Teenage Brains

 Blame my brain: the amazing teenage brain by Nicola Morgan. Walker Books, 2013.

The human brain contains about 100 billion nerve cells (neurons). Each neuron has a long tail-like part (axon) and many branches (dendrites). A neuron sends super-fast messages to other neurons by passing a tiny electrical current along its axon and across very tiny gaps (synapses) into the dendrites of other neurons. Every single thing you do - thought, action, sneeze, emotion - happens when the neurons send the right messages, very fast, through the complicated web of branches.

Every time you repeat an action, or thought, or recall the same memory, that same web is activated and the web of connections becomes stronger, and the better you are at that specific task. But if you don't use those connections again, they may die off and you forget a fact or a name, or how to do something. To relearn something, you need to rebuild the web of connections by practicing again. If someone has a brain injury (e.g. a stroke) they might need to relearn how to walk or speak.

At birth a human baby has almost all of its neurons but few dendrites and therefore few synapses connecting them - so can't do very much. But their brains develop fast with new dendrites and synapses, as they learn to recognise people, talk and walk. There are also critical periods in brain development. If you don't learn a foreign language before the age of about seven, you can still learn to speak it fluently but probably always speak with the wrong accent, having passed the age when the brain can pick up accents. But most skills can be picked up at any age.

One type of neuron is called a mirror neuron. These neurons fire up when we watch someone else do something. If we watch several times, it may be easier for us to do the same thing because we have watched someone else do it. And it might be these neurons that help us feel what other people are feeling (empathy).

It was thought that all important development takes place in the first three years of life, but now we know that: (1) We can grow more neurons after we are born. (2) The brain grows and develops even into later life. (3) While some neurons die, we sometimes grow new ones. Adolescence is a time of major change in the volume of grey matter in the brain, and some parts of the brain are affected more than others. Not all teenagers show this in their behaviour, but some do.

The part of the brain used for thinking, reasoning,  logic and decision making gets bigger mainly just before puberty (usually 11 to 12 years). But the pre-teen brain grows far too many connections and synapses, and during the teenage years these are cut back: dendrites that don't get used fall away and those that do get used get fewer and thicker.

Body clock: The adult human body clock is 'on' for for about 16 hours of the day when we are awake and it is difficult to sleep in this period. While babies need a lot of sleep, by the age of 9 or 10, we tend to have reached the adult pattern of eight hours of sleep. But research shows that teenagers need around nine hours, at the point they also stay up later - so they are not ready to wake at 7am. 

Sleep: If they are woken too early they risk losing REM (rapid eye movement) sleep which is particularly deep sleep, and seems to be important for memory and learning. Trying to catch up by sleeping more at weekends does not help the body clock and may even disrupt it further. And there is now evidence that the sleeping brain practises the things that you did when you were awake. And the brain is also changing physically by pruning some connections and strengthening others.

Risk taking: Surviving risks means the brain releases dopamine so activating the feelings of pleasure, otherwise we become lazy. But some people's brains are more geared to this than others and adolescents in general do take more risks. Also the pleasure reaction is often stronger than the rational (pre-frontal cortex) part of the brain that logically looks at the risks.  The need to impress friends is important for getting on in life, so teenagers often take different decisions when friends are present. And with puberty starting around 2 years earlier than 50 years ago, alcohol is more widely used, as are (increasingly stronger) drugs. 2013: Rates of sexually transmitted diseases have increased, almost a quarter of 15 year olds smoke regularly and a third have tried cannabis, and a fifth are classified as obese. And around 60% of teenage girls are on diets (often not healthy ones). But remember if a quarter of UK teens get drunk at least three time a month - three quarters don't. 

Female and male brains: [The following statements are averages and not everyone's brain behaves in the same way; the brains of some girls work more in a male way, and vice versa. and it's not about being homosexual or heterosexual.] Boys tend to be interested in technical details of (e.g. a mobile phone) and girls more in the appearance and how useful it is. Boys are more likely to be diagnosed with autism, lacking understanding of social skills and bonding mechanisms. However, this may be less so as if is now being recognised that girls can mask the symptoms of autism by copying behaviour to 'fit in'.

The male brain is typically 10% heavier than a female brain but female brains have a greater proportion of the information-processing grey matter. Women are less likely to have dyslexia, language difficulty, colour blindness, schizophrenia, ADHD, Tourette's and other brain disorders. In later life, men lose brain cells faster and are more likely to develop memory problems.

Sex Hormones: these are chemicals that affect many aspects of our lives. When a sperm fertilizes an egg, the resulting embryo always starts out female. During week 6 or 7 the sex hormones either turn  the embryo into a male (testosterone) or keeping it as female (oestrogen). Normal males will have a small amount of female hormones and females a small amount of male hormones. Hormone levels change during our lifetime and are especially active at puberty. They also change with the season and, for women, during the menstrual cycle.

Oestrogen: One effect of this hormone is to boost dopamine, which can make the world seem rosier, brighter but can also make it feel darker and sadder, and it can cause mood swings. But not all females have mood swings. And mood swings are not only causes by sex hormones. Boys have mood swings too.

Testosterone: Increased testosterone causes aggressive behaviour. Testosterone increases during and after intense sport, especially if you are on the winning side - and also if you are a spectator. Females with the condition 'congenital hyperplasia' have too much testosterone; they show more aggressive behaviour and better spatial skills - both of which are more common in males.

Learning: Different sexes may learn better with different teaching methods. For languages, some pupils (especially boys) may need the rules and grammar explained in a very structured way. In science subjects, some pupils (perhaps more often the girls) may need more rote learning, practical examples or a using comparisons or analogies.

Emotional behaviour: Girls start to use their pre-frontal cortex to control emotional behaviour sooner than boys, who may take longer to develop self-control.

Risk behaviour: Boys seem to take more risks and more dangerous ones - not wearing seat belts or helmets, driving while drunk, binge drink and drink heavily, use and deal drugs, smoke, fight and carry weapons, have sex before 13, overeat and so be overweight. Girls' risk taking is more often having sex when they hadn't intended to, fast or vomit to lose weight or avoid physical exercise.

Body changes: Girls start to look like women before boys start to look like men. This sometimes makes girls feel they are fat. Research using pictures shows that women think men like thinner women, while men didn't choose the same photos.

Developing early or late: Either is difficult for both sexes. Early development in girls creates an extra risk of early sex and alcohol addiction, depression, anxiety and eating disorders. For boys, while they may be more popular and given leadership roles, adults may expect them to be advanced in school work too which is unlikely as their frontal cortex is not mature.

Clumsiness: One the areas of the brain that grow the most in adolescence is the cerebellum, which is important in controlling large movements. However the brain may not have completely rewired itself as fast as the body growth. Stress can also cause clumsiness.

Social: Girls are likely to hit puberty just as they start secondary school, while boys have time to settle in before puberty starts. Both sexes may feel less comfortable with their other-sex parent and argue more with opposite sex siblings. It is thought that this is a biological way of preventing incest which can lead to deformities in offspring.

End

Women and Science

Human society is diverse and we should celebrate and treasure the strength in this quality. When you don't have diversity in the creative process, you inevitably end up with a single, narrow, distorted perspective that hinders progress. 

While Aristotle answered the question 'What is the immediate source of the design that we see in living things?' correctly with 'It is the information that they inherit from their parents', there is much that he did not understand. For example, he thought that women were 'deficient' and a departure from the male, and believed that they had fewer teeth than men. But while attitudes to women have changed a great deal, in science as in other areas, women still struggle for the recognition they deserve. 

In the world of science, the achievements of women scientists are often not acknowledged, and are instead attributed to male colleagues. This has been named the 'Matilda effect' after the 19th century suffragist and abolitionist Matilda Joslyn Gage.

This is a problem with our culture, not with science. No major international exhibition of contemporary art has ever achieved gender parity, and it is telling how few women have been thought of as great artists throughout Western history.

Nettie Maria Stevens at Bryn Mawr College in Pennsylvania overturned the idea that the environment was important in determining the sex of a child, when she demonstrated that the X and Y chromosomes are responsible. Her colleague and mentor Edmund Wilson is more commonly cited as the discoverer. Though when she died of breast cancer in 1912, the journal Science referred to her worldwide reputation.

In late 1950's France, the credit for Marthe Gautier's work on the discovery of Down syndrome went instead to a male colleague, Jerome Lejeune.

Marie Sklodowska Curie, of Polish origin but who had to conduct her research in Paris, became the first women to win the 1903 Nobel Prize for Physics. In 1910 she lost the vote over her nomination as a member of the French Academie des Sciences. The following year she won the Nobel Prize for Chemistry, becoming the only person to win the award in two different sciences. The Academie only elected its first female full member in 1979, the mathematician Yvonne Choquet-Bruhat.

In the US, Esther Lederberg deserved more credit for her work in bacterial genetics, including the discovery of a virus that infects bacteria, but was given a shared Nobel prize in 1958 with her husband Joshua Lederberg. Esther was more adept at experimental work than Joshua. A major pioneer of bacterial genetics, Esther discovered the lamda phage, which is widely used to study gene regulation and genetic recombination. She also invented the replica plating technique, which is used to isolate and analyse bacterial mutants and track antibiotic resistance. This work was crucial to Joshua's research.

At the John Hopkins University, Baltimore, US, graduate student Candace Pert helped discover the opiate receptor (the cellular binding site for the body's own painkillers, endorphins, in the brain) and famously protested when only men went on the share the Nobel Prize for this work.

Who knows how different our world would be if pioneers such as Hilde Mangold and Rosalind Franklin had not died so tragically young? It is tempting to think that fertility science would have become more focused on making reproduction easier and more comfortable for women. But we all know that if Mangold and Franklin and other remarkable women like them had lived to an old age, it is doubtful if the dial would have turned much from male control to female empowerment.

Hilde Mangold (1898-1924) was a German embryologist best known for her 1923 dissertation which demonstrated embryonic induction, the capacity of cells to direct the developmental trajectory of other cells. This work was the foundation for her mentor, Hans Spemann's 1935 Nobel Prize for Medicine for the discovery of the embryonic organizer, and remains a fundamental concept and area of ongoing research in the field. Her dissertation is one of the very few doctoral theses in biology that have directly resulting in the awarding of a Nobel Prize. 

Rosalind Franklin (1920-1958) was an English chemist and X-ray crystallographer whose work was central to the understanding of DNA, RNA, viruses, coal and graphite. She is best known for her work on X-ray diffraction images of of DNA which led to the discovery of the DNA double helix - for which Francis Crick, James Watson and Maurice Wilkins shared the Nobel Prize in Phsiology or Medicine in 1962. Watson suggested she receive a Nobel Prize in Chemistry, but the Nobel Committee did not usually make posthumous awards, and are not currently permitted. (If a person is awarded a prize, but dies before receiving it, the prize is still presented.)

The fact is that the heroic narrative of the brilliant scientist who died tragically young has been told many times when it comes to men such as Alan Turing, Srinivasa Ramanujan and Blaise Pascal. But it is only in recent years that the many talented women who died before fulfilling their potential have started to rise out of the murk of history.

In 2020 the gap still remains. A 2018 study of more than 10 million research papers concluded that women were less often in authorship positions linked with seniority. Other studies show that grant reviewers award lower scores to proposals from women. And women often still feel it intimidating to speak in public, and are less likely to ask questions after a talk.

Source: The Dance of Life: symmetry, cells and how we become human. Magdalena Zernicka-Goertz & Roger Highfield. W.H. Allen, 2020.

Everybody Lies: What the Internet Can Tell Us About Who We Really Are

Everybody Lies: What the Internet Can Tell Us About Who We Really Are by Seth Stephens-Davidowitz
[Bloombsbury, 2017    978-1-4088-9471-2]

"This book is about a whole new way of studying the mind. Big data from internet searches and other online responses ... offer an unprecedented peek into people's psyches." Stephen Pinker.

The author is an internet data expert, tracking the digital trails people leave behind as they make their way across the web. He tries to understand what we really want, what we will really do, and who we really are. The book is a fascinating read, and I've just picked out some of his findings.

He accesses a variety of sources, including Google Trends, which tells users how frequently any word or phrase has been searched in different locations at different times. It allows you to compare the relative frequency of different searches, but does not report the absolute number of any search. It also will only provide data when lots of people make the same search. (2021: Google Trends requires a modern browser such as Chrome.) Other sources analysed were Wikipedia, Facebook profiles, Stormfront, PornHub and other Big Data sources. And it turns out that people lie to friends, lovers, doctors, surveys and themselves - but on Google they share embarrassing information.

Racial prejudice in the USA. Barack Obama won the 2008 US presidential race rather easily and the polls suggested that race was not a factor in how people voted. But Google Trends showed that on election night, searches and signups for Stormfront (a white nationalist site) were ten times higher than normal. And surprisingly, places with the highest search rates included upstate New York, western Pennsylvania, eastern Ohio, industrial Michigan and rural Illinois alongside West Virginia, southern Louisiana and Mississippi. This suggested that the true divide was not South versus North, but East versus West and that plenty of Democrats have racist attitudes.

The cause of racism is typically thought to be economic insecurity and vulnerability, but neither racist searches nor membership of Stormfront (a white nationalist site) rises when unemployment does.

Many people tell pollsters they intend to vote, but don't actually do so. Google searches for 'how to vote' or 'where to vote' more accurately reflected actual turnout. Seemingly neutral searches that include the names of both candidates can give a clue to voting intention, with the preferred candidate usually the first named. And the secret racism was a likely factor in Trump's election.

Surprisingly searches reflecting anxiety don't rise after terrorist attacks. Searches for jokes are lowest on Mondays, the day when most people report they are unhappy, they are lowest on cloudy or rainy days, and plummet after major tragedy.

While larger datasets can be useful in some situations, in others it is more important to have the right data. What symptoms best predict pancreatic cancer? Researchers found that searches for back pain and yellowing skin, or indigestion and abdominal pain were most likely to be made for those later diagnosed with the cancer.

There is a basic human fascination with the dramatic. In a survey people ranked death by tornado as more common than death from asthma, but asthma causes about seventy times more deaths than tornadoes. But tornado deaths get in the news,while asthma deaths don't.

What are the chances of becoming a basketball player? It is commonly held that most NBA players grow up in poverty, combining a range of data says not. In fact you are more likely to succeed if you live in a wealthy county of the US, with a comfortable family life and have a common given name - plus, of course, being tall. 

Buying wine? A big percentage of the quality of a wine is down to the weather during the growing season. Warm weather and early irrigation are needed for the best grapes. So if thinking of buying a 2016 bottle, you need to look at the weather that year where the grapes were grown.

Democrat politicians use terms such as estate tax, privatize social security, worker's rights and poor people while Republicans refer to death tax, reform social security, private property rights and government spending. Sometimes it is using different terms for the same concept. Republicans described the federal inheritance tax as a death tax, Democrats as an estate tax. if an area is generally liberal, the dominant newspaper will tend to be liberal and the market determines a newspaper's slant more often than its owner's views. And newspaper readership tilts a bit left on average.

And it turns out that people lie a lot, often the little white lie. A 1950 election survey in Denver found that far more people said they were registered to vote, voted last presidential election, voted last mayoral election, gave to a recent Community Chest charitable drive than actually happened taken from official counts. Giving the wrong information made people look good to others, even in a situation where they were not identified, while some people even lie to mess up surveys.

Surprisingly the internet news industry is dominated by a few massive sites. Therefore they tend to cover a wide range of subjects and views to appeal to the most people.

Data reveals that child abuse does not lessen in hard economic times, it just gets reported less. Women search more often for self-induced abortion in areas where it is hard to get a legal abortion.

On social media there is no incentive to tell the truth; on the contrary there is incentive to make yourself look good to friends, family members, colleagues and strangers. Family life seems perfect, and young adults are always at cool parties on Saturday nights.

In 2006 Facebook launched News Feed which gives users updates on activities of all their friends. While some saw this as stalker activity and tried to get it removed, Facebook saw that people were staying far longer on the platform. News Feed is still there.

Google searches show that you are not alone. The questions you don't raise in person as they sound too silly but they can alert us to people who are suffering. Analyzing these anonymous searches can assist agencies working in specific concerns. E.g. Child protection agencies could target resources to specific areas. And searching can lead us from problems to solutions. 'When we lecture angry people, search date implies that fury can grow. But subtly provoking people's curiosity, giving new information and giving new images of the group that is stoking their rage may turn their thoughts in different, more positive directions.'

What baseball team is doing well when a US boy is around 8 is likely to remain their lifetime team to support. For female baseball supporters, it is more likely to at age 22. Our political preferences are also linked to specific periods. Between the ages of 14 and 24, many Americans will form their views based on the popularity of the current president; the views will, on average, remain constant a lifetime.

There is a popular view that watching violent films encourages people to commit violent actions. It turns our that if watching such films at a cinema, where alcohol is not available, actually reduces crimes.

Doppelganger searches for someone who is as near as possible your exact match is used in some form by Amazon to suggest other books you might like, and Pandora to suggest songs you might want to listen too. But it can also help in medicine by finding others with similar symptoms; this can narrow down diagnoses, especially where the condition is rare.  

Many people play a lottery, but few win. But does winning make you happy? Not in the short term it seems, but longer term generally yes. But if someone wins and starts buying items such as an expensive car, neighbours are significantly more likely to go bankrupt attempting to buy likewise.

Money lenders want to assess the likelihood of borrowers repaying the loan. A research study showed that terms used by people researching lenders can indicate the most likely to repay (debt-free, after-tax, graduate, lower interest rate and minimum payment) or to default (God, promise, will pay, hospital, thank you). But this raise some ethical questions - is it acceptable? 

The ability to zoom in on gambling customers it potentially dangerous. Casinos know that every gambler has a 'pain point' when the level of losses frightens the player such that they stop for an extended period. So they try and make sure that the gambler gets close to the pain point but not quite there, for instance, by offering free meals. They use doppelganger methods to establish the likely pain points. 

Education research. Anonymized children's online behaviour can reveal how they are learning and developing. How is their spelling - does it indicate dyslexia? Do they have friends. Are they becoming more mature. Education software companies: with EDU STAR students log in to a computer and are randomly exposed to different lesson plans, then take a short test to see how well they learned the material. Schools can therefore learn what software works best. This can yield surprising results as students who were taught fractions via a game tested worse than those who learned in a more traditional way.

END

 

Long-term Vaccine Safety: the Facts

Still commonly shared online, the claim that we don't know the long-term side effects of  Covid vaccines is untrue. In fact in the scientific and medical world, a year is considered 'long-term' when it comes to vaccine safety.

It is now (25th Feb. 2022) more than 14 months since the first Covid-19 vaccine dose was given, and a year since the first delivery of Covid-19 vaccines under the Covax scheme. Scientists explain that this is more than enough time for all but the rarest side effects to have emerged. 

In fact the number of people who have received vaccine is more important than the length of time vaccines have been in use. New vaccines undergo stringent procedures to identify (a) whether it works, (b) if there are any side effects and (c) are the side effects mild or severe. In normal times, vaccine trials have gaps between the different stages due to researchers obtaining funding for the next stage. With Covid-19, funding was made instantly available, thus shortening the time from concept to production.

What happens in your body?

Covid vaccines may be new, but the processes they trigger in your body are not, and we know how the immune system works. Understanding how they stimulate the immune system can help us understand how quickly we can expect to have any negative reactions. 

After 15 minutes

• A tiny fraction of people will have an allergic reaction to the inactive ingredients in the vaccine and this will happen within about 15 minutes of receiving it.

After a few hours

• Shortly after receiving the vaccine, the immune system recognises an alien invader and attacks it with immune cells, the weapons it would use against any virus or bacteria.
• In this innate phase, any reactions will happen within hours or a couple of days, including the most common side effects of a sore arm, temperature and other flu-like symptoms.
• Also in this phase is a much rarer side effect which has been linked to the mRNA vaccines Moderna and Pfizer is myocarditis (inflammation of the heart).
• While the exact cause of myocarditis is not understood, inflammation is one of the body's responses to infection or injury.
• Vaccine induced mycarditis is generally mild, and gets better on its own or with basic anti-inflammatory drugs such as ibuprofen.

After 10 days

• The innate phase also starts the second phase of your immune response - the adaptive phase - where your body starts to make cells which are specifically tailored to fight off the target virus. 
• As this phase starts around 10 days after infection, which is why vaccines will take this length of time to begin to have an effect in protecting you against Covid. 
• Your body pumps out new immune cells, peaking after about two weeks and fading away after about 28 days. 
• A very rare but serious side effect linked to the Astra-Zeneca vaccine (a specific type of blood clot) happens during this phase and is related to the antibodies produced by your immune system in response to the vaccine. That is why most of these rare clots have been seen within four weeks of vaccination.

By 28 days

• Once the adaptive phase dies down - after about a month - you are left with memory cells which give you protection for months or years after initial exposure but don't generate new responses. If you have not a reaction after the first couple of months, it is incredibly unlikely that anything that happens after that will be caused by the vaccine.
• While there is never a 100% guarantee with anything in medicine, vaccination history shows that most side effects occur within hours of receiving the vaccine, and rare side effects within days or weeks.  

Will we identify new side effects?

• From our hundreds of years of knowledge showing how the immune system works, an individual who has not had a reaction to a vaccine in the first couple of months, is vanishingly unlikely to have any new side effects after that.
• Countries world wide have put systems in place to monitor side effects and to share that information with each other. 
• It is these systems that picked up both the blood clots and myocarditis, which are extremely rare with only a handful of cases per million doses.
• While milder symptoms (e.g. sore arm or temperature) are likely to be under-reported, the more severe side effects are thoroughly recorded.
• Billions of doses have already been given, so any side effect not yet seen would be rarer than one in a billion.
• While the vaccines have all completed the expected three phases of trials that usually take place before being offered to the general public, they are still being carefully monitored until at least 2023, to make sure even the rarest of events are identified.

And remember....
All the evidence suggests that the overall risks of catching Covid far outweigh any risks from the vaccine.

Source: Covid: How we already understand long-term vaccine safety by Rachel Schraer (BBC Health and misinformation reporter)