control — the ability to stop a hasty reflexive response and instead select a more adaptive response.

    That idea isn’t new, but a University of Oregon study took a longitudinal approach to examine the bilingual advantage hypothesis, which suggests that the demands associated with managing two languages confer cognitive advantages that extend beyond the language domain.

    The study appeared in the journal Developmental Science.

    Researchers looked at a national sample of 1,146 Head Start children who were assessed for their inhibitory control at age 4, and then followed over an 18-month period. The children were divided into three groups based on their language proficiency: Those who spoke only English; those who spoke both Spanish and English; and those who spoke only Spanish at the start of the study but were fluent in both English and Spanish at the follow up assessment.

    “At the beginning of the study, the group that entered as already bilingual scored higher on a test of inhibitory control compared to the other two groups,” said the study’s lead author Jimena Santillán, a UO doctoral student in psychology at the time of the study.

    Follow-up assessments came at six and 18 months. Inhibitory control was assessed using a common pencil-tapping task, in which the participant is instructed to tap a pencil on a desk twice when the experimenter taps once, and vice-versa, requiring the student to inhibit the impulse to imitate what the experimenter does and but do the opposite instead.

    Over the follow-up period, both the bilingual group and the monolingual-to-bilingual transition group showed more rapid inhibitory control development than the group of English-only speakers.

    “Inhibitory control and executive function are important skills for academic success and positive health outcomes and well-being later in life,” said study co-author, Atika Khurana, a professor in the Department of Counseling Psychology and Human Services and scientist at the UO’s Prevention Science Institute.

    “The development of inhibitory control occurs rapidly during the preschool years,” she said. “Children with strong inhibitory control are better able to pay attention, follow instructions and take turns. This study shows one way in which environmental influences can impact the development of inhibitory control during younger years.”

    Students in this study came from low socioeconomic status families, as is typical of Head start samples. Such children are in a group known to be at-risk for poorer outcomes related to executive function skills. This population allowed the researchers to compare students from similar socioeconomic backgrounds but who had different language experiences.

    Researchers also were able to control for other variables that could be associated with inhibitory control development, such as a child’s age and parenting practices. The study’s design allowed researchers to focus on the effects of bilingual experience on inhibitory-control development during preschool years.

    Previous studies have examined the effects of bilingualism on inhibitory control, but have done so with a focus on one point in time or development and have focused on smaller samples from mostly middle class backgrounds, said Santillán, who now is a senior research manager at Harvard University’s Center on the Developing Child.

    “Many studies have addressed the bilingual advantage hypothesis,” she said. “However, the findings have been inconsistent. Part of the reason is the difficulty of randomly assigning participants to be bilingual or monolingual, which would be the ideal research design.”

    The longitudinal approach allowed researchers to see how inhibitory control changed over time for children who were developing bilingualism during the same time period, as well as for those who were already bilingual with those who remained monolingual.

    “This allowed us to get closer to capturing the dynamic nature of the development of bilingualism and inhibitory control, both of which change over time, and rule out other potential explanations for the differences observed between groups,” she said.

    It was important, she said, to focus on a sample of children who tend to be at risk for not developing inhibitory abilities at the same rate as their peers from higher socioeconomic backgrounds because of the motivation to find factors that could help buffer such children from these negative outcomes.

    “We were able to obtain evidence that bilingualism can be a protective factor that helps children develop these cognitive abilities,” Santillán said. “Provided that more research studies support our results, the findings we’ve obtained could have implications for policies related to bilingual education and could help encourage families to raise their children as bilingual.”


  6. Study links afterschool program environments to academic confidence and skills

    November 3, 2017 by Ashley

    From the New York University press release:

    Afterschool programs with positive, responsive, and organized environments can have academic benefits for students, finds a new study by NYU Steinhardt School of Culture, Education, and Human Development.

    Young people growing up in urban, low-income communities spend significant time in publicly funded afterschool programs. Unlike schools, which grow increasingly segregated and involve more individual instruction as children grow older, afterschool programs are spaces where instructors, often similar to the students in age and background, can facilitate diverse, productive interactions that help youth reach social and academic goals.

    “Because of their unique position at the juncture of school, neighborhood, and home, afterschool programs may be particularly important for youth on a path toward school disengagement or risky behaviors,” said study author Elise Cappella, associate professor of applied psychology at NYU Steinhardt and director of NYU’s Institute of Human Development and Social Change.

    Given the potential of afterschool programs to support youth in urban, low-income communities, the researchers examined the role that the afterschool classroom environment plays in terms of academic outcomes for youth with and without social and behavioral difficulties.

    The researchers used data gathered from five afterschool programs run by a single nonprofit. The 256 youth studied, ranging from third through eighth grade, were predominantly Latino and African-American.

    In both the fall and spring, the researchers collected three types of academic outcome measures from youth and staff, including reading skills, youth perceptions of their academic abilities, and academic engagement. They also conducted observations in the fall to measure the extent to which afterschool classrooms were positive, responsive, and organized, looking for factors such as supportive relationships between youth and adults, student engagement in activities, and chaos in the classroom.

    The researchers found that a positive afterschool environment – one with good social dynamics, responsive instruction, and behavior managementpredicted stronger academic skills and youth perceptions of their academic abilities across one year.

    The association between a positive environment and improvement in academic skills was magnified for students with social and behavioral difficulties, while students without these difficulties saw a greater boost in their perceptions of their own academic abilities. No significant link was found between the classroom environment in the fall and students’ academic engagement in the spring; however, in classrooms with more positive environments, youth with social and behavioral problems were more academically engaged.

    “Afterschool classrooms observed to be positive, responsive, and organized had youth with greater academic skill development over the school year. With youth in our study averaging an oral reading fluency below the 30th percentile in national norms, the potential boost may be critical,” Cappella said. “In terms of academic self-concept, one’s confidence as a learner and identity as a student grows increasingly important as children approach and enter early adolescence.”

    The researchers urge the education community to consider the role of afterschool classrooms and instructors in promoting supportive interactions and advancing academic outcomes for at-risk youth during this important transition to adolescence.


  7. Study looks at alcohol’s effect on second language ability

    October 21, 2017 by Ashley

    From the University of Liverpool press release:

    A new study published in the Journal of Psychopharmacology, conducted by researchers from the University of Liverpool, Maastricht University and King’s College London, shows that bilingual speakers’ ability to speak a second language is improved after they have consumed a low dose of alcohol.

    It is well-established that alcohol impairs cognitive and motor functions. ‘Executive functions’, which include the ability to remember, pay attention, and inhibit inappropriate behaviours, are particularly sensitive to the acute effects of alcohol.

    Given that executive functions are important when speaking a second (non-native) language, one might expect that alcohol would impair the ability to speak a second language. On the other hand, alcohol increases self-confidence and reduces social anxiety, both of which might be expected to improve language ability when interacting with another person.

    Furthermore, many bilingual speakers believe that it can improve their ability to speak a second language. The aim of this experimental study was to test these competing predictions for the first time.

    Language performance

    The researchers tested the effects of a low dose of alcohol on participants’ self-rated and observer-rated ability to converse in Dutch. Participants were 50 native German speakers who were studying at a Dutch University (Maastricht) and had recently learned to speak, read and write in Dutch.

    Participants were randomized to consume either a low dose of alcohol or a control beverage that contained no alcohol, before they chatted with an experimenter in Dutch for a few minutes. The exact dose of alcohol varied depending on participants’ body weight, but it was equivalent to just under a pint (460ml) of 5% beer, for a 70kg male.

    The chat was audio-recorded and participants’ foreign language skills were subsequently rated by two native Dutch speakers who did not know if the participant had consumed alcohol or not (observer-ratings). Participants also rated their own Dutch language skills during the conversation (self-ratings).

    The researchers found that participants who had consumed alcohol had significantly better observer-ratings for their Dutch language, specifically better pronunciation, compared to those who had not consumed alcohol. However, alcohol had no effect on self-ratings of Dutch language skills.

    Implications and Limitations

    Dr Inge Kersbergen, from the University of Liverpool’s Institute of Psychology, Health and Society, who was involved in the study, said: “Our study shows that acute alcohol consumption may have beneficial effects on the pronunciation of a foreign language in people who recently learned that language. This provides some support for the lay belief (among bilingual speakers) that a low dose of alcohol can improve their ability to speak a second language”

    Dr Fritz Renner who was one of the researchers who conducted the study at Maastricht University, said: “It is important to point out that participants in this study consumed a low dose of alcohol. Higher levels of alcohol consumption might not have beneficial effects on the pronunciation of a foreign language.”

    Dr Jessica Werthmann who was one of the researchers who conducted the study at Maastricht University, said “We need to be cautious about the implications of these results until we know more about what causes the observed results. One possible mechanism could be the anxiety-reducing effect of alcohol. But more research is needed to test this.”


  8. Study suggests brain waves reflect different types of learning

    October 20, 2017 by Ashley

    From the Massachusetts Institute of Technology press release:

    Figuring out how to pedal a bike and memorizing the rules of chess require two different types of learning, and now for the first time, researchers have been able to distinguish each type of learning by the brain-wave patterns it produces.

    These distinct neural signatures could guide scientists as they study the underlying neurobiology of how we both learn motor skills and work through complex cognitive tasks, says Earl K. Miller, the Picower Professor of Neuroscience at the Picower Institute for Learning and Memory and the Department of Brain and Cognitive Sciences, and senior author of a paper describing the findings in the Oct. 11 edition of Neuron.

    When neurons fire, they produce electrical signals that combine to form brain waves that oscillate at different frequencies. “Our ultimate goal is to help people with learning and memory deficits,” notes Miller. “We might find a way to stimulate the human brain or optimize training techniques to mitigate those deficits.”

    The neural signatures could help identify changes in learning strategies that occur in diseases such as Alzheimer’s, with an eye to diagnosing these diseases earlier or enhancing certain types of learning to help patients cope with the disorder, says Roman F. Loonis, a graduate student in the Miller Lab and first author of the paper. Picower Institute research scientist Scott L. Brincat and former MIT postdoc Evan G. Antzoulatos, now at the University of California at Davis, are co-authors.

    Explicit versus implicit learning

    Scientists used to think all learning was the same, Miller explains, until they learned about patients such as the famous Henry Molaison or “H.M.,” who developed severe amnesia in 1953 after having part of his brain removed in an operation to control his epileptic seizures. Molaison couldn’t remember eating breakfast a few minutes after the meal, but he was able to learn and retain motor skills that he learned, such as tracing objects like a five-pointed star in a mirror.

    “H.M. and other amnesiacs got better at these skills over time, even though they had no memory of doing these things before,” Miller says.

    The divide revealed that the brain engages in two types of learning and memory — explicit and implicit.

    Explicit learning “is learning that you have conscious awareness of, when you think about what you’re learning and you can articulate what you’ve learned, like memorizing a long passage in a book or learning the steps of a complex game like chess,” Miller explains.

    Implicit learning is the opposite. You might call it motor skill learning or muscle memory, the kind of learning that you don’t have conscious access to, like learning to ride a bike or to juggle,” he adds. “By doing it you get better and better at it, but you can’t really articulate what you’re learning.”

    Many tasks, like learning to play a new piece of music, require both kinds of learning, he notes.

    Brain waves from earlier studies

    When the MIT researchers studied the behavior of animals learning different tasks, they found signs that different tasks might require either explicit or implicit learning. In tasks that required comparing and matching two things, for instance, the animals appeared to use both correct and incorrect answers to improve their next matches, indicating an explicit form of learning. But in a task where the animals learned to move their gaze one direction or another in response to different visual patterns, they only improved their performance in response to correct answers, suggesting implicit learning.

    What’s more, the researchers found, these different types of behavior are accompanied by different patterns of brain waves.

    During explicit learning tasks, there was an increase in alpha2-beta brain waves (oscillating at 10-30 hertz) following a correct choice, and an increase delta-theta waves (3-7 hertz) after an incorrect choice. The alpha2-beta waves increased with learning during explicit tasks, then decreased as learning progressed. The researchers also saw signs of a neural spike in activity that occurs in response to behavioral errors, called event-related negativity, only in the tasks that were thought to require explicit learning.

    The increase in alpha-2-beta brain waves during explicit learning “could reflect the building of a model of the task,” Miller explains. “And then after the animal learns the task, the alpha-beta rhythms then drop off, because the model is already built.”

    By contrast, delta-theta rhythms only increased with correct answers during an implicit learning task, and they decreased during learning. Miller says this pattern could reflect neural “rewiring” that encodes the motor skill during learning.

    “This showed us that there are different mechanisms at play during explicit versus implicit learning,” he notes.

    Future Boost to Learning

    Loonis says the brain wave signatures might be especially useful in shaping how we teach or train a person as they learn a specific task. “If we can detect the kind of learning that’s going on, then we may be able to enhance or provide better feedback for that individual,” he says. “For instance, if they are using implicit learning more, that means they’re more likely relying on positive feedback, and we could modify their learning to take advantage of that.”

    The neural signatures could also help detect disorders such as Alzheimer’s disease at an earlier stage, Loonis says. “In Alzheimer’s, a kind of explicit fact learning disappears with dementia, and there can be a reversion to a different kind of implicit learning,” he explains. “Because the one learning system is down, you have to rely on another one.”

    Earlier studies have shown that certain parts of the brain such as the hippocampus are more closely related to explicit learning, while areas such as the basal ganglia are more involved in implicit learning. But Miller says that the brain wave study indicates “a lot of overlap in these two systems. They share a lot of the same neural networks.”


  9. Study suggests learning during development is regulated by an unexpected brain region

    October 19, 2017 by Ashley

    From the Netherlands Institute for Neuroscience – KNAW press release:

    Half a century of research on how the brain learns to integrate visual inputs from the two eyes has provided important insights in critical period regulation, leading to the conclusion that it occurs within the cortex. Scientists have now made the surprising discovery that a brain region that passes on input from the eyes to the cortex also plays a crucial role in opening the critical period of binocular vision.

    During childhood, the brain goes through critical periods in which its learning ability for specific skills and functions is strongly increased. It is assumed that the beginning and ending of these critical periods are regulated in the cortex, the outermost layer of the brain. However, scientists from the Netherlands Institute for Neuroscience discovered that a structure deep in the brain also plays a crucial role in the regulation of these critical periods. These findings, published today in the leading journal Nature Neuroscience, have important implications for understanding developmental problems ranging from a lazy eye to intellectual disability.

    Critical periods

    We can only flawlessly learn skills and functions such as speaking a language or seeing in 3D through binocular vision during critical periods of development. When these developmental forms of learning fail, lifelong problems arise.

    Scientists have been investigating the mechanisms by which critical periods are switched on and off in the hope to extend or reopen them for the treatment of developmental problems. Half a century of research on how the brain learns to integrate visual inputs from the two eyes has provided important insights in critical period regulation, leading to the conclusion that it occurs within the cortex. Neuroscientist Christiaan Levelt and his team now made the surprising discovery that a brain region that passes on input from the eyes to the cortex also plays a crucial role in opening the critical period of binocular vision.

    Using electrophysiological recordings in genetically modified mice, they showed that this brain region, known as the thalamus, contains inhibitory neurons that regulate how efficiently the brain learns to integrate binocular inputs. Levelt: “To improve developmental problems resulting in learning problems during critical periods, reinstating flexibility in the visual cortex may not be sufficient. Scientists and clinicians should not limit themselves to studying cortical deficits alone. They should also focus on the thalamus and the way it preprocesses information before it enters the cortex.”

    Albinism

    The study may also provide some hope for people with albinism, who often have limited binocular vision due to misrouting of inputs from the eyes to the thalamus. Levelt’s team found that in contrast to what is generally assumed, plasticity of binocular vision also occurs in the thalamus itself, suggesting that this might be improved in children with albinism through training.


  10. Study looks at relationship between flexibility and modularity in brain

    October 18, 2017 by Ashley

    From the Rice University press release:

    A new study by Rice University researchers takes a step toward what they see as key to the advance of neuroscience: a better understanding of the relationship between the brain’s flexibility and its modularity.

    Their open-access study appears in Frontiers in Human Neuroscience.

    Scientists are only beginning to comprehend how brains are wired, both structurally and functionally. The latest in a series of studies by Rice scientists shows that the brain’s flexibility and modularity — which researchers often study independently — are strongly related. The new study also presents a theoretical framework to explain the two processes.

    They found that flexibility, which relates to how much brain networks change over time, and modularity, which defines the degree of interconnectivity between parts of the brain responsible for specific tasks, are highly negatively correlated. In other words, people with highly modular brains that constrain tasks to the modules also show low flexibility, while people with high-flexibility brains that share tasks across the network show low modularity.

    These properties explain how participants perform in experiments, according to co-author and Rice psychologist Simon Fischer-Baum. When someone is presented with a complex task, flexibility of the brain network better explains performance than the modularity of the network. For a simple task, he said, the reverse is true, which indicates that these ways of thinking about brain organization map onto different cognitive abilities.

    But even that sliding scale only hints at the relationship between flexibility and modularity.

    “There have been a bunch of papers about the flexibility of the network and how that relates to cognition and a bunch of other papers about modularity and its relation to cognition, but nobody’s really explored whether these things are tapping into different aspects of cognition or if they’re two sides of the same coin,” said Fischer-Baum, who was the lead faculty member on the study in collaboration with Rice psychologist Randi Martin and biophysicist Michael Deem.

    “People can be described in terms of how flexible their brain networks are: how frequently brain regions change the modules they’re assigned to or how stable the modules stay over time,” Fischer-Baum said. Regions of the brain with higher flexibility are those typically associated with cognitive control and executive function, the processes that control behavior. Regions with lower flexibility are those involved in motor, taste, vision and hearing processes.

    The researchers took two paths to map the modules and thought processes of 52 subjects ranging in age from 18 to 26; 31 percent of the participants were male and 69 percent were female.

    First, the subjects underwent resting-state functional magnetic resonance imaging (fMRI), which detected blood oxygen levels to track activity and measure modularity (the likelihood of connections within modules of the brain) and flexibility (how frequently regions switch allegiance from one module to another).

    Second, the subjects took a battery of six cognitive tests to assess their performance on simple and complex tasks.

    Data from both paths had previously been used to show that brain modularity correlates positively with performance on simple tasks and negatively with performance on complex tasks. The question that remained was how modularity relates to other measures of network organization, like flexibility, and how flexibility relates to cognitive processing as a whole. The goal of the Rice study was to analyze the entire brain network rather than individual components.

    “Cognition is complex,” Fischer-Baum said. “Any task relies on multiple areas of the brain doing different functions and communicating with each other. We have to be able to articulate why, for a given task, it’s good to have a particular type of brain organization.”

    Participants were given a series of common cognitive psychology experiments, which yielded composite scores for simple and complex behaviors that aligned with the fMRI results. Participants who showed high flexibility fared best on complex tests that required the ability to quickly switch between tasks and draw upon working memory. One, for example, presented them a square or triangle in blue or yellow and required the participants to respond to a cue about either the color or shape of the object.

    Those who scored higher on the modular scale excelled on tasks with more limited behavioral requirements, like a traffic-light test that required them to hit a button as quickly as possible when they saw a light turn from red to green and measured their response times.

    The researchers noted it would be incorrect to think that modularity and flexibility simply measure the same property. Because they make independent contributions to performance, the researchers theorize they are “likely to link to different cognitive processes.”

    They also theorized that learning a skill may account for variation within individuals between modularity and flexibility. The researchers wrote that during the initial stages of learning, even a simple skill may employ cognitive controls usually required for complex tasks. But as the task is learned and becomes simpler, flexibility decreases and modularity increases.

    Fischer-Baum said it’s best to think of flexibility and modularity as continuously variable rather than fixed traits. “I don’t think we know how this changes over time, but it seems likely that it changes with experience, and even over the course of a day.

    “This broad division between complex and simple tasks is a first pass at the problem,” he said. “It’s not just that having a modular brain is good, or having a flexible brain is good. We want to know what they’re good for and the timescales at which these variables have an impact.”