Showing posts with tag processing Show all posts >
On October 30th, noted neuroscience researcher and co-founder of Scientific Learning, Dr. Paula Tallal, conducted a live webinar titled “What do Neuroscientists Know About Learning That Most Educators Don’t?” In her presentation, Dr. Tallal discussed her original research on auditory processing, its relationship to language development, and the far-reaching effects that deficiencies in those areas can have on learning.
Research continues to support the hypothesis that difficulty discriminating between small changes in sound is at the heart of learning problems both in students who have a diagnosed difficulty and those who do not. Dr. Tallal described how oral language is the foundation for learning and for most successful educational outcomes, adding that oral language itself is dependent on the brain’s ability to discriminate and process auditory information. Children who have difficulty perceiving the many subtleties of language find the deck stacked against them in their educational careers. They can experience a variety of impediments to learning, including:
Students with this subtle level of auditory processing problem need specific differentiation that is not possible in most classrooms. The good news, as Dr. Tallal describes, is that modern technology can be used to address the difficulties these children face and help bridge these skill gaps. In fact, it is this level of research and development that informed the development of Scientific Learning’s software programs, including Fast ForWord.
To close, Dr. Tallal took questions from the educators relating to how these insights can be used to improve educational outcomes in all classrooms. Teachers left this insightful webinar with practical strategies that can be used to help learners of all abilities.
Attend one of our popular webinars with thought leaders in learning. Live and pre-recorded webinars are available. Register today!
Have you ever wondered why some children seem to learn to read so effortlessly and others struggle? Have you ever seen a child who memorizes poems, math facts, and the alphabet without even trying? Yet at the same time you might have also known another child who had trouble just remembering their own phone number or address. There are all sorts of reasons that learning—and reading—is easy for some children and hard for others, and believe it or not, it rarely has anything to do with intelligence.
Just as some children are good athletes from the time they are very young, others are great at music or art. We tend to think of art, music and athletics as skills or talents. But actually there are underlying cognitive abilities that enable those talents. For athletics, good hand-eye coordination and quickness can be keys to success. For music, certainly the ability to perceive tones is essential. For art, excellent visual memory is helpful.
It turns out that learning to read also requires some underlying cognitive skills. Children are not born good readers, of course; reading has to be taught. And for a child to be able to learn to read, four core cognitive capacities are needed: memory, attention, sequencing, and processing efficiency (speed and accuracy). It is helpful to tease out each one of these and explain the importance in learning to read.
Memory – Scientists refer to the kind of memory that is important for learning to read as “working memory.” It is the kind of short term memory that enables you to read this blog and remember what was written a few paragraphs earlier. When children have problems with working memory, reading can be very difficult. A child might have trouble remembering what sounds the letters of the alphabet stand for when they are first starting to read and so have a devil of a time learning to decode. Later in school the child with working memory problems might have trouble remembering what they read just a few sentences earlier and so re-read the same passages over and over again. How do you know if a child has working memory problems? Look for trouble following commands or remembering details of instructions or stories.
Attention – Learning of any kind requires good attentional skills. A student needs to be able to pay attention when the teacher is talking and ignore random noises in the room. A student also needs to learn to pay attention during reading. In learning to read, students need to pay attention to the letters and attend carefully to the sounds they represent. Later in school, students who have trouble attending are often those who can’t stick with a reading assignment. What to look for: the child reads a few sentences or paragraphs and then looks around the room, drops a pencil, or gets up out of a chair. It can take a child who has problems sustaining his attention a very long time to finish reading assignments.
Sequencing – Reading requires the ability to sequence letters into words (“saw” versus “was”) and grammatical endings (“the boy runs” versus “the boys run”), and words into sentences (“the dog chased the boy” versus “the boy chased the dog”). It is easy to see that when children have trouble sequencing, they will misunderstand what they read. Some children find sequencing things they hear very hard because the information is so fleeting.
Processing speed and accuracy – Scientists refer to the way the brain handles information as “processing.” Parents may have heard the terms “auditory processing” or “visual processing”. Those terms refer to the way the brain perceives and attaches meaning to information coming in from hearing or vision. Some students are inherently good at processing visual information. Those students seem to learn well visually and are very good at perceiving visual cues, like picking up on facial expressions or remembering how words look when they are spelled. However, some of those students may not process auditory information as well. They might frequently misunderstand words spoken to them or “tune out” when people talk to them. Students with auditory processing inefficiencies might also seem “slow” to respond when others are talking to them. Certainly, if a child has trouble hearing the difference between the vowels in “bit” and “bet,” it makes sense that learning the correspondence between letter and sound will be difficult. In fact, there is a great deal of research indicating that children with auditory processing inefficiencies find learning to read very difficult.
We tend to think that reading is a visual skill that depends primarily on linking letters to sounds. That has led us to expect that reading problems must be due to either difficulties with recognizing the letters or matching those letters to their appropriate sounds. However, we now know that a core set of underlying cognitive skills: memory, attention, processing speed or accuracy, and sequencing underlie the ability to learn to read and later to read to learn.
Berninger, Virginia. et al. Relationship of Word- and Sentence-Level Working Memory to Reading and Writing in Second, Fourth, and Sixth Grade. Language, Speech and Hearing Services in Schools, vol. 41, 179–193. 2010.
Bishop, Dorothy and Snowling, Margaret. Developmental dyslexia and specific language impairment: same or different? Psychological Bulletin, vol. 130, 858-886. 2004.
Burns, Martha. Auditory Processing Disorders and Literacy. In Geffner, D and Swain, D. Auditory Processing Disorders. Plural Publications.
Caretti, Barbara. et al. Role of working memory in explaining the performance of individuals with specific reading comprehension difficulties: A meta-analysis. Learning and Individual Differences, vol. 19, 246–251. 2009.
Gaab, Nadine. Neural correlates of rapid auditory processing are disrupted in children with developmental dyslexia and ameliorated with training: An fMRI study. Restorative Neurology and Neuroscience, vol. 25, 295–310. 2007.
Stevens, Courtney et al. Neural mechanisms of selective auditory attention are enhanced by computerized training: Electrophysiological evidence from language-impaired and typically developing children. Brain Research, vol. 1205, 55-69. 2008.
Stevens, Courtney et. al. Neurophysiological evidence for selective auditory attention deficits in children with specific language impairment. Brain Research, vol. 1111-1. 2006.
Attend one of our popular webinars with thought leaders in learning. Live and pre-recorded webinars are available. Register today!
Dyslexia is thought to affect a high percentage of people. The condition can be caused by biological changes during brain development (known as developmental dyslexia) or by environmental effects such as illness or injury (known as acquired dyslexia). In their recent article published in the Proceedings of the National Academy of Sciences, Nora Maria Raschle, Jennifer Zuk and Nadine Gaab cite estimates that developmental dyslexia affects between 5 and 17% of all children. (2012) They further outline how it can have detrimental effects on a child’s life both inside the classroom as well as beyond.
For these reasons, educators and researchers have placed intervention strategies for developmental dyslexia very high on their priority list.
While much progress on such interventions has occurred in the area of helping individuals with developmental dyslexia once they have been diagnosed, other research is delving into identifying the neurological and physiological differences between brains that develop the condition and those that do not.
To find out if there are identifiable predictors of developmental dyslexia, Raschle, Zuk and Gaab examined the functional brain networks during phonologic processing in 36 pre-reading children with an average age of 5.5 years. That is they were looking for brain differences even before any of the children had learned to read since previous brain studies of dyslexia have been conducted on individuals after they have begun to read, albeit poorly. All of the subjects were of a similar socioeconomic status; most came from homes with relatively high SES and strong language skills. These are the type of home environments that typically result in the development of good language and reading skills.
The only substantive difference between the groups in this study was that half of the subjects had a family history of developmental dyslexia, while the other half did not.
Interestingly, the 18 children with a family history of dyslexia scored significantly lower than those who had no family history on a number of standardized assessments, including:
Not only did the research team examine the two groups’ performance on these evaluations, but they also used functional magnetic resonance imaging (fMRI) scanning to identify what was happening in the brains of each learner during the examinations.
Brain activity in the left lingual gyrus as well as the temporoparietal brain areas correlated with phonological processing skills. Interestingly, the team discovered that members of the group with a family history of dyslexia showed a reduced activation in these areas even before learning to read. Their discoveries suggest that the left temporoparietal region of the brain in this group reflect an inability to map phonemes to graphemes. In other words, their brains simply were not adequately developed to match language sounds with their written counterparts. In addition, this same region of the brain – also known as the “visual word form area” – seems to be involved in processing words during reading in both children and adults.
The authors unequivocally state, “Developmental Dyslexia can have severe psychological and social consequences, potentially negatively impacting a child’s life.” All too often, we identify learning disabilities much too late. In the case of dyslexia, we might make such a diagnosis and begin interventions halfway through elementary school, but by then we have much catching up to do. If these students’ vocabulary skills and motivation to read have already been compromised, the climb back may be much more difficult than if had the situation been identified earlier.
Research like that of Raschle, Zuk and Gaab will help us begin to address learning disabilities at the neurological and physiological levels much earlier in life. Through very early diagnosis and intervention, we may one day be able to more effectively ameliorate – and maybe even eliminate – the distressing experience of developmental dyslexia.
Read this study to learn how Fast ForWord helped significantly improve reading skills in children with dyslexia.
Gaab et al., 2007, "Neural correlates of rapid auditory processing are disrupted in children with developmental dyslexia and ameliorated with training: An fMRI study,"; Restorative Neurology and Neuroscience 25, 295-310.
Raschle, N. M., Zuk, J. and Gaab, N., 2012, "Functional characteristics of developmental dyslexia in left-hemispheric posterior brain regions predate reading onset." PNAS, v. 109, p. 2156–2161.
Attend one of our popular webinars with thought leaders in learning. Live and pre-recorded webinars are available. Register today!
One of my favorite webinar presenters here at Scientific Learning, Dr. Martha Burns, recently gave a webinar called “BrainPro: Preventing Summer Brain Drain.”
Dr. Burns covered a number of points related to learning and retaining information
Following Dr. Burns, we heard from Jenny, a parent from Florida who had her teenage daughter use the BrainPro program to help her pass the FCAT (the Florida Comprehensive Assessment Test). Her daughter has a very high GPA and takes AP and Honors classes, but had difficulty in passing the FCAT reading test two years in a row. After she went through the BrainPro program, she took the FCAT for the 3rd time and passed with a near perfect score on the test.
View the webinar to for more detail and visuals about how the brain learns, and find out how the BrainPro program can help learners stay sharp over the summer break.
We generally don’t consider the development of manual dexterity like hand-eye coordination in babies to be an essential element of cognitive development. In fact, the scientific terminology itself – “motor skills” for movement and “cognitive skills” for mental processing – draws a clear and definite separation between these two types of functions.
As it turns out, such thinking may be holding us back from innovations in education that might truly be able to make a difference for a great many young learners.
Recent research has demonstrated a clear connection between the development of fine motor skills in early life and later success in math, science and reading. Such skills – those as simple as how an infant can use her eyes to track her mother’s face and then reach her hand out and touch her mother’s nose – may just help us understand how ready that child will be for kindergarten, as well as what kind of achiever she’ll be over the next few years.
The Motor-Cognition Connection
To arrive at such a conclusion, we first need to understand the connection between the motor and cognitive centers of the brain. Through neuroimaging and neuroanatomical analysis, Adele Diamond (2000) uncovered “significant evidence” for a number of motor-cognition links in the brain. Prior to such analysis, these abilities were attributed to separate areas of the brain: motor skills were centered in the cerebellum and basal ganglia, and cognition in the prefrontal cortex. But Diamond’s research showed that both could be activated during certain motor or cognitive tasks. Further research also showed that “individuals with brain damage to either the primary motor or primary cognitive areas often show impairment in both skill areas.” (p. 1013)
In fact, Karen Adolph (2005, 2008; Adolph & Berger, 2006) suggested that a complex relationship exists between cognitive and motor skills development in infants. Since infants are learning to process a complex and changing world at the same time that they are learning gross and fine motor skills, they are in a state of constant adaptation. Their bodies are changing simultaneously as the world around them is presenting new information. Thus, their physical existence in the world – and their movement through it – is one that requires constant cognitive problem solving. In short, infants spend the vast majority of their existence, when they are not sleeping, learning how to learn.
Motor Skills as a Predictor
Talk about factors that predict future achievement in reading, math and science most often includes discussions of early math skills, early reading skills, social skills, attention skills, and attention-related measures like curiosity, interest and a desire to learn. Note that none of the aforementioned abilities has a motor physical component.
Yet, from the motor-cognition connection, researchers like David Grissmer, Sophie Aiyer, William Murrah, Kevin Grimm and Joel Steele (2010) have brought the issue of motor skills development to the fore. They went back and analyzed data from six data sets, and found that, indeed, fine motor skills were a strong predictor of later achievement. In fact, they conclude that taken together, “attention, fine motor skills and general knowledge are much stronger overall predictors of later math, reading and science scores than early math and reading scores alone.” (p. 1008)
Toward Better Interventions
According to this team of researchers (Grissimer, et al, 2010), “There are few interventions directly testing whether strengthening early attention, fine motor skills, or knowledge of the world would improve later math and reading achievement.” That said, some facts are quite clear:
Ultimately, with that understanding in hand, we clearly have a research opportunity to more comprehensively pursue an understanding of these connections. Findings from such research could put us in a position to create more novel, more effective interventions that strategically integrate motor and cognitive skill building, and continue to hone how we help our youngest learners prepare for future success.
For further reading:
Grissmer, D., Grimm, K., Aiyer S., Murrah, W., Steele, J. Fine Motor Skills and Early Comprehension of the World: Two New School Readiness Indicators. Developmental Psychology. 2010. Vol. 46, No. 5. 1008-1017.
Just about everyone has had the experience of going grocery shopping with a small list of purchases in their mind, only to forget one or more of them upon arriving at the store. Similarly, we all have left one room to retrieve something from another room, forgetting what we are after before we have even arrived. The ability to hold information in mind for a few minutes to a few hours is called working memory. It is essential for everything from language learning in children to following a book chapter from beginning to end.
Working memory was first defined by Alan Baddeley and Graham Hitch in 1974. It is a form of memory that may distinguish humans from many other animals (with the exception of several primates). Working memory, commonly referred to as short-term memory, allows a person to hold on to information for a period of time (minutes or perhaps hours) long enough to do something new with the information, like take notes or solve a problem.
A typical situation in which we rely on working memory is watching an informational program on television, like a segment on a news program, and discussing it later with a friend. We may forget about the specific news event later in the week, but for a period of time we “keep it in mind,” thinking about it and perhaps talking about it with others. Each time we share the information with another person or think about it ourselves, we select details that interest us and alter them slightly to keep them interesting to us. Other examples of tasks that require good working memory in adults include taking notes during a lecture or paraphrasing information we hear or read about.
Alan Baddeley elaborated on the original concept of working memory in 1992, noting that unlike other kinds of short-term memory (such as rote repetition), working memory requires us to focus and maintain our attention on the task at hand. To keep our attentional focus, we must be goal-directed, ignoring distractions that might interfere with goal attainment. Baddeley stressed the importance of the “central executive” system for maintaining attentional focus in working memory tasks.
For children, working memory is essential for learning language. Unlike vision, where we can often study an image as long as we need to, everything we hear occurs in time. The speech signal moves very quickly: an average sentence is about 14 seconds long, an average single syllable word lasts only a quarter of a second, and the average consonant sound may last only 1/12 of a second.
We are all made aware of how fleeting the speech signal is when someone is talking to us and we become distracted, which consequently requires us to ask the speaker to repeat what was just said. In that way, speech is like a billboard that appears briefly in our peripheral vision as we travel at 55 miles per hour along a highway. It we are not paying specific attention in that instant to that part of the road, we will miss it, or only retain small bits of the message on the billboard. In a similar way, information we hear leaves us as soon as it arrives. We are not able to hold it in view like a drawing or photograph, or study it like a person’s face, so we must keep the information in our mind.
For some, improving working memory can be as simple as getting more sleep or more exercise or learning to avoid distractions. For others, whose working memory is weak enough to significantly impact learning, more help may be needed. Fortunately, the brain is a malleable structure and cognitive skills like working memory can be improved by strengthening key learning pathways in the brain (as regular readers of this blog know—working memory is one of four cognitive skills rapidly strengthened by the Fast ForWord program).
The truth is, we live in an exciting time. Scientists are learning more all the time about how cognitive skills like working memory operate. We can look forward to these discoveries yielding more insights and tools that we’ll be able to use to optimize learning throughout our lives.
What is a parent to do to get a child’s brain started out on the right path – to be able to concentrate on one task for extended periods, be able to handle rapidly changing information, and be flexible enough to switch tasks easily?
Well, it turns out the human brain seems to have a strategy: by developing two core capacities during the first few years of life, interactive play and language, the brain seems to become uniquely equipped to build a range of cognitive capacities. Recent research suggests that a specific area in the frontal lobe – ‘the doing part of the brain’ - begins to wire itself very early in development through imitation of the movements and sounds made by others. This area, the so-called mirror neuron region, allows an infant to watch or listen to other people and respond with imitative or complementary movements or sounds.
Because this area is the same region, in the left hemisphere, that is responsible for fluent, easy articulated, speech, researchers have speculated that it might have been an evolutionary starting point for development of human language. But, because it is also active in the right hemisphere, it seems to play an important role in social, and perhaps athletic, interaction. In fact, Miella Dapretto and her colleagues at UCLA recently reported research showing that children with autism spectrum disorders, which include a range of disturbances that impact, among other things, social skill development, have observable deficiencies in the mirror neuron system.
There is reason to speculate, based on the research now available, that exercising the mirror system in general, can build a brain that is better equipped for socialization, school, music and athletics. At this time existing research has demonstrated that exercising Broca’s area of the brain (and other areas that are connected to this area through complex cognitive networks), either through natural parental stimulation in infants or through intense specific practice in school-aged children or adults, one can systematically build a brain that is better equipped for many cognitive tasks including language, reading, writing, and math as well as remediate a brain that seems to have deficits or learning disabilities in one or more of these areas.
Every time a parent plays a game like “Patty-cake, Patty-cake” where the child and parent duplicate a routine with actions and a poem or song, the parent is helping the child to exercise the mirror neuron system. Parents have been doing these action/nursery sequences for years, and there are many similar routines in many cultures. Examples of “mirror neuron” routines that have been around and passed on for generations in Western cultures include – “So Big!” where a parent ask the child something like, “How big are you?” and the child and parent respond together holding up their arms in like fashion, “SO BIG!” or, with older children, “Eensie Weensie Spider” where parent and child imitate each other by alternately touching the thumb of one hand to the forefinger of the other hand to emulate the spider climbing up a water spout.
The wonderful thing about these types of routines is that they illustrate how intuitive parents have been for centuries, at identifying and exploiting the natural directions and priorities of brain development. What worries many of us in neuroscience is when parents abandon these time-tested and intuitive interactions with our young children, swayed by technological advances that enhance productivity and drive positive cognitive changes in a mature brain but by abandoning natural parental interactive routines may actually jeopardize the delicate balance of stimulation in the developing brain.
We must exercise caution when adults develop products that appeal to parents with names that inspire confidence like, “Baby Einstein”, if the products have not been subjected to reasonable controlled studies that will help us understand the impact of these activities on young brains. Most companies that develop products for young children do not conduct this type of research because the assumption is that toys and play activities that engage infants and keep them entertained are not harmful. But, unfortunately, that assumption is not warranted. Many of us who put our children in “walkers” or “swings” in the latter part of the twentieth century learned that these “toys” had unintended consequences (i.e., negative effects, on early motor development).
As developmental neuroscientists and other specialists have begun to understand the implications, both positive and negative, of early stimulation on later brain development, those of us in the sciences need to better inform parents and “toy” makers may need to attempt more accountable to parents. In all fairness, however, it may be unreasonable to expect toy makers to conduct independent controlled research studies that we have not even demanded of drug companies. So, the view held by many scientists is that an educated parent can look beyond the hype of advertising and provide for the young child in their care, a fostering environment that is calmly yet convincingly brain-enhancing.
For Further Reading:
The Mirror Neuron System and the Consequences of Its Dysfunction. Marco Iacoboni and Mirella Depretto. Nature Reviews | Neuroscience Volume 7, December 2006
The Mirror Neuron System is More Active During Complementary Compared with Imitative Action. Roger Newman-Norlund, Hein T van Schie, Alexander M J van Zuijlen, and Harold Bekkering. Nature Neuroscience Vol. 10, May 2007
Using Human Brain Lesions to Infer Function: A Relic from a Past Era in the fMRI age? Chris Rorden and Hans-Otto Karnath. Nature Reviews | Neuroscience Vol. 5, October 2004
Understanding Emotions in Others: Mirror Neuron Dysfunction in Children with Autism Spectrum Disorders. Mirella Depretto, Mari S. Davies, Jennifer H. Pfeifer, Ashley A. Scott, Marian Sigman, Susan Y. Bookheimer, and Marco Iacoboni. Nature Neuroscience Vol. 9, December 2005
Social Intelligence: The New Science of Human Relationships. Daniel Goleman. NY, NY: Bantam Books, 2006.
Neural Plasticity: The Effects of Environment on the Development of the Cerebral Cortex (Perspectives in Cognitive Neuroscience). Peter R. Huttenlocher. Cambridge, MA: Harvard University Press, 2002
Neural Mechanisms of Selective Auditory Attention are Enhanced by Computerized Training: Electrophysiological Evidence from Language-Impaired and Typically Developing Children. Courtney Stevens, Jessica Fanning, Donna Coch, Lisa Sanders,and Helen Neville. Brain Research Vol. 1205, April 2008.
For most of us, interpreting and expressing emotion is something deeply instinctive. But what happens when that ability to express ourselves or read another’s emotions goes awry? Imagine what can happen to a student’s classroom experience if they can’t make sense of something as simple as their teacher’s facial expression. In the past, these kinds of students have been seen as having behavior problems. So how can we help them succeed?
Research has shown that people with traumatic brain injuries often experience this same inability to interpret and respond to emotions, a condition called "affect recognition."
Barry Willer, professor of psychiatry and specialist in TBI (traumatic brain injury) of the University of Buffalo, tells the story of a man and his wife who came into his office with a problem. The woman had experienced a mild traumatic brain injury. While her husband was supporting her recovery as best he could, she consistently described his attitude as “indifferent. “ He was frustrated, to say the least.
“His wife didn’t know she wasn’t recognizing his emotions,” said Willer, recounting the story in a 2009 interview with Insciences Journal , “and he had no idea what was going on.”
This couple is by no means alone. Nearly fifty percent of all traumatic brain injuries result in problems interpreting and expressing emotion.
As educators, being able to connect with our students at an emotional level is essential to classroom success. Without that connection, the learning process can quite easily come to a halt. Thankfully, Willer has demonstrated that there is hope for this population, and that the human brain is quite capable of re-learning how to understand facial expressions and use that information to interpret emotion.
Willer and his team have developed two specific interventions that have shown positive results:
"What was so exciting about our preliminary study," says Willer, "is that someone may lose the ability to recognize emotions, but even 10 years later, they can re–learn the skill if given the right assistance."
As it turns out, the only emotion that traumatic brain injuries do not erase is "happy," which is very hard–wired and has an extensive amount of "redundant circuitry." Says Willer, "I don’t know how that happened, but we all can be glad it did."
For further reading: Milders, M., Fuchs, S., & Crawford, J. R. Neuropsychological impairments and changes in emotional and social behaviour following severe traumatic brain injury. Journal of Clinical and Experimental Neuropsychology, 25, 2003. 157-172.
Earlier this year, I wrote about a researcher named Dr. Miguel Nicolelis at Duke University Medical Center and his work with a monkey named Aurora. Through placing implants in Aurora’s skull, Nicolelis was able to record Aurora’s motor nerve signals as she used a joystick to play a simple video game. He then used a computer algorithm to convert those signals into code to power a robotic arm. Over time, because of her brain’s ability to adapt and learn, Aurora taught herself how to control the movements of that robotic arm by just thinking about it.
What we see in Nicolelis’s work is the complex interplay of three different elements of a neural prosthetic system: hardware, software, and what has been come to be known as “wetware.”
Through choreographing the delicate dance between these three systemic elements, biomedical professionals are becoming more able to develop neural prosthetics that continue to improve the quality of life for any number of disabilities, substituting motor, sensory or cognitive capabilities that have been damaged as a result of injury or disease.
Today, biomedical research has given rise to any number of neural prostheses. Visual prosthetics stimulate the optic nerve to counter certain types of blindness. Spinal cord stimulators induce sensations to mask and control pain. Pacemakers work with the muscle and nerves of the heart to monitor and regulate the heartbeat and control fibrillation.
One of the most common applications of the neural prosthesis concept is in the cochlear implant. Dr. Michael Merzenich, professor emeritus and neuroscientist, was the Principal Investigator back during the development of the first cochlear implants at the University of California, San Francisco. The work showed that in as little as six months, patients were able to develop remarkable speech discrimination abilities. It was found that speech discrimination abilities improved over time due to the brain’s plastic ability to change and adapt to these new inputs.
According to the NIH’s National Institute on Deafness and Other Communications Disorders, over 59,000 adults and children have cochlear implants. Just like Aurora’s robotic arm, a cochlear implant involves the integration of hardware, software and wetware. But instead of using motor neurons to articulate robotic fingers, cochlear implants form the technological bridge between the world of sound and the ability to perceive that sound in someone whose ears cannot convert sound vibrations to a nerve impulse. While the ones we developed had a single channel, today’s devices have up to 120, which allows for better input fidelity through stimulating different parts of the auditory nerve.
Of the three elements of the neural prosthetic system, hardware, software and wetware, the only one of them that can be expected – even depended upon – to change over time is the wetware. Both because of normal development and brain plasticity, an individual’s ability to effectively use neural prosthetic will naturally change over time as the individual’s own nervous system adapts to make better use of the hardware and software.
As Dr. Nicolelis demonstrated with Aurora, wetware is an amazingly malleable apparatus. We might imagine these neural prosthetic systems as fantastically complex in terms of their hardware and software. That said, research out of the University of Washington, Seattle, has suggested that, because of brain plasticity, we may be able to use simpler algorithms in the external hardware and software, and depend upon the plasticity of the wetware to make optimal use of these devices.
In the end, we as humans, with our drive to heal and discover, seem to have a limitless ability to develop innovations to remedy our physical ills. And yet, it is the plasticity of our nervous system’s innate ability to adapt that will apparently allow us to make the most of these innovations.
For further reading:
Fallon, J. B., Irvine, D. Shepherd, R. Neural Prostheses and Brain Plasticity. J Neural Eng. 2009 December.
Moritz, C. T., Perlmutter, S. I., Ftez, E. E. Direct Control of Paralysed Muscles by Cortical Neurons. Nature. 2008 December.
The brain is one of the most mysterious and misunderstood organs in the body. It represents the seat of our judgment, our senses, perceptions and our creativity. More than any other aspect of our anatomy, the uniqueness of our brains is at the core of what makes us truly human.
While neuroscience advances every day, there are a number of myths about the brain that are accepted by many people as fact. As a scientist, I and my colleagues have worked to uncover the brain’s truths. So what are some of these myths – and what are the true stories behind them to the best of our scientific knowledge?
Fiction: We use only a small percentage of our brains.
Fact: General thinking is that we use only about 10% of our brains. Nothing could be further from the truth. Brain scans such as MRI and PET scans show that we regularly use all parts of our brains. Certainly, different areas of the brain are activated during different types of tasks, and some parts of the brain are less critical to support vital functions than others. But as even small brain injuries can show, every part of the brain performs essential functions in how we process, communicate with, and move through the world around us. Read more at http://www.scientificamerican.com/article.cfm?id=do-we-really-use-only-10.
Fiction: The wrinkles on the surface of the brain appear and become more pronounced as we learn.
Fact: The ridges and crannies – more correctly, the gyri and sulci – on the surface of the brain actually all appear by the time a fetus is 40 weeks old. As the human brain evolved, gyri and sulci appeared as a result of the brain having to fold in upon itself as it grew larger to fit inside a correctly proportioned skull. While the gyri and sulci do not change as we learn, the brain itself – as we know from research in brain plasticity -- does continue to change throughout our lives.
Fiction: Brain damage is permanent.
This is an interesting myth, in that it is the result of ambiguous language. The brain is made up of a collection of neurons – brain cells – that are all networked together. When the brain suffers trauma and neurons are destroyed or damaged, those neurons cannot regenerate. In that sense, the damage to them is permanent. That said, those neurons are linked together at synapses to form complete networks. While a single neuron cannot be repaired, the pathways and connections throughout the brain can rewire themselves and form new pathways. If a connection is lost due to injury, we can reestablish that connection if the damage is not so acute that the entire network cannot be rewired. For a scholarly treatment of how the brain recovers from injury, see http://web.uvic.ca/~skelton/Teaching/General%20Readings/Robertson%20Murre%201999.pdf.
Fiction: A person is either “left-brained” or “right-brained.”
The theory goes that left-brained people are more logical and right-brained people are more creative. Certainly there are asymmetries associated with locations of certain brain functions. For example, mathematical computation and the grammar and vocabulary aspects of language seem to be controlled in most people in the left brain, while numerical approximation and comparison, along with interpretive aspects of language like prosody and intonation, appear to be controlled in the right. These ideas date back to original research done in 1861 by French physician Pierre Paul Broca. Today, through MRI and PET imaging techniques, we have a much more complex view of the way the brain’s hemispheres control functions and interact with one another. The two perform a complex dance of information exchange that gives rise to our abilities. For a look at results of some of these MRI tests in children, see http://www.ncbi.nlm.nih.gov/pubmed/8780075.
Fiction: There are five senses: sight, smell, hearing, taste and touch.
These five are simply the ones that we are most aware of in our conscious minds, but we perceive and sense the world in a great many other ways. For example, “proprioconception” describes how our bodies are oriented in the world. “Nociception” is how we perceive pain. We sense changes in temperature. We sense balance. We feel thirst and hunger. We sense the passage of time. For a quick and easy description of the senses – in humans as well as other species – see http://en.wikipedia.org/wiki/Sense.
As scientists continue our search for the facts, there is much we don’t know; we are expanding our knowledge of the brain’s truths every day. As new discoveries are made, it is natural for facts to become distorted and reinterpreted with each new telling. As educators and scientists, we should take the time to explain the truths about the brain and rectify any misunderstandings we may hear others repeat. The brain is amazing, and communicating the truths about it will further society’s understanding as a whole.