Stress inner ear

Whale earwax has been studied to unlock the chemical history of the oceans^[1]. Forming as a plug, whale earwax has rings in it like a tree that map the history of their hormones – letting us know when they were under stress, for example – and the chemicals they were exposed to. This has allowed chemists to assess which substances such as drugs and fire retardants make their way into the environment and are potentially ecologically harmful.

More recently, researchers have begun studying the chemistry of earwax in humans^[2].

 

Anatomy of the ear. By BruceBlaus via Wikipedia Commons.

Isolation and the Brain

As babies, we are all born with vastly more neural connections than we need^[1], and these connections get 'pruned' as we go through life, cutting out the unused ones, strengthening most the ones we use daily^[2].

As social animals, we learn best and develop neural connections by interacting with others. So what happens when our brains are isolated – when we don't see or interact with other people for... months?

© TWDK

One BBC Horizon experiment subjected volunteers to 48 hours isolation in complete darkness: devoid of external sensory stimulti, they started to hallucinate. In the equivalent on Channel 5 (In Solitary: The Anti-Social Experiment), participants took in three items to distract themselves and fuel their resolve. Some people took in personal items that carried meaning – but quickly found these intensified feelings of desperation and homesickness; others took in activities to keep them physically or mentally stimulated, and it was these that were found to be most effective. Scientists think this is an essential coping mechanism for staying mentally healthy in isolation. In the longest isolation experiment, undertaken by Stefania Follini, who spent 130 days underground, the interior designer occupied herself with martial arts and decorating her cave.

Categorising Things is “Evil”

We label things every day: that man is tall, this book a thriller, leaves are green. How tall? How thrilling? What shade of green? We take the relative and make it absolute, categorising the life out of it to streamline communication. Labels are the oil on a squeaky gate, and most people never question them.

When I was a child, I hated labels: they didn't make sense to me. Was a tall child tall, or short because they were a child? What if my eye colour wasn't an option on the list? Why did we need to classify books anyway, and where did one genre end and another begin? Wasn't it easier to just describe them? ...Surely that's what blurbs were for.

Categories lead to bad writing. If you learn that everybody can be described as a tall, frizzy-haired bossy woman, you always tell – and never show. Telling is boring. It loses the magic and the mystery of the woman who peers down between dark, raggedy fronds with a floating look and says tartly, "I told you to put the other end on first!"

I resisted for a long time. Declined to answer; drew an extra box on the multiple choice question. But eventually I was indoctrinated. How? Why?

...If you get told something often enough, again and again and again, it starts to sink in. Perhaps you don't understand the categories, but you can pick from them (even if you pick wrong). My teachers needed me to say that my character was bossy so they could prove I understood what adjectives were. Friends had to like the same genre of music. The NHS wanted to classify my growth rate. So I shut up and categorised for an easy life.

Science uses categories all the time. Species separate from species (did you know the only taxonomic difference between moths and butterflies is that butterflies are prettier?). This is incredibly useful for explaining the patterns and rules in science, but it's also limiting. As we discover more science, we have to revise our categories as they no longer make sense: such as the advent of DNA, which gives us new insights into how animals are related, or the discovery that electricity was the flow of negatively charged electrons, which revealed that our "conventional current" arrow went in the wrong direction!

In learning institutions, even the science subjects are carved up and divided: physics, chemistry, biology, maths… Perhaps, then, it should come as little surprise that so many of the unanswered questions in science take place at the intersection of these fields. To answer them, we need people who are experts in different fields talking and working together, but we actually need more than that: we need polymaths, people who are computational biologists, physical chemists, scientific philosophers, and so on…

I had a quick look at the Things We Don’t Know database, and picked out just a few very fascinating things that cross over scientific fields, from biology to physics to chemistry to computer science to geology to engineering to psychology… and so on ad infinitum. These are they:

Could robots soon have 'human-like' vision? 
Research has been carried out into replicating the muscle motion of the human eye using soft materials and pressure-sensitive piezoelectrics. This could allow robots to "perceive" the world in a way we find more intuitive, and may even help us learn about human visual processing.

Could we capture and store our waste carbon dioxide? 
Scientists think that up to 90% of carbon dioxide emissions could, instead of being released, be captured and stored underground or underwater, where, at great depths, high pressure cause it to liquefy. In the ocean, it shows “negative buoyancy”, sinking to the sea floor, whilst in rocks it can be drained into tiny natural pores in rocks: this is called geological sequestration. Scientists are still exploring where this could take place and how long the carbon dioxide could be stored.

Could we treat mental health problems with birdsong? 
Humans may get psychological benefits from listening to bird calls, including boosts to mood, attention and creativity. This “biophilia” – the idea that being amongst nature makes you happier and healthier – is sufficiently established that Alder Hey Children’s Hospital in Liverpool play birdsong in their corridors, as does an airport lounge in Amsterdam! It’s even been applied as a form of dementia treatment. New work led by the National Trust aims to explore how human brains are affected by birdsong.

How can we measure uncertainty? 
Entropy is a measure commonly used thermodynamics to assess the disorder of a system. However, computer scientists and cryptographers now talk about information entropy. The greater the uncertainty about something, the more information is needed to describe it – so the more entropy or disorder. How did photochirogenesis evolve? Photochirogenesis – the development of handedness in biological molecules (where all natural molecules are either left or right hand mirror images of asymmetric molecules), may have developed because of polarised light in meteorites. If this is true, the origin of life could be in stars.

Is time in our minds? 
Is time an illusion? How can we tell? And, if it’s just in our minds, why is it used in classical mechanics equations? Does time really only go in one direction, or is this an illusion of human perspective? Our current direction through time is always forwards by definition, but on what grounds do we define it like this? Underpinning this could help us understand the concept of time travel and the science behind what we really mean by it.

And on that philosophical note… If you or someone you know is working on one of these topics, we’d love to hear from you. Perhaps you can tell us more about how your research is going, or some of the challenges in the field!

I was inspired to write this post after hearing a talk by Dr Julia Shaw on the label “evil”. 'Evil' throws up all kinds of problems not only because it's a highly subjective category (like most), but also because it sticks. Once labelled evil, you are evil forever. You can live a good life, behave well, be compassionate, but screw up once and you are evil. Your misdeed will be carried with you forever and you can never shake off its label. Evil is immortal.

Depression During and After Pregnancy (Things We Don’t Know about Pregnancy Series #18)

Postnatal depression is thought to occur in ~1 in 10 mothers, making it a common form of mental illness. The onset and peak of the illness may be weeks or even months after the birth of a baby, and the condition lasts for weeks, months, or longer.

Symptoms

The condition is characterised by persistent negative feelings – towards yourself, your baby, and things you previously had an interest in. Most parents find their inability to bond to their baby most upsetting, and many feel guilty, hopeless, and even suicidal. Physical symptoms include disturbed sleep, tiredness, increased or decreased appetite, and difficulty decision-making.

We don’t know what causes postnatal depression

We don’t know what causes postnatal depression, although it’s associated with hormonal changes, such as a drop in one hormone called allopregnanolone. But these alone can’t explain everything. Women go through huge and varied hormonal changes during pregnancy and early motherhood, and postnatal depression doesn’t effect everyone. In fact, for a long time, people believed that pregnancy hormones were protective against depression, and it was simply something new mothers couldn’t get – leading to many undiagnosed sufferers^[1].

Worried Woman Image credit: RyanMcGuire (CC0 Public Domain via Pixabay)

Birth trauma (Things We Don’t Know about Pregnancy Series #17)

PTSD (post-traumatic stress disorder) is still a condition associated with soldiers. Men. But every year, estimates suggest 4% of births cause maternal PTSD ^[1]. We call this birth trauma.

Birth trauma was first recognised in the 1990s, when the American Psychiatry Association modified its definition of a traumatic event. It’s now thought that it may affect fathers who were present at the birth as well as mothers.

I recently visited the Oxford Spires – a midwife-led unit where mothers with no complications can give birth in a relaxed environment. It sits conveniently a few floors above the main hospital, so emergency treatment is only a lift journey away. But amongst the pools and mood lighting, the giant squashy birth aid balls and the ergonomic beds, I was struck by how much could go wrong during birth.

And I don’t just mean physically.

Obstetric forceps. Killian 1842 via Wikipedia Commons.

The Call of the Void

Apparently, I experience ‘High Place Phenomenon’.

As a climbing instructor, I’m used to people saying “I can’t go any further – I’m afraid of heights.”

And I always say, “So am I.”

Of course I am. Everyone is. We just develop strategies for managing that fear, and some manage it better than others. The first time I climb somewhere new, I can feel the fear eating away at me, like a voice in my head saying “Oh god, oh god, oh god.” My strategy is just to get to the top and get it finished – and once I’ve done that, going up again has lost its dauntingness.

It can even feel exciting. I’ve oftentimes sat on the edge of a ledge preparing to belay and realised how easily I could unclip and jump to my death. The thought of the rush of the world shooting past, the feeling of somehow having triumphed over my survival instincts and beaten nature, the sense of freedom, power, and the excitement tremble through me. I’m drugged up on adrenalin. My fingers move instinctively with the rope – and it’s a good job they do, because my mind is addled.
 

Looking down from above. Image © Thing We Don’t Know.

Does this sound familiar? 30% of people experience it at least once. The French call it l’appel du vide – the call of the void – and that is exactly what it feels like to me. A beckoning. As though someone were on my left shoulder... whispering, “Do it!”

Male vs Female Brains

Women are from Venus and men are from Mars, or so we have long been told. There are obvious physical differences between the sexes, but do these disparities extend to our brains? And if there are sex differences to be found in the brain, are they there from before birth, or are they a product of our upbringing? As well as being interesting areas for scientific study, these questions open up some ethical conundrums - if we did find robust, biological sex differences in the brains of men and women, what would this mean for how we should treat the sexes, and how we should raise our children?

We all have one of these - but are men's and women's brains different?
Image credit: Anatomography, via Wikimedia Commons [CC BY-SA 2.1 jp]

The first, and probably easiest, question to answer is whether there are physical differences in men's and women's brains. We know that males tend to have larger brains than females, and this has been confirmed by a recent meta-analysis^[1]. But do these physical disparities correspond to a difference in ability, or function? Some have argued that larger brain volume suggests greater intelligence, but it is now widely accepted that total brain volume is not a very good indicator of intelligence - Einstein’s brain was actually found to be slightly smaller than average^[2]. A criticism of many studies on brain volume is that they fail to take into account that women, on average, have smaller bodies than men - so it seems reasonable to expect their brains to also be smaller. However brain to body size ratio can’t account for the dissimilarities completely - the correlation between the two is not strong in humans, and boys’ brains remain bigger even at age 11-13, where their bodies are, on average, smaller^[3].

As well as looking at the brain as a whole, researchers look at specific structures inside the brain to see if there is divergence there. The same meta-analysis found size differences in a huge number of structures in the brain, including the amygdala, which is involved in emotional processing and the hippocampus, which is important for memory. Again, these differences weren’t adjusted for the overall distinctions in size between men & women, but as the variations in size and connectivity differed by region it seems it is not just as simple as every area being bigger in men. Discrepancies have also been found in the percentage of grey matter and white matter in the brains of men & women^[4].