How Brains Learn To See


Pawan Sinha details his groundbreaking research into how the brain’s visual system develops. Sinha and his team provide free vision-restoring treatment to children born blind, and then study how their brains learn to interpret visual data. The work offers insights into neuroscience, engineering and even autism.

Weekly Neuroscience Update

FASD impacts brain development throughout childhood and adolescence not just at birth

Highlighted areas are some of the white matter tracts the research group studied. Credit: U of A

Medical researchers at the University of Alberta recently published findings showing that brain development is delayed throughout childhood and adolescence for people born with Fetal Alcohol Spectrum Disorder (FASD).

Whenever we have to acquire new knowledge under stress, the brain deploys unconscious rather than conscious learning processes. Neuroscientists at the Ruhr-Universität Bochum have discovered that this switch from conscious to unconscious learning systems is triggered by the intact function of mineralocorticoid receptors.

Researchers have reverse-engineered the outlines of a disrupted prenatal gene network in schizophrenia, by tracing spontaneous mutations to where and when they likely cause damage in the brain. Some people with the brain disorder may suffer from impaired birth of new neurons, or neurogenesis, in the front of their brain during prenatal development, suggests the study.

Autism is marked by several core features — impairments in social functioning, difficulty communicating, and a restriction of interests. Though researchers have attempted to pinpoint factors that might account for all three of these characteristics, the underlying causes are still unclear. Now, a new study suggests that two key attentional abilities — moving attention fluidly and orienting to social information — can be checked off the list, as neither seems to account for the diversity of symptoms we find in people with autism.

Anemia, or low levels of red blood cells, may increase the risk of dementia, according to a study published in the July 31, 2013, online issue of Neurology, the medical journal of the American Academy of Neurology

Physicists and neuroscientists from The University of Nottingham and University of Birmingham have unlocked one of the mysteries of the human brain, thanks to new research using Functional Magnetic Resonance Imaging (fMRI) and electroencephalography (EEG). The work will enable neuroscientists to map a kind of brain function that up to now could not be studied, allowing a more accurate exploration of how both healthy and diseased brains work.

Death Of Broadcasting Legend Colm Murray

Colm Murray

Colm Murray

I am saddened to hear of the death last night of  the hugely popular RTÉ Sport broadcaster Colm Murray,  who was diagnosed with motor neurone disease three years ago.

In a moving documentary MND – The Inside Track, aired last year on RTE television, the broadcaster said that he wanted to do something “positive”, despite his personal struggle. His doctor, Trinity and Beaumont Professor Orla Hardiman, hailed him for his willingness “to be of service”, and to help find a future cure by partaking in medical trials. “Colm could easily have laid down to the disease and become a victim but he instead became a champion,” she said.

While he admitted at the time that he did not expect to be cured, Colm Murray said that it was his most “fervent wish that the coming years will see giant steps forward in the battle to find a cure”.

“It gives me something to hope for. It’s a faint glimmer of light at the end of a very dark tunnel.”

What is Motor Neurone Disease?

One in 50,000 people will develop the terminal disease, which attacks the central nervous system, and ultimately destroys all muscular function, but what exactly is this disease?

Amyotrophic Lateral Sclerosis (ALS)*,  also known as Motor Neuron Disease,  targets the nerves controlling the muscles of movement including postural muscles eventually disabling those nerves controlling chest breathing. Interestingly nerves regulating the senses, seeing, hearing, touching, tasting and smelling are not affected. Cognition is not affected – dementia is rare.

Incidence

ALS occurs in 2-5 people per 100,000 with slightly more males affected than females. The origin is still a mystery however elite sportsmen and women are disproportionally affected.

The podcast below gives an excellent in-dept explanation of ALS.

http://neuroscene.com/?p=204

*Amyotrophic Lateral Sclerosis 

A = lack of:   Myo = muscle; Trophic = nourishment;

Lateral = location in the spinal cord;   Sclerosis = scarring.

Neural Simulations Hint at the Origin of Brain Waves

For almost a century, scientists have been studying brain waves to learn about mental health and the way we think. Yet the way billions of interconnected neurons work together to produce brain waves remains unknown. Now, scientists from EPFL’s Blue Brain Project in Switzerland, at the core of the European Human Brain Project, and the Allen Institute for Brain Science in the United States, show in the July 24th edition of the journal Neuron how a complex computer model is providing a new tool to solve the mystery.

Weekly Neuroscience Update

A novel screening method makes it easier to diagnose and treat children with autism

A child with autism discovers how to evoke the onscreen video he likes best. Credit: Rutgers Sensory-Motor Integration Lab

Researchers have developed a new screening method to diagnose autism, which unlike current methods does not rely on subjective criteria. These results are published in a series of studies in the open-access journal Frontiers in Neuroscience.

Going to bed at different times every night throughout early childhood seems to curb children’s brain power, according to a large, long term study.

A computational vision scientist at the University of South Australia has just published new research describing a key advance in our understanding of how the brain perceives the physical world.

Oxytocin has long been known as the warm, fuzzy hormone that promotes feelings of love, social bonding and well-being. It’s even being tested as an anti-anxiety drug. But new research shows oxytocin also can cause emotional pain, an entirely new, darker identity for the hormone.

Ultrasound waves sent to specific brain regions can alter a person’s mood, according to a new study published in the journal Brain Stimulation.

A gene related to neural tube defects in dogs has for the first time been identified by researchers.

UCLA chemists and molecular biologists have for the first time used a “structure-based” approach to drug design to identify compounds with the potential to delay or treat Alzheimer’s disease, and possibly Parkinson’s, Lou Gehrig’s disease and other degenerative disorders.

BrainGate : Thought Control Of Robotic Arms

A trial is evaluating an investigational device called the BrainGate neural interface system. This is a type of brain-computer interface (BCI) intended to put robotics and other assistive technology under the brain’s control. By imagining the movement of their own arms, two paralyzed individuals were able to use the BrainGate to make complex reach-and-grasp movements with robotic arms.

Weekly Neuroscience Update

sad music

Sad music might actually evoke positive emotions reveals a new study by Japanese researchers. The findings help to explain why people enjoy listening to sad music, say Ai Kawakami and colleagues from Tokyo University of the Arts and the RIKEN Brain Science Institute, Japan.

Extroverts may be more outgoing and cheerful in part because of their brain chemistry, reports a study by Cornell neuroscientists.

Researchers at Neuroscience Research Australia (NeuRA) have discovered that the region of the brain called the orbitofrontal cortex plays a key role in linking emotion and memories. The finding comes from a new study, which demonstrates that patients with frontotemporal dementia (FTD) lose the “emotional content” of their memories.

Researchers in Oxford have demonstrated a significant improvement in the treatment of advanced Parkinson’s disease with deep brain stimulation.

In a study examining how bilingual children learn the two different sound systems of languages they are acquiring simultaneously, researchers have discovered insights that indicate children can learn two native languages as easily as they can learn one.

Scientists have developed a method with which the chances of success of a surgical procedure for temporal lobe epilepsy can be accurately predicted.

How Did Tolerance Kill Cory Monteith?

Corey M

I was saddened this week to read of the coroner’s verdict on the death of Cory Monteith.  The 31-year-old talented actor and performer had been plagued by substance abuse problems long before his Hollywood days and had voluntarily checked himself into rehab in March where he completed a 30-day program.

Heroin and alcohol – a potentially lethal mix

Over the past two decades I have visited high schools and colleges to talk on how addictive drugs including heroin and alcohol affect the brain and it still amazes me how little the general public understand how these potentially lethal drugs work.

The post mortem showed the Cory’s death was due to a combination of heroin and alcohol intake. Both heroin and alcohol have similar effects on the brain. They both elevate mood, lower heart rate and put your brain into a sleepy inattentive state.  Heroin and alcohol are what’s called narcotics (i.e. sleep inducers) and sometimes called nervous system depressants – not to be confused with a depressed mood but relating as to how these drugs act to silence (i.e. depress) activity in the nervous system.  It is no coincidence then that a street name for heroin is dope. Once in the brain, heroin is converted to morphine by enzymes and the morphine binds to opiate receptors in certain areas of the brain. Alcohol in contrast, acts in a less specific way by making neurons ‘leaky’.  Both drugs are highly addictive and to make matters worse, at high enough doses they  both can act as anaesthetics – drugs that switch off important nervous functions in the brain stem – like for instance, respiration (breathing) and it was the combined effect of both of these drugs  in slowing and eventually stopping breathing which was why Cory died.

Many addiction experts were not surprised

It is clear from reading newspaper reports that although Cory Monteith’s friends and loved ones are deeply shocked by the revelations of the inquest many addiction experts were not surprised.  Corey struggled with drugs since he was 13 – so long in fact that his chronic addiction was hardwired into his brain. Thus, 30 days in rehab was not enough time to get to the root cause of the addiction especially if there were any underlying psychiatric issues. Brain rewiring for chronic addiction usually takes between 90 and 120 days to be effective.  Alarm bells should also have rung after he was released from rehab when he went on vacation to Mexico.  A vacation was a huge post-rehab mistake as a structured, supportive environment is so important to grow, maintain and strengthen the new brain connections.

What is tolerance and how did it kill Cory?

Not everyone who takes heroin and alcohol together dies; so what is so special about Cory’s situation? Cory died because of a brain phenomenon called tolerance. When drugs such as heroin are used repeatedly over time, tolerance may develop.  Tolerance occurs when the person no longer responds to the drug in the way that person initially responded.  Stated another way, it takes a higher dose of the drug to achieve the same level of response achieved initially.  So for example, in the case of heroin, morphine and alcohol tolerance develops rapidly to the effects of the drug.  The development of tolerance is not addiction, although many drugs that produce tolerance also have addictive potential.  Tolerance to drugs can be produced by several different mechanisms, but in the case of heroin, morphine and alcohol tolerance develops at the level of biochemical reactions mainly within the liver whereby  enzymes adapt so that the drug can no longer cause changes in brain cell firing. Thus, the effect of a given dose of heroin, morphine and/or alcohol is diminished.

A decrease in tolerance after rehab put Cory’s brain at risk

During the 30 days in rehab Cory’s body gradually rid itself of drugs and tolerance also gradually faded. The reasons why Cory’s death occurred shortly after his release from rehab was because of a large decrease in tolerance that his body experienced after that period of abstinence. Thus, when Cory returned to using, he ran the risk of experiencing a far more extreme reaction to the same drug doses that he was once accustomed to using.

It is particularly sad that our memories of this genuinely loved and popular person may be tarnished by the revelation. I would urge people not to let this be the case, and to remember Corey for his talent and not the sordid nature of his death.

Drug taking as a way of coping

I do think however that Cory’s death might not be in vain if it opens up a debate on how we as a society deal with stress. We have heard that Cory had a history of chronic addiction and we are led to surmise that alcohol and drug taking was his way of coping. In this he is not alone. As the world economy continues on its downward slide, and unemployment and financial worries beset us, are we going to turn more and more to these quick fixes to handle our dis-stress?

Probably the most important lesson to be taken from Cory’s death is the realization that the stresses of life and how we manage them IS the difference between life and death. I look forward to developing this theme in greater detail including drug-free tips on how the avoid worry and stress in future posts, but in the meantime, my deepest sympathy goes to Cory’s loved ones at this difficult time.

The Brain Science Of Learning (Podcast)

orbitEarlier this year I was interviewed by Radio Adelaide’s Ewart Shaw, host of the weekly ORBIT – the ideas in education radio show on what we already know about the learning process in the brain.

During the course of the interview I discussed recent scientific findings linking education with neuroscience around the emerging field of neuroeducation, including the educational relevance of factors such as exercise, motivation and stress and how they are informing the teaching/learning process in the classroom.

You can download a podcast of the interview from this link.