Where in the brain are words?

How are words represented in the brain? Are they listed alphabetically, categorized by meaning or categorized by the way they sound? The emerging technologies of brain imaging have now made it possible to examine the neural representation of such concepts as simple nouns in the human brain. By combining brain imaging and machine learning techniques, neuroscientists Marcel Just and Vladimir Cherkassky and computer scientists Tom Mitchell and Sandesh Aryal recently determined how the brain arranges noun representations.

"In effect, we discovered how the brain's dictionary is organized," said Just, the D.O. Hebb Professor of Psychology and director of the Center for Cognitive Brain Imaging. "It isn't alphabetical or ordered by the sizes of objects or their colors. It's through the three basic features that the brain uses to define common nouns like apartment, hammer and carrot."

As the researchers report January 12 in the journal PLoS One, the three codes or factors concern basic human fundamentals:

1. how you physically interact with the object (how you hold it, kick it, twist it, etc.);


2. how it is related to eating (biting, sipping, tasting, swallowing); and


3. how it is related to shelter or enclosure.
   

The three factors, each coded in three to five different locations in the brain, were found by a computer algorithm that searched for commonalities among brain areas in how participants responded to 60 different nouns describing physical objects. For example, the word apartment evoked high activation in the five areas that code shelter-related words.

In the case of hammer, the motor cortex was the brain area activated to code the physical interaction. "To the brain, a key part of the meaning of hammer is how you hold it, and it is the sensory-motor cortex that represents 'hammer holding,'" said Cherkassky, who has a background in both computer science and neuroscience. Similarly "shelters" activated the
parahippocampal place area of the brain. The eating factor activates areas associated with face-related actions like chewing or biting. As you can see below, the "tools of manipulation" and "eating" words are represented in the left hemisphere probably because most of the particpants were right handed for tool use and feeding.

Each noun is represented as a mixture of factors. For example "apple" being both an object of eating and an object of manipulation activates multiple brain areas to different degrees producing a pattern of activation or a "code". Thus the meanings of concrete nouns can be semantically represented in terms of the activation codes in the cortex.

Interestingly, researchers found that word length was also a factor that was features in this activation code for each written word. The word length factor presents an opportunity to separate a low-level, perceptual feature of the printed word from the highlevel, semantic object features (encoded by the manipulation, eating, and shelter factors). The word length factor appeared to represent the width or number of letters of the printed word.

The research also showed that the noun meanings were coded similarly in all of the participants' brains. "This result demonstrates that when two people think about the word 'hammer' or 'house,' their brain activation patterns are very similar. But beyond that, our results show that these three discovered brain codes capture key building blocks also shared across people," said Mitchell, head of the Machine Learning Department in the School of Computer Science.

This study marked the first time that the thoughts stimulated by words alone were accurately identified using brain imaging, in contrast to earlier studies that used picture stimuli or pictures together with words. The programs were able to identify the thought without benefit of a picture representation in the visual area of the brain, focusing instead on the semantic or conceptual representation of the objects. Thus this is important in understanding how the brain reads and comprehends language.

Although nouns that related to human beings such as 'spouse' or 'boyfriend' or even 'person' were not included in the study, some human dimension is expected to be part of the brain's coding of nouns, in addition to the three dimensions the researchers found. With psychiatric and neurological illnesses, the meanings of certain concepts are sometimes distorted. These new techniques make it possible to measure those distortions and point toward a way to 'undistort' them. For example, a person with autism might have a weaker coding of social contact.

Reference: Just et al. A Neurosemantic Theory of Concrete Noun Representation Based on the Underlying Brain Codes.PLoS ONE, 2010; 5 (1): e8622 DOI:10.1371/journal.pone.0008622

Why Learning by Doing is the Best.

Ever wondered why learning by doing is so successful? Exciting new research on the rewiring processes that take place in the brain during motor learning now offers some clues. As it turns out, lots of new connections are formed between neurons when we learn a motor task and this learning is not forgotten because this change is permanent. Here is more....

The study led by researchers at the University of California, Santa Cruz, published in the science journal Nature, reports that new connections begin to form between brain cells almost immediately as animals learn a new task. The researchers studied mice as they were trained to reach through a slot to get a seed. They observed rapid growth of structures that form connections(called synapses) between nerve cells in the motor cortex, the brain layer that controls muscle movements.

"We found very quick and robust synapse formation almost immediately, within one hour of the start of training," said Yi Zuo, assistant professor of molecular, cell and developmental biology at UCSC.

Zuo's team observed the formation of structures called "dendritic spines" that grow on pyramidal neurons in the motor cortex. The dendritic spines form synapses with other nerve cells. At those synapses, the pyramidal neurons receive input from other brain regions involved in motor memories and muscle movements. The researchers found that growth of new dendritic spines was followed by selective elimination of pre-existing spines, so that the overall density of spines returned to the original level.

"It's a remodeling process in which the synapses that form during learning become consolidated, while other synapses are lost," Zuo said. "Motor learning makes a permanent mark in the brain. When you learn to ride a bicycle, once the motor memory is formed, you don't forget. The same is true when a mouse learns a new motor skill; the animal learns how to do it and never forgets."

The study used a noninvasive imaging technique that enabled them to view changes in individual brain cells of the mice before, during, and after the mice were trained in the seed-reaching task.

"We were able to follow the same synapses over time, which had not been done before in a motor learning study," Zuo said. "We showed that structural changes occur in the brain at a much earlier stage than people had believed."

Results from the study suggested that the newly formed dendritic spines are initially unstable and undergo a prolonged selection process during the course of training before being converted into stable synapses.

When previously trained mice were reintroduced to the reaching task four months later, their skill at the task remained high, and images of their brains did not show increased spine formation. When previously trained mice were taught a new skill, however, they showed enhanced spine formation and elimination similar to that seen during the initial training. Furthermore, spines that had formed during the initial training persisted after the remodeling process that accompanied the learning of a new task.

These findings suggest that different motor behaviors are stored using different sets of synapses in the brain.

Understanding the basis for such long-lasting memories is an important goal for neuroscientists.

One of the questions Zuo would like to explore in future studies is how these findings apply to different types of learning. "In China, where I grew up, we memorize a lot in school. What are the changes that take place in the brain during learning and memorizing, and what are the best ways to consolidate those memories? We don't really know the best way to learn and memorize," she said.

What we do know, however, is that knowledge obtained from rote memorization is easily forgotten whereas as learning by doing has been proven to have the best retention rates. Learning through discussion, participation and simulation comes a close second. It is likely that greater involvement of our many different senses during the "doing" process of active learning plays an important role in this phenomenon. Additionally, as the above study suggests, we may be just naturally wired to learn by doing. This would explain why we have such a lot of mental resources devoted to learning through "mimicking". A trait that has been preserved from mice to humans and that is observed as early as infancy.

Reference: University of California - Santa Cruz (2009, November 30). New brain connections form rapidly during motor learning. ScienceDaily. Retrieved November 30, 2009, from http://www.sciencedaily.com/releases/2009/11/091129153359.htm

Learning Math

The brain has an innate ability for estimating quantity as seen in babies and non-humans. However, the human ability to match specific quantities with number symbols, a skill required for doing arithmetic, is a developed skill. It takes years for children to master the ins and outs of arithmetic. New research indicates that this learning process triggers a large-scale reorganization of brain processes involved in understanding written symbols for various quantities.

It is now known from brain imaging studies that the two distinct circuits are involved during math. One circuit gives names to numbers and carries out exact calculations. This shows up on brain scans as large and strictly left-lateralized activation in the left inferior frontal lobe. A second circuit operates intuitively and is used for estimating quantities and other numerical relationships. This one shows up on brain scans as bilateral activation of the inferior parietal lobule. Research also indicates that the cerebellum plays an important role in single digit addition and comparison tasks of math cognition, but the function of cerebellum in math cognition cooperates with the frontal lobe to perform the simple math task.

While this is true for adults, children, have been observed to recruit more of their pre-frontal cortex and depend less on parietal cortex for math tasks. It is generally thought that the parietal cortex takes time to mature and as it does so mental math becomes earier for children. Interestingly, we also find that math-gifted adolescents show more bilateral activation of frontal and parietal lobes. They are able to recruit the right hemisphere possibly for the imagery required in spatial math problems. The bilateral nature of this activation indicates enhanced interhemispheric connectivity via the corpus callosum. Programs designed to develop the whole brain would therefore be likely to improve mathematical ability as would programs that stimulate the frontal cortex.

The frontal areas of the brain, especially the prefrontal cortex houses cognitive skills as working memory and executive function. Both executive function and working memory have been found to be important foundational cognitive skills for mathematical ability. For instance a study of 141 preschoolers from low-income homes has found that a child whose IQ and executive functioning were both above average was three times more likely to succeed in math than a child who simply had a high IQ.

When math test scores in individuals who had higher levels of working memory with those who had less were compared, it was found that individuals with higher levels of working memory have superior memory and computational capacity. However, in a high pressure testing situation, it turns out that the subjects with higher working memory levels performed very poorly—that is, the subjects with the greatest capacity for success were the most likely to “choke under pressure”. This has important implications for assessment such as the COGAT test. Also, as more schools start emphasizing state-exam based curricula, these studies will become increasingly relevant and important for the development of exams and training regimens that will ensure optimal performance, especially by the most promising students.

The type of working memory involved in solving math problems may be affected by the way the problems are presented. When arithmetic problems are written horizontally, more working memory resources related to language are used. However, when problems are written vertically, visuo-spatial resources of working memory are used.

Resoning ability is another cognitive domain builds the capacity for logical thought, reflection, explanation, and justification. Math is about using logic to explain and justify a solution to a problem. It is the mental muscle necessary to successfully explore puzzles. It can also extend something known to something not yet known. Therefore developing good reasoning skills is also important in math ability.

The fact that executive function, working memory and other cognitive abilitiesare significantly related to early math performance, even in children as young as pre-schoolers, suggests that if we can improve the capacity for these skills, we can improve their academic performance.

Infact, this is exactly what we have demonstrated with Neuropath Learning programs. We recently showed that third grade students graduating our programs perform significantly better on state standardized test of math proficiency when compared to students who have not used our programs. Because Neuropath Learning programs build cognitive skills such as visual-spatial skills, reasoning skills, attention skills, executive function skills and working memory skills we have been able to boost mathematical acheivement without necessarily teaching third grade mathematics. Such is the power of cognitive training! For information on our programs visit us at http://www.neuropathlearning.com/ or send me an e-mail to npl@neuropathlearning.com.


References:

Clancy Blair, Hilary Knipe, David Gamson (2008) Is There a Role for Executive Functions in the Development of Mathematics Ability? Mind, Brain, and Education, 2 (2): 80 – 89.

Beilock, S. L. (2008). Math performance in stressful situations. Current Directions in Psychological Science, 17, 339-343.

Michael W. O’Boyle, et al., (2005) Mathematically Gifted Male Adolescents Activate a Unique Brain Network During Mental Rotation, Cognitive Brain Research, 25: 583-587.

Holloway, I.D. & Ansari, D. (2009) Mapping numerical magnitudes onto symbols: The numerical distance effect and individual differences in children’s math achievement. Journal of Experimental Child Psychology, 103, 17-29.

Shigang Feng1, Yaxin Fan1, Qingbao Yu1, Qilin Lu1 and Yi-Yuan Tang (2008) The cerebellum connectivity in mathematics cognition. BMC Neuroscience 9(Suppl 1):155.

S Dehaene (1997) The number sense: How the mind creates mathematics New York, NY: Oxford University Press

Sensory Integration

Sensory processing or "sensory integration" is a term that refers to the way the nervous system receives messages from the senses and turns them into appropriate motor and behavioral responses. Whether you are biting into a hamburger, riding a bicycle, or reading a book, your successful completion of the activity requires processing sensation or "sensory integration."

Sensory Processing Disorder (SPD, formerly known as "sensory integration dysfunction") is a condition that exists when sensory signals don't get organized into appropriate responses. Pioneering occupational therapist and neuroscientist Dr Jean Ayres, likened SPD to a neurological "traffic jam" that prevents certain parts of the brain from receiving the information needed to interpret sensory information correctly. A person with SPD finds it difficult to process and act upon information received through the senses, which creates challenges in performing countless everyday tasks. Motor clumsiness, behavioral problems, anxiety, depression, school failure, and other impacts may result if the disorder is not treated effectively.

Sensory processing disorder can affect people in only one sense–for example, just touch or just sight or just movement–or in multiple senses. One person with SPD may over-respond to sensation and find clothing, physical contact, light, sound, food, or other sensory input to be unbearable. Another might under-respond and show little or no reaction to stimulation, even pain or extreme hot and cold. In children whose sensory processing of messages from the muscles and joints is impaired, posture and motor skills can be affected. These are the "floppy babies" who worry new parents and the kids who get called "klutz" and "spaz" on the playground. Still other children exhibit an appetite for sensation that is in perpetual overdrive. These kids often are misdiagnosed - and inappropriately medicated - for ADHD. Research by the SPD Foundation indicates that 1 in every 20 children experiences symptoms of Sensory Processing Disorder that are significant enough to affect their ability to participate fully in everyday life. Symptoms of SPD, like those of most disorders, occur within a broad spectrum of severity. While most of us have occasional difficulties processing sensory information, for children and adults with SPD, these difficulties are chronic, and they disrupt everyday life.

Children with poor sensory integration often have poor school achievement, particularly in arithmetic. Parham (1998) investigated the relationship between sensory integration and school achievement in children aged between 6 and 10 years, 32 were learning-disabled and 35 were non-disabled. Sensory integration was significantly related to school achievement and this relationship was retained over a 4-year period, even when children of equal IQ were compared. In fact, research indicates that sensory integrative problems are found in up to 70% of children who are considered learning disabled by schools. It is also very common among children with Autism, ADHD.

Typically, Sensory Integration therapy, provided by occupational therapists (OT), does not focus on training specific cognitive skills. However, significant research now reveals that the majority of sensory integration disorders are caused by cognitive weakness resulting from a poorly connected prefrontal cortex. The most evolved part of the brain known as the Prefrontal Cortex (PFC) is where all of our sensory information is pulled together to allow us to make decisions about how to respond to any change in our environment. The PFC has two way connections to the parts of the brain involved in the processing of visual, auditory and somatic sensory information. Therefore, although traditional therapy exercises may be helpful for general motor skills re-training, any long-term treatment for sensory integration dysfunctions must include targeted, integrative cognitive skills assessment and training. Neuropath Learning programs can facilitate sensory processing ability by developing the wiring/connectivity/functioning of the pre-frontal cortex. The interactive activities in our programs provide visual processing and auditory processing assessment and training necessary to improve these skills. Improvement of one sensory processing mode eg., vision or hearing is known to help improve sensory processing of another modality like touch or smell. This is because our brains are wired for our senses to work together. Within our brain there are some areas that are relatively selective for visual, auditory, or tactile motion processing, but other areas that seem to process various combinations of inputs (mulitsensory areas). We therefore recommend our programs be used in conjunction with traditional OT programs for young children. Visit our website at http://www.neuropathleaning.com/ to learn more.

References

1. Sensory Processing Disorder Foundation http://www.spdfoundation.net/index.html
   
2. Parham, L. D., 1998. The Relationship of Sensory Integrative Development to Achievement in Elementary Students: Four-Year Longitudinal Patterns. Occupational Therapy Journal of Research; 18 (3), page 105
   
3. Henk J. Groenewegen and Harry B. M. Uylings (2000) The prefrontal cortex and the integration of sensory, limbic and autonomic information. Progress in Brain ResearchVolume 126, Page 3

How Fast Can The Brain Re-wire?

The brain is in various states of readiness to re-wire in response to a particular learning experience. Changes at the chemical level, such as an alteration of neurotransmitter release, uptake, production, are very rapid. Changes at the level of connectivity between neurons such as increase in numbers of synapses (connections), strengthening of synapses and remodeling of synapses is also quite rapid. Re-wiring processes that incorporate newly born neurons into a pathway are somewhat slower to occur – these are the changes that lead to enlargement of brain areas that a heavily used for specific tasks.

Using a new brain scanning technique called Diffusion Tensor MRI, scientists can now trace connections between different brain regions and recent observations demonstrate that the microstructure of the brain can change in mere hours. After subjects were asked to train on a visual/spatial task, structural and functional changes were detected as soon as two hours of training. The spatial learning task involved playing a highly engaging race-track video game, going over the same virtual race track 16 times. Each time the subjects circled the track, the time they took to complete it decreased. At the end of the two hours, microstructure of the hippocampus, motor and visual areas of the brain had changed! These microstructural changes involved changes in connectivity between neurons such as increased synaptic density, formation of new synapses and formation of new dendrites.

But neurons are not the only brain cells that adapt to learning. The other type of cell present in the brain is the “glial cell”. Glial cells are essentially support cells – meaning they support the function and needs of neurons. Scientists recently found that new glial cells, which are produced in the brain throughout life, release a type of chemical that acts as a brain fertilizer - facilitating the growth and connectivity of neurons in the brain. This response of new glial cells was demonstrated to produce improved cognitive function in aging brains.

This all makes sense when you think of the speed at which cognition and attention have been shown to improve with training. We have witnessed some pretty remarkable changes in academic performance, social attitudes and behaviors of children using Neuropath Learning programs in just a matter of months which amounted to a total time of 8-10hours of interaction with our learning system. We have always found this pretty mindboggling to explain but in light of Michael Posner's work, I reported in an earlier post and this recent data we now know that the brain can and does adapt functionally and structurally at a rapid pace producing such dramatic outcomes.


References:

1. American Friends of Tel Aviv University (2009, August 17). Window Into The Brain: Diffusion Imaging MRI Tracks Memories And May Detect Alzheimer's At Early Stage. ScienceDaily. Retrieved August 19, 2009, from http://www.sciencedaily.com/releases/2009/08/090812145022.htm

2. University of California - Irvine (2009, July 22). Neural Stem Cells May Rescue Memory In Advanced Alzheimer's, Mouse Study Suggests.ScienceDaily. Retrieved August 19, 2009, from http://www.sciencedaily.com/releases/2009/07/090720190726.htm

Response to Intervention: Get in the Zone!

The Response to Intervention (RTI) model gained credibility in recent years as an eligibility model for special education services. But RTI is also a useful approach to providing data-based decision-making for any students who may be in need of extra interventions for improving their performance. Since data driven decision making is one of the key reforms emphasised by the Federal government's stimulus funding guidelines, RTI is currently a hot topic.

The RTI model comprises of 3 tiers, universal interventions (green zone), group interventions (yellow zone) and individual interventions (red zone). At each tier, assessments and interventions are offered within general education classrooms to identify and correct potential learning issues. The goal is twofold: to prevent children from being channeled into special education programs and to help mainstream students already in special programs.

At each zone the following questions are asked:
1. What is the problem?
2. Why does the problem exist?
3. What should be done to address the problem?
4. Did the intervention work and what’s next?

Neuropath Learning programs are designed to help teachers and school administrators implement practical RTI programs in elementary schools. For example, our programs Early Mind Matters and Knowledge First, can help with both assessment and intervention at each level. Since the program does all the work, it is a very practical universal intervention to offer school wide as a preventive measure. The multimodal differentiated instruction and comprehensive assessment covers a broad range of possible learning issues. The programs are able to clearly and precisely define the cognitive gaps that are leading to various learning issues. The cognitive challenges in the learning activities then train the brain to develop the cognitive skills found to be weak. This type of cognitive training facilitates academic achievement and the benefits of this training have been shown to be long lasting. Data is collected in real time as the student interacts with the program and the teacher and principal can view this data distribution in the context of individual performance, class performance and school performance. The students progress through the programs at their own pace, once one program is completed they can move on to more advanced programs. The programs can track individual student progress and measure learning. Whats more, our programs are fully customizable for addressing special needs of certain groups of students with the same learning issue or individuals with who need tailor made interventions. Thus offering solutions for students in the green zone and red zones. This is the power of our technology. We like to think we offer learning solutions and not just sell software to schools. Our goal is to partner with schools to help students reach their full potential and we strive to make sure our programs are used correctly to obtain maximum benefits.

If you are wondering, "well that's great news for learning issues, but what do I do about behavioral issues?" you should read the previous post where I explain how Neuropath Learning programs address both learning and behavior issues at the same time using executive function training activities. Here is the link: http://neuropathlearning.blogspot.com/2009/08/killing-two-birds-with-one-stone.html

Be sure to check out our website, http://www.neuropathlearning.com/, for more information, interactive demos, sample charts and success stories.

KILLING TWO BIRDS WITH ONE STONE

I just returned from the WASA/OSPI Special Ed workshop and it was interesting to see how educators separate learning issues from behavior issues. And its not just educators, domains of cognition and emotion are often treated as non-overlapping entities across the board. This is quite surprising to me because if you think about it in neurological terms, no such distinction remains since both are controlled by the same brain networks. Both Cognition and Executive funtions (EF) are housed in the prefrontal cortex of the brain. Engaging in tasks that activate the prefrontal cortex can develop both cognition (including social cognition), emotional regulation and behavioral responses. Neuropath Learning Programs offer creative problem solving activities that train cognitive skills plus develop executive function and thus have been shown to improve both learning and behavioral outcomes. Essentially killing two birds with one stone - or blurring the line between them.

Executive functioning refers to our ability to be able to make and carry out plans, direct our attention, focus and also to control our internal states: our impulses and emotions and to be able to switch from one task to another. In other words it is a key part of our ability to self-regulate our behavior, mind and emotions.

However, EF comprises not only effortful control and cognitive focus but also working memory and mental flexibility—the ability to adjust to change, to think outside the box. These are the uniquely human skills that, taken together, allow us keep our more impulsive and distractable brain in check. New research shows that EF, more than IQ, leads to success in basic academics like arithmetic and grammar. It also suggests that we can pump up these EF skills with regular mental exercise, just as we do with muscles.

Studies conducted with preschool aged children showed that those kids educated using techniques that help to develop executive function performed far better than their conventionally educated peers. What’s more the EF groups significantly outperformed their matched peers in all areas including their subsequent ability to learn to read, write and correctly perform mathematical functions when they reached kindergarten.

Here are some examples of the learning activities in the EF curriculum. Instead of keeping the classroom quiet, kids are actually taught and encouraged to talk to themselves, privately but aloud, as a way of helping them exert mental control. In one exercise, for example, the kids have to match their movements to symbols. When the teacher holds up a circle they clap, with a triangle they hop, and so forth. The kids are taught to talk themselves through the mental exercise: "OK, now clap." "Twirl now." This has been shown to flex and enhance the brain's ability to switch gears, to suppress one piece of information and sub in a new one. It takes discipline; it's the elementary school equivalent of saying "I really need to stop thinking about next week's vacation and focus on this report."

Here's another example from the classroom. Children tell stories to one another, but kids being kids, they all want to be the storyteller; none wants to just sit and listen. But the reality is that only one can tell a story at a time, so the designated listeners hold a picture of an ear, a prop to remind them that they are waiting their turn to talk. This helps them learn to control their natural instinct to talk out of turn. Eventually the props and private chatter are not needed, but in the beginning they help cognitively immature children stretch their executive muscles.

Dramatic role playing is a cornerstone of the EF philosophy. The preschoolers, all four and five years old, actually design the play's action by themselves. For example: "Let's pretend you're the mommy and I'm the baby. I'll get sick, and you'll need to take me to the doctor." Then they act it out, solving problems along the way. The idea is that play of this kind promotes the internalization of rules and expectations and demands mental discipline to stay in character—all cognitive challenges. Importantly, these exercises were not tacked on as a separate teaching, but rather were integrated into every activity of the child's day, from reading to math.

This however, is a vast oversimplification of a curriculum that has taken years to develop and is grounded in rigorous scientific studies of children's brain development. Even though the activities may seem frivolous studies showed that preschoolers with sharper executive capability as a result of such a curriculum outperform their more traditional learning peers in basic skills, especially mathematics, when they hit kindergarten. In other words, early exposure to dramatic play and cognitive games better prepares kids for mastery of traditional academics.

This new thinking has the potential to be transformational if the powers that be are willing to embrace the realities of this data. If you think in terms of Executive function there is no difference in interventions for WON'T DO kids and CAN'T DO kids.

Neuropath Learning has long recognized the importance of executive function and has applied this knowledge to designing all its learning and assessment programs. Our learning activities are real world simulations of these same types of EF activity examples. This is why, not only are they successful they are also fun and children love using them. These programs are easy to use at home to complement school curriculum. So get your child on our learning path today!

Ref: Is EF the New IQ?