Saturday 22 October 2011

How do Babies Learn?

So which is it? Are babies mindless beings who only eat, sleep and cry? Or are they little geniuses, ready for academic pursuits? The truth is probably half way between the two. There is no doubt that the brain of a baby is like a sponge which eagerly soaks up information and that brain plasticity in young babies is at it's peak. What we must also realise however is that young babies need a secure, loving environment in order to utilise this inherent neuroplasticity.

In evolutionary terms, babies have not changed a great deal over the last 50,000 years. However, what we know about them has changed a great deal.

Astute observers of human development have always believed that the early years were critical to developing potential and this view is supported by evidence that children exposed to highly enriched environments develop bigger, superior brains, whilst children who are exposed to impoverished environments have smaller, less well developed brains. This is a view which began as early as the Greek philosopher Aristotle and was developed in the 11th century by the Persian philosopher, Ibn Sina (known as "Avicenna" in the West. He argued that the "human intellect at birth is rather like a tabula rasa, a pure potentiality that is actualised through education and experience of the world and consequently ' “comes to know" '

While this information is exciting and hopeful, especially to the parents of children whose development has been adversely affected by brain injury or some ather retarding factor, it also poses a danger, as some professionals and parents think it means we should apply intensive and exhaustive programmes of stimulation to teaching both brain injured and 'well' children in order to maximise their potential. Enter the billion-dollar baby industrial complex to sell us videos and flash cards to make our babies "smarter and the clinics offering eight to ten hour day – long programmes of developmental stimulation to children with developmental problems.

But a number of researchers have found clear evidence that some promotion of early learning tasks can actually interfere with later learning. Not only that, but that ensuring that the child has plenty of 'downtime' actually improves the learning process. This recent study by Ellenbogen et al demonstrates that relational memory -- the ability to make logical "big picture" inferences from disparate pieces of information, and an essential part of learning - is dependent on taking plenty of breaks and even more important, getting a good night's sleep. I believe that this is where other rehabilitation centres have it worng and where Snowdrop have it right in relation to the programmes of developmental stimulation we provide for brain injured children.

So here's the dilemma: We know we're supposed to be doing something to take advantage of the early years of brain development, but what? The answers to this query may be simpler than we think. They require only the simplest understanding of how babies operate.

First, babies are wired for relationships. To paraphrase the great Russian psychologist Lev Vygotsky, everything children need to know comes to them through relationships which provide interaction with more skilled partners, relationships that mean something to them personally. From birth, they use their emerging skills to seek out those they can learn to trust. They flourish when they know they are secure. They fall apart and under-perform when they are stressed. Their behaviour is organised and meaningful. They communicate clearly when stressed if we will but pay attention to their cues. When their needs are met, they snuggle, coo and sleep. When they feel overwhelmed, they fuss, turn red and lose motor coordination.

So babies need to be cared for by their parents and grandparents and other caregivers in a way that "listens" to what they tell us with their behaviour. Responsive care-giving gives children evidence that their needs matter. It teaches them to respect themselves and others.

They need to be cared for by people who are emotionally available to them. They need to see a smile reflect their own and a look of concern in someone's face when they cry. When they make attempts at language, they need to be heard and responded to by someone who really wants to know what they have to say. They need opportunities to play with other children and figure out what works in human interaction. They need some freedom to choose their own play activities and interact with others in their own comfortable style.

When children are confident in their safety and acceptance, they can relax and learn. According to Bjorklund and other evolutionary psychologists, learning is inhibited by fear and anxiety but facilitated by security and the opportunity to choose. Children are born learning as a natural response to their interesting world. They only need our interest and support. We adults serve as guides to help them find their way.

Anyone wanting more information on Snowdrop's work should email info@snowdrop.cc, or go to our website at http://www.snowdrop.cc

Friday 21 October 2011

The Brains of People with Autism Develop More Slowly.

Yet again we see that some types of autism are clearly linked to the development of abnormal wiring patterns in the brain.  We know that the wiring pattern is largely determined by two factors, - either genetic expression, or when brain injury forces the brain to alter the normal wiring pattern.  What we also know is that environmental stimulation is the most powerful influence on that wiring pattern, which is why Snowdrop provides programmes of neurodevelopmental stimulation, which increases the normal environmental stimulus in order to try to influence the brain not to adopt an abnormal wiring pattern.

With thanks from the University of Claifornia.
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Researchers at UCLA have found a possible explanation for why autistic children act and think differently than their peers. For the first time, they’ve shown that the connections between brain regions that are important for language and social skills grow much more slowly in boys with autism than in non-autistic children.
Reporting in the current on-line edition of the journal Human Brain Mapping, senior author Jennifer G. Levitt, a professor of psychiatry at the Semel Institute for Neuroscience and Human Behaviour at UCLA; first author Xua Hua, a UCLA post-doctoral researcher; and colleagues found aberrant growth rates in areas of the brain implicated in the social impairment, communication deficits and repetitive behaviours that characterize autism.
Autism is thought to affect one in 110 children in the U.S., and many experts believe the numbers are growing. Despite its prevalence, little is known about the disorder, and no cure has been discovered.
Normally, as children grow into teenagers, the brain undergoes major changes. This highly dynamic process depends on the creation of new connections, called white matter, and the elimination, or “pruning,” of unused brain cells, called gray matter. As a result, our brains work out the ideal and most efficient ways to understand and respond to the world around us.
Although most children with autism are diagnosed before they are 3 years old, this new study suggests that delays in brain development continue into adolescence.
“Because the brain of a child with autism develops more slowly during this critical period of life, these children may have an especially difficult time struggling to establish personal identity, develop social interactions and refine emotional skills,” Hua said. “This new knowledge may help to explain some of the symptoms of autism and could improve future treatment options.”
The researchers used a type of brain-imaging scan called a T1-weighted MRI, which can map structural changes during brain development. To study how the brains of boys with autism changed over time, they scanned 13 boys diagnosed with autism and a control group of seven non-autistic boys on two separate occasions. The boys ranged in age from 6 to 14 at the time of the first scan; on average, they were scanned again approximately three years later.
By scanning the boys twice, the scientists were able to create a detailed picture of how the brain changes during this critical period of development.
Besides seeing that the white-matter connections between those brain regions that are important for language and social skills were growing much slower in the boys with autism, they found a second anomaly: In two areas of the brain — the putamen, which is involved in learning, and the anterior cingulate, which helps regulate both cognitive and emotional processing — unused cells were not properly pruned away.
“Together, this creates unusual brain circuits, with cells that are overly connected to their close neighbours and under-connected to important cells further away, making it difficult for the brain to process information in a normal way,” Hua said.
“The brain regions where growth rates were found to be the most altered were associated with the problems autistic children most often struggle with — social impairment, communication deficits and repetitive behaviour,” she added.
Future studies using alternative neuroscience techniques should attempt to identify the source of this white-matter impairment, the researchers said.
“This study provides a new understanding of how the brains of children with autism are growing and developing in a unique way,” Levitt said. “Brain imaging could be used to determine if treatments are successful at addressing the biological difference. The delayed brain growth in autism may also suggest a different approach for educational intervention in adolescent and adult patients, since we now know their brains are wired differently to perceive information.”

Wednesday 19 October 2011

UCLA Study Demonstrates the Brain's Ability to Reorganise.


Thanks to 'Scienceblog' for this report, which again clearly demonstrates just how plastic the brain actually is. It is this inherent plasticity that Snowdrop aims to direct in our programmes of rehabilitation for brain injured children.

Visually impaired people appear to be fearless, navigating busy sidewalks and crosswalks, safely finding their way using nothing more than a cane as a guide. The reason they can do this, researchers suggest, is that in at least some circumstances, blindness can heighten other senses, helping individuals adapt.

Now scientists from the UCLA Department of Neurology have confirmed that blindness causes structural changes in the brain, indicating that the brain may reorganize itself functionally in order to adapt to a loss in sensory input.

Reporting in the January issue of the journal NeuroImage (currently online), Natasha Leporé, a postgraduate researcher at UCLA's Laboratory of Neuro Imaging, and colleagues found that visual regions of the brain were smaller in volume in blind individuals than in sighted ones. However, for non-visual areas, the trend was reversed -- they grew larger in the blind. This, the researchers say, suggests that the brains of blind individuals are compensating for the reduced volume in areas normally devoted to vision.

"This study shows the exceptional plasticity of the brain and its ability to reorganize itself after a major input -- in this case, vision -- is lost," said Leporé. "In other words, it appears the brain will attempt to compensate for the fact that a person can no longer see, and this is particularly true for those who are blind since early infancy, a developmental period in which the brain is much more plastic and modifiable than it is in adulthood."

Researchers used an extremely sensitive type of brain imaging called tensor-based morphometry, which can detect very subtle changes in brain volume, to examine the brains of three different groups: those who lost their sight before the age of 5; those who lost their sight after 14; and a control group of sighted individuals. Comparing the two groups of blind individuals, the researchers found that loss and gain of brain matter depended heavily on when the blindness occurred.

Only the early-blind group differed significantly from the control group in an area of the brain's corpus callosum that aids in the transmission of visual information between the two hemispheres of the brain. The researchers suggest this may be because of the reduced amount of myelination in the absence of visual input. Myelin, the fatty sheaf that surrounds nerves and allows for fast communication, develops rapidly in the very young. When the onset of blindness occurs in adolescence or later, the growth of myelin is already relatively complete, so the structure of the corpus callosum may not be strongly influenced by the loss of visual input.

In both blind groups, however, the researchers found significant enlargement in areas of the brain not responsible for vision. For example, the frontal lobes, which are involved with, among other things, working memory, were found to be abnormally enlarged, perhaps offering an anatomical foundation for some of blind individuals' enhanced skills.

Previous studies have found that when walking down a corridor with windows, the blind are adept at detecting the windows' presence because they can feel subtle changes in temperature and distinguish between the auditory echoes caused by walls and windows.

Leporé noted that scientists and others have long been curious about whether or not blind individuals compensated for their lack of vision by developing greater abilities in their remaining senses. For example, the 18th-century French philosopher Denis Diderot wrote of his amazement with some of the abilities shown by blind individuals, in particular a blind mathematician who could distinguish real from fake coins just by touching them.

But it wasn't until the early 1990s that the suspicions of science began to be confirmed with the development of neuroimaging tools.

"That allowed researchers to probe inside the brain in a non-invasive manner, yielding insights into the impressive adaptive capacity of the brain to reorganize itself following injury or sensory deprivation," Leporé said.

Other authors included Caroline Brun, Yi-Yu Chou, Agatha D. Lee, Sarah K. Madsen, Arthur W. Toga and Paul M. Thompson, all of UCLA, and Franco Leporé, Madeleine Fortin, Frédéric Gougoux, Maryse Lassonde and Patrice Voss, of the University of Montreal.

This study was supported by the Canadian Institutes of Health Research, the Canada Research Chairs Program, the National Institute on Aging, the National Library of Medicine, the National Institute of Biomedical Imaging and Bioengineering, the National Center for Research Resources, the National Institute for Child Health and Development, and a grant from the National Institutes of Health.
The researchers report no conflicts of interest.

The UCLA Laboratory of Neuro Imaging, which seeks to improve understanding of the brain in health and disease, is a leader in the development of advanced computational algorithms and scientific approaches for the comprehensive and quantitative mapping of brain structure and function. The laboratory is part of the UCLA Department of Neurology, which encompasses more than a dozen research, clinical and teaching programs. The department has ranked No. 1 among its peers nationwide in National Institutes of Health funding for the last seven years

Sunday 9 October 2011

Deficits in the reward system of the brains of children with ADHD found.

This is a very interesting study, with one elementary mistake! It was thought for years that the dopaminergic system was responsible for reward, - it isn't, but people, including scientists who should know better keep calling it so! The mesocorticolimbic system, which is a primary dopamine pathway, involving the stratium and the accumbens produces dopamine, but that dopamine does not produce 'reward' it produces 'desire' or what we would term 'craving.' - This 'desire' is the basis of addiction. What happens when this pathway is stimulated is that associated systems which produce opioids, - the brain's own heroin, are triggered to release those opioids, which is where the 'reward' comes in. However after a while, opioid production begins to fall and so we have desire without pleasure or reward! This is why addicts need more and more of a drug to feel the reward - to release the opioids! It is also why many addicts feel the craving to take drugs, but don't get pleasure from it! Anyway, it seems that this system might be undersensitive in some children who have ADHD and this research might lead to more effective treatments.   Indeed at Snowdrop, we use several techniques with children who have ADHD, which directly target these neural systems.

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The underlying causes of Attention Deficit Hyperactivity Disorder (ADHD) have yet to be well characterized. But a new study utilizing brain imaging has found an abnormality in the pathway responsible for the motivation/reward system in patients with ADHD. The finding may lead to more effective treatments for the condition as well as a greater understanding of ADHD behavior.

A hallmark of ADHD is lack of attention. Especially seen in the classroom, both children and adults with the disorder lack the ability to focus for extended periods of time. Scientists suspected the symptom was due to a deficit in motivation and reward system--a process which can hone focus with the understanding that a reward (or at least not a punishment) will be given if successful.

Studying that pathway is a difficult task. It relies on the chemical dopamine, which can be easily affected by ADHD treatment or drug abuse which is common in adult ADHD sufferers. Tests to this point have been relatively small, but a push by lead author Nora Volkow, Director of the National Institute on Drug Abuse, finally saw a sizable cohort of participants investigated.

53 adults with ADHD who had never received treatment were subjected to a PET scan along with 44 healthy controls. Researchers looked at both ends of the dopamine pathway--"dopamine receptors, to which the chemical messenger binds to propagate the "reward" signal, and dopamine transporters, which take up and recycle excess dopamine after the signal is sent."

The study showed those with ADHD had lower levels of both receptors and transporters. This was especially clear in the acumbens and midbrain, both of which are regions important to the motivation/reward process.

Understanding the deficit in dopamine can help change the way ADHD patients interact with the world. Volkow stated, "[The pathway's] involvement in ADHD supports the use of interventions to enhance the appeal and relevance of school and work tasks to improve performance."

Though the dopamine problems have not been a solid fact until this moment, the medication that has been used for decades were on the right track. "Our results also support the continued use of stimulant medications — the most common pharmacological treatment for ADHD — which have been shown to increase attention to cognitive tasks by elevating brain dopamine," Volkow said.

The team also hopes that this study will help adults with ADHD who tend towards drug abuse and obesity. The lack of dopamine makes the rewards system difficult to trigger, so overeating and over use of stimulant drugs may be seen as a dangerous form of compensation, an unconscious move to help bolster the feeling of reward. Developing therapies that help attenuate the need for drugs and binge eating will greatly improve quality of life. Thanks to the examiner