Why might billions of brains be doomed?

Yes, this is a blog about brains, but if you’re determined enough, you can contrive to use that as a starting point for pretty much any topic. This post was prompted after watching the HBO series Chernobyl. It occurred to me that the meltdown may have doomed our entire species, in spite of the heroism of the various Ukrainians involved in the damage control. We’ve not been condemned by radioactive waste, but rather, the fallout has been fear of nuclear power. Had nations across the globe continued to expand our nuclear energy infrastructure through the 80s, 90s and 00s, then millions of tons of carbon dioxide released from coal and gas might have been spared. Counter to our fears, nuclear waste isn’t what’s set to cause the most dramatic, planet wide mass extinction since humanity started up.

This is going to be a post that focuses on climate change. If you’ve only got a short while to spend on idle interneting, then I will be delighted if the only part you take note of is the first step – it is the science, not my meandering arguments, that I hope will most impact you.

Step 1
Read the IPCC’s 2018 report on the state of play and then these reports (2) (3) of what happens when a neutral risk assessment is undertaken bearing in mind the best climate change data we have.
If you’re more of a video/audio learner, this presentation (link starts at the juicy part, but it’s all good/devastating) by Professor Kevin Anderson from the University of Manchester, and this presentation from Extinction Rebellion covers much of what I’m going to talk about.

Step 2

Accept that whilst some of the projections lie outside the scientific value of publishable certainty, they are all credible possibilities. Neat statistical ‘significance’ doesn’t translate cleanly to the decision making one has to make when the stakes are mass human extinction – as XR put it, “you wouldn’t put your children on a plane that has a 1 in 20 chance of crashing”, and “you don’t wait until you’re sure you’re going to hit the iceberg before you start turning your ship away from it”.

Step 3

Appreciate that the death toll has already started, and it will in our lifetime, have a real chance of reaching the billions no that can’t be right. millions. oh shit. tens or even hundreds of millions. Humans all over the world, starting in (but not limited to) developing nations, will begin starving or droughting* to death as crops and soils fail, succumbing to novel pandemics and diseases for lack of clean water, or being killed in worldwide conflicts over what little food and water remains available to us. These numbers are not the figures you will see in the IPCC’s report, but are derrived from a credible scenario based study that incorporates factors of salination of river deltas and the mass migration that sea level rises will precipitate. As sea levels rise, up to a billion people on the planet will need to be relocated, and up to two billion more will have a strain on their supply of fresh water.

Step 4

Before you think this isn’t likely to affect you, just know that the city of London contains enough food to support itself for just 3 days, and depends on a diverse and sophisticated, but not invulnerable, supply chain that could easily be disrupted by something as mundane as a 4 week long heat wave of 55°C – As pointed out in the above video by Prof. Anderson, “there is a widespread view that a 4°C [temperature rise] future is incompatible with an organised global community, is likely to be beyond ‘adaptation’, is devastating to the majority of ecosystems and has a high probability of [continuing to increase to even higher temperatures]”.


Now you’ve undertaken these steps, I present the ‘Choose your own adventure’ options below:

  • “I always vaguely knew we were headed for disaster in the future, but until I can’t get avocados from my nearby cafe it doesn’t really concern me”
  • “Well at least the people in power are making changes to sort out this mess”

Human brains and the societies they precipitated did not evolve to deal with many/any of  the challenges of the modern age. Put bacteria in a petri dish tailored just to their liking, and they will expand and consume with reckless abandon until all the jelly is depleted, and they themselves expire. So too will a capitalist global society that is capable of total exploitation of its planet’s limited resources.

One can apply the basic principles of ‘survival of the fittest’ to the various forms of government that have developed over the last few hundred years across the globe. Part of that survival is a resistance to rapid change in the absence of a readily apparent existential threat or cake deficit, and rapid change is certainly what is required for us now.

The First World War killed just over 1% of the global population, and the Second World War killed 3%. These two incidents produced the more or less unheard of circumstances of ‘Total War’. Entire continents transformed their whole societies and economies to serve the war effort. In a matter of months, millions of people were compelled by their governments to sacrifice either their lives, or the quality of their foods, pastimes and freedoms. But in both of these cases there was an enemy you could point a finger at, no shortage of capitalists that had everything to gain from war profiteering, and the cheerful notion that this hardship would all be over by Christmas.

The scale of global human deaths and displacement that a 3-4°C increase would precipitate is unlike anything our current political system has ever dealt with. The Black Death in the 1340s killed off somewhere between 30-60% of Europe’s population (~22% of the global population of ~450 million) but the expert opinions for the levels of displacement, food shortage and disease are in the billions (vs. the 20 million people displaced in WW2). You’d think that would be enough to kickstart some pretty drastic changes.

The following excerpt is from the ‘What Lies Beneath‘ report cited above, which I highly recommend. It is one example where I found actual numbers put to the resultant human population reduction – such speculation is based from the most extreme outcomes of ‘hothouse earth’ scenarios, and includes the sum of previously mentioned factors such as war, famine, disease, flooding and extreme weather.The 80-90% reduction of global population mentioned is a dramatic figure that seems to be cited from a presentation about 8 years ago, but I’ve got in touch with the author of that presentation to establish from where it was derrived. Regardless, it does seem to offer a frightening upper limit of the destruction we could be exposed to if we don’t act – more conservative estimates (acknowledged recently by the WHO to be significant underestimates) are in the region of 250,000-750,000 additional deaths per year as a result of climate change.

Miscellaneous reference

Excerpt: ‘What Lies Beneath’ Page 14 



What has the UK (best of the bunch of the G7 nations) achieved in the last decade?

  • A target of being carbon neutral by 2050 (when we are already not meeting our previous target for 80% reductions).
  • Cutting our coal usage massively, mostly through burning more gas (this has been our single biggest win).
  • Promised to invest in wind power, (though the land/sea area needed to make up our shortfall in energy is around the size of Wales)
  • Projects for 3 out of 6 new nuclear power stations abandoned  due to lack of governmental funding (which means that we’ve left ourselves with no more room to cut carbon output when it comes to electrical grid energy).
  • The nebulous plan of carbon capture which is still magnitudes of scale away from viability.

It is almost depressing that the UK have been doing the best out of our G7 colleagues (And Agent Orange might end up in power for another term), but even the above leaves an enormous amount to be desired. This presentation in the French Parliament a few days ago highlights how far short we are falling. The reason for this lacklustre response?

I’d make the case that its because the threat we face is not born from an overseas villain our Western populations can demonize – it is ourselves. When has a population ever shouldered such responsibility, when there exists the opportunity to shirk or deny it?

The mighty economic machinery of a war economy, which by 1918 had taken just 4 years to transfer the much of the accumulated wealth of 330 years of British Imperialism to the USA, is not on our side here either. Simply look at the fossil fuel industry’s cover-up of climate change data and ongoing lobbying against climate change policies. Furthermore, the very valuation of such companies is derived from their plan to burn every last gram of dinosaur-juice they have in their wells. Aside from fossil fuels, any meaningful climate change strategy will necessarily involve a massive curtailment in consumerism – personally owned cars, regularly refreshed wardrobes, and an all-season-round food availability will all become things of the past. Not exactly the capitalist’s wet dream.

And what’s worse, is that these curtailments aren’t just for Christmas. The threat of a runaway greenhouse effect is here to stay for the indefinite future of our species. There’s no light at the end of the tunnel in this regard, and millions of tons of coal and oil is going to have to stay underground for us to avoid truly apocalyptic temperature rises.

There is no way of tackling climate change that does not restrict the current freedoms enjoyed by the wealthier members of our global population. The freedom of movement needs to be restricted through financial or other means, to start to curtail the ever increasing impact of 1.32 billion active road vehicles4.3 billion flights each year alone and 53,000 merchant ships to continue to pump greenhouse gases into our atmosphere.


So how do we fix it?

Well the first thing to do is write a nice long blog post about it. You’ll feel much better then. You can also agonize over whether donating to Extinction Rebellion or The Climate Coalition will end up with your name on an eco-terrorist watchlist.

Afterwards, consider petitioning your local MP for whichever you think is most sensible from the following options. I’ve found the most effective way to submit these sorts of things is to scrawl the suggestions on waste cardboard, tuck it into a glass bottle and then drop it to a nearby recycling plant… but you could always try an email.

  • Total war scale, societal and industrial changes in
    • transport – massive curtailment in non-public and aviation travel.
    • food – huge restrictions of dietary variety and likely vegetarianism/veganism by necessity.
    • housing – compulsory insulation of every household, replacement of every gas heater with electric
    • waste avoidance and reduction
  • Significant expansion of nuclear, solar and hydroelectric energy.
  • Compulsory carbon costing on every product and company logo, akin to the dietary traffic light system, with associated taxation.
  • Mass re-forestation (this might actually work!)


Our planet, as Professor Anderson states, is heading towards a global system wide change. We might still have a very short window of time to determine the nature of this change.

We can have our diets changed either to predominantly vegan/vegetarian through collective conscientiousness, or to the diet of mass starvation through global crop failure.

We can choose to vastly reduce our flights around the world to limit our carbon footprints, or have viable destinations reduced to rubble through war or desert through war and drought.

We can take family planning seriously, or have our plans for families torn apart.

We can use our brains to avert this catastrophe, or let countless millions of minds suffer the consequences of inaction.

In the end, the choice is between putting pressure on our government and the international community to act drastically now, or suffer the loss of having any palatable choices to left to make.

*NB. ‘droughting’ is barely a word, and I use it only because we don’t have a neat word for ‘death by dehydration’. Interestingly I’ve seen it argued that this is because merry old Britain is too rainy for the English language to have needed one.


And so ends medical school

This self-indulgent little spiel was conceived after my audiobook ran dry during a long drive south from Stoke on Trent. I’ve neglected this blog for far too long, and felt the end of my medical school career warranted some brief mention. Anyway…

I’m about to become a doctor. I graduate on Thursday the 7th of July, and am given my provisional registration with the General Medical Council on the 25th July 2016. This will mark a rather extreme transition of state, from the infamously carefree life of a student, to all the responsibilities and expectations of “being a doctor”.

As I approach this stark threshold, I’ve been looking over some of the angsty reflections I’d indulged in as a teenager (thankfully before I was given a blog), and it’s been a bit like bumping into an incredibly inebriated version of yourself a few hours before you leave for a party.

I am writing this in part so that Dr Low of 2022 can look back on what was on the mind of Mr Low of 2016 in (presumably) the same way. A lot more seems to have happened in the 6 years of medical school than the half dozen years preceding it – whose meagre highlights were video games, music and the romantic tact of an adolescent whose best (read: only) line was “I’m in a band…?”.

Since then, my repertoire of emotional and romantic discourse has expanded hugely. I’ve managed to get this far with Mei partly on the back of “I won’t always be this useless – I’ll be a doctor in a short while, and I’ve heard they’re great!”

Dinner table talk – albeit some that can cause the more soft stomached of my friends and family to groan, has certainly improved. I’ve seen internal organs inadvertently delivered via C-section, only to be frantically reinserted (twice) by incredulous obstetricians. I’ve called over doctors to help resuscitate a patient we’d previously declared dead after 6 rounds of unsuccessful CPR, when I noticed he’d started breathing again of his own accord. I’ve helped out a man stabbed at Kentish Town station, and had to explain to my flatmates why I was covered in blood, and “no it isn’t mine”, and “no you don’t have to keep glancing at the nearest exit”.

All in all, it’s all been rather exciting, and if you or someone you know want to embark on the process of becoming a doctor, I can’t recommend it highly enough. Medical school can be a great way for sheltered white heterosexual cis-males to gain a sense of perspective in this exciting world.


If you’ve ever seen a man’s scalp peeled off and folded over his face, so that a plate of skull can be removed to expose the brain’s protective sac, you’ll perhaps have a sense of how hard it is to get brains to open up. Especially when there’s something going wrong.

The brain pulsates with each heartbeat, as the vascular neuronal jelly is pumped with oxygen and sugar rich blood. If starved of either of these for even a matter of seconds, it is irreparably damaged, and the consciousness it gives rise to can be permanently altered or destroyed. But that’s not the only thing that can go wrong in this fragile bag of saltwater and fat. The brain is built from biochemistry, in the same way a computer chip is comprised of silicon and conductors. But just as an OS can crash or slow without an obvious physical insult, so too can an abstract entity such as consciousness. Produced by the machinery of millions of networks of cells, our minds can go askew without a bleed, stroke or bullet. At least 1 in 4 of us will experience first hand the trials of mental illness. I want to briefly discuss some of the prevailing theories of what goes on in the darkness behind the eyes, in one of the more misunderstood dysfunctions of the mind, schizophrenia.

To begin, it is worth mentioning that schizophrenia is more correctly referred to as a collection of symptoms or a ‘syndrome’ than a specific and easily defined disease. It is a long term mental health condition, said to be a ‘psychotic illness’ – a term meaning that it can cause the sufferer to become unable to distinguish their internal thoughts and imaginations from their external reality. It cannot be emphasised enough, that the condition has nothing to do with a ‘split personality’, and that people with the condition are very rarely dangerous. It affects roughly 1 in 100 people at some point in their lives. Delusions, disorders of thought, and auditory hallucinations are said to be ‘positive’ symptoms of the condition, in the sense that they are an unwelcome addition to the content of a mind, whilst reduced emotional and social engagement are described as ‘negative’ symptoms, detracting from the original functionality and well-being of a person’s personality.

Before I discuss the proposed neurological mechanisms of schizophrenia, I’d like to be clear that the hypotheses  to which I will allude are not suggested to be the complete explanation of the syndrome, and my explanations of them are at best grossly incomplete. In spite of this, I hope this simplified explanation is a helpful starting point for anyone looking to further their understanding of schizophrenia, and might dispel some of the mystique that exacerbates the stigma of this branch of mental illness.

Schizophrenia is thought by some to be a ‘disorder of salience’. One of the key evolutionary advantages of humanity’s unique consciousness, is the ability to pick out minute features from the monotony of our lives, and see significance and importance in stimuli that would fail to faze even the most neurotic antelope. Noting the value of a particularly sharp rock for use in an abstract construction like an axe or spear, or picking up on the increasingly subtle social cues of a developing tribal society, warranted the evolutionary refinement of a mechanism by which we could pick the wheat from the chaff.  Our brains are capable of extraordinary and often totally subconscious multitasking, to the extent that we are often totally unaware that we’ve adjusted our sitting position a dozen times since we started reading a blog post about schizophrenia. The experience of residing in a body that’s half run on autopilot is universal, with cereal boxes being put ‘back’ in the fridge, and commutes to work occurring at weekends (sometimes even by doctors /s). But all the while, each part of our sensory input is mutely inspected, and assessed for novelty or significance by some part of our mind, drawing our attention to visual and audio cues that might make us put the lid back on the milk or tidy up a discarded Doctor Who sock in response to a frustrated sigh.

This flavouring of otherwise neutral and unremarkable stimuli with a sense of importance, leaning towards either attractiveness or aversion, is attributed to the ‘mesolimbic pathway’ or ‘reward pathway’, which uses the chemical dopamine as its pepper.

What happens then, when this process goes awry, and all the pepper spills into the soup? When the gain is turned up too high, be it through genetic or environmental factors (especially the judicious consumption of THC), a mind can begin to perceive significance in anything, from the car parked outside the house, to the tie worn by a news presenter. When a mind is faced with the knowledge that there is ‘something’ important about the way your neighbour said “hello!” yesterday, as well as the fact the batteries in the remote need changing, it will often construct a narrative to make sense of it all. The nature of this narrative will vary from person to person based on their cultural background, with explanations ranging from governmental conspiracies to religious, supernatural or extra-terrestrial encounters. Such narratives, whilst partly derived from a person’s environment, are classified as ‘delusions’ or ‘false beliefs’ when they fall too far from the social norms of their community. Similarly, ‘delusions of reference’ occur when a sufferer perceives a personal significance to something said by a public figure or newspaper, and will often incorporate it into their delusion.

Auditory hallucinations – ‘hearing voices’ – a classic hallmark of the syndrome of schizophrenia, can also be explained through excessive dopamine signalling.  Such signalling has been shown to cause abnormal connections between the sites of the brain that produce language (Broca’s area) and the part of the brain which understands it (Wernicke’s area). In the way the brain adapts to these abnormal connections, new links are then formed between Broca’s area and the centres that are responsible for processing auditory information. Once this has occurred, the auditory system, unable to discern the source of this speech, attributes it to an external source. In the context of a mind already perceiving conspiracy and threats at every corner, the content of this speech can often be alarming, and might take the form of ‘third person’ commentaries of the sufferers actions, or, more worryingly, ‘second person’ commands, which might compel the sufferer to odd behaviours, or even self-harm.

This hypothesis of ‘aberrant salience’ (Kapur 2003), and the ‘dopamine hypothesis’ were proposed based on the fact that the blockage of dopamine receptors through certain antipsychotic medications seems to help alleviate some of the positive symptoms of schizophrenia, whilst conversely a potential side effect of medications that stimulate dopamine receptors is psychosis. Sadly, it remains clear that this isn’t the whole picture, with some patients failing to respond to such medications, and other medications working through totally different receptors and transmitters in ways we are still yet to fully understand.

The negative symptoms I mentioned previously, as well as the complex relationship with depressive illness and anxiety disorders also remain poorly understood, and difficult to treat. Alternative and additional theories of schizophrenia, both neurological and psychological, will all reflect and explain different facets of a very complicated disorder we continue to unravel. Despite this uncertainty about the precise nature of mental illness and how best to treat it, with the proper support, education and management plan, many people with schizophrenia can return to living normal lives. Openly communicating about mental illness, and being comfortable discussing it with our friends and family, can only help to dispel the stigma that can lead to late diagnoses and more difficult treatment. I hope this post has provided some insight into this condition, and I look forward to any feedback or corrections.

What are the chances of You?

Being alive is totally cool. There are a mind-bending number of  parameters that lead to what we call a life – the  millions of preceding generations of individuals pairing of with each other exactly as they did, as well as the specific pairing of one egg amongst thousands from the mother (over her lifetime) with one sperm amongst millions from the lucky male. And then you have to dodge the many misfortunes that can befall what is really nothing more than a dividing soap bubble with some protein inside – spontaneous abortion, genetic incompatibility with life, or indeed the whims of your maternal host &/or environment during gestation. And then, after all that, you might turn out to be a salmon. Pissed.

Or, if you go one extra astronomical bound of fortune, your bubble might have come from the genes of some organisms with a less depressing life cycle – pigs, dolphins, humans etc, some of which enjoy the pleasures of recreational sex, board games, and deep philosophical thought.

I could go into how great it is being a human at this point of our species’s history, what with the record setting life expectancies and awesome science, but unfortunately the geography of your birth still plays too much of a role to say that you wouldn’t necessarily have been better off thousands of years ago. Anyway, you get the point – You are alive, and a lot of things came together for you to end up reading this.

What are the chances?
Total and utter certainty, if determinism is to be believed.
The blind man throwing darts is a useful analogy. An observer exclaiming “what are the chances that you would hit in that exact spot?!” after the dart landed off the scoring section, and pierced the scrotum of a passerby would be deemed rather silly. Given that’s where it landed, the infinitesimal probability of the dart landing in any location, to the nearest atomic radius, suddenly disappears, and becomes ‘1’ – certainty.

The idea that one moment’s energies and velocities are the single result of the moment before it, is known as determinism, and some would argue is a natural extension of the basic principle of cause and effect. When taken to it’s logical conclusion, determinism suggests that every aspect of the ‘random’ chances that led to your existence were in fact inevitable from the moment of the Big Bang.
NB: Physicists get a bit shirty if you start talking about determinism – quantum physics doesn’t play very nicely with it. Still, it’s a nice idea 🙂

But who cares? You certainly exist, and you’re conscious, and there is no practical application for the idea of determinism except to write about in long awaited and rarely read blogs. So lets talk about You.

Psychiatry has kind of a thing about how our sense of identity is formed as an child. It talks about how we develop a sense of our place in the world, how we should cope with distress, and how we as entities exist in the minds of other people (usually our parents). When the normal framework for maintaining a stable sense of ‘self’ goes awry, all sorts of mental illnesses are said to result. You have been warned.

As a consciousness, we are not really the whole of our body – a person without hair, fingers or even legs has lost none of the hallmarks of what it is that sets us apart from the dreary life of a potato, cow or KCL student. Even if you look at the brain alone, we aren’t always being produced by it – when we are asleep our awareness is fractionated and variable, and when we’re physiologically unconscious it could be argued that we effectively stop existing. Even when awake, our nature can be transitionally altered by drugs, alcohol or pain. Clearly the notion that we are stable entities at the controls of a stable machine is untrue – learning, experiencing life (and making a mess of it) alters the biochemistry of the brain second by second. In turn, the consciousness that brain produces alters – perhaps following a new cascade or algorithm of thought in the short term, while in the longer term making a ‘mental note’ to not be brave about yoghurt use by dates . You exist in your exact state only once. With each passing moment ‘you’ (the balance of emotions, priorities and plans of an instant) become a blurred byte of memory that at least part of You are comprised of, and might later reflect upon with varying levels of affection, sympathy or distaste.


I hope to revisit sleep and dreams at a later point, but here is a brief crack at providing something interesting before I delve into exam season, and is the first piece I have written particularly for the purposes of this blog! Enjoy.

Almost every single organism we know of, from bacteria to blue whales has a some manner of circadian rhythm, and all of those with a brain have some manner of equivalent to sleeping.

While the simplest explanation for why we must sleep is that we become sleepy, sleep deprivation is eventually 100% fatal. A study into sleep deprivation in rodents was conducted, and within two weeks, every single subject died. When autopsies were conducted, nothing was found to be obviously wrong, except for the tell-tale signs of not breathing and zero blood pressure, commonly found in things that are not alive.

But beyond this perhaps ethically troubling experiment, a rare condition exists in humans by the name of fatal familial insomnia. It will come as no surprise to the more attentive reader that this too is invariably fatal, and is a condition caused by prion buildup in the brain leading to progressive deterioration of the ability to sleep. Death usually follows within 7 to 36 months of the onset of symptoms, which progresses from a state of partial insomnia leading to panic attacks and hallucinations, to total insomnia leading to dementia and death.

What is sleep? I think of myself as a consciousness generated by my own neuroanatomy, so when I am unconscious, to an extent you could argue that I no longer exist. You could use an analogy with the image produced on a computer screen as the conscious awareness produced y the unknown workings of a humming desktop computer. The screen will go into standby after a while, but the overall hum of the computer will not disappear entirely.

The analogy, while perhaps already a strain, ought not be taken much further. Computer screens will turn themselves off to prevent ‘burn in’, and while an interesting case could be made to apply this analogy to the mind, the reality is that scientists are still struggling to provide a definitive reason for why we need to sleep, or indeed point to the mechanisms through which insomnia causes immune suppression, depression, and even death.

Massive thank you to Mei Mac!!


So this website was set up on my behalf by the apparently tech savy Mei Mac, without my knowledge, permission or consent.
That being said….

It’s so cool! I’d been urged in the past by friends to get into blogging, but in her infinite wisdom, she was aware that I’d never get round to it without a kick up the bum. Now that my bum is sufficiently kicked, I’m really looking forward to musing about consciousness, and I’ll also be sharing any thoughts I have about developments in the neuroscience world.

I’ll probably take a while to get into the swing of this blogging business on account of exam stuff, and I hope to buck up the standard of my writing for anyone who enjoys what I blab about. So watch this space.

Mei definitely got one thing right.
Brains are fucking cool.

Representation and Memory

Written ‘a while back’, by Barney Low

When I saw a firetruck for the first time in my wild and misspent toddlerhood, there is a good chance that it was driving along without the siren blaring and lights flashing, nor indeed with any flaming building with billowing smoke in sight. Now however, when I think of the word firetruck, my mind immediately leaps to such images, perhaps with some offshoots into subjectively related concepts such as firemen, the battery of my fire alarm, or the f***ers who set off the fire alarms at unholy hours during my stay in my university’s halls of residence.

With the specific example of the firetruck, prior to this encounter I had probably developed a fairly extensive neuronal representation of what a firetruck might be associated with, having been a huge fan of ‘Fireman Sam’ as a child. If you had spoken the word ‘firetruck’ to me before the first time I saw one in real life, the pre-existing neuronal network linked to the auditory stimuli of the word would probably have had a few synaptic connections with the word ‘Sam’ and the visual image of his stop motion figurine, others might connect with sections of the brain associated with excitement, or the vague notion of sitting down to watch television.

As the real life vehicle drove past me for the first time, the basic visual stimuli to enter my eyes would be of a large, red, rectangular version of a car, driving along a road. It seems likely that I would have asked my Mum or Dad to confirm my suspicions; that I could store these novel stimuli under the neurone labelled ‘firetruck’. For the first time, a raw sensory exposure to this object of interest to me would be networked in, with links made to the colour, size, noise, and vehicular nature of the firetruck. At this point I think it is necessary to try and explain how the networking of the brain allows us to recall, at will, the image, sound, taste, emotional significance or functionality of an idea or object, and how this ability is intrinsically linked to perhaps the most significant difference between other animals and man – language.

For the sake of simplicity, I will try to explain the recall of long term memory with the example of a visual stimuli, but arguably the same principles apply to all kinds of recall. The human brain contains a lot of neurones, with some of the more conservative estimates guessing at around 86 billion, and with each neurone synapsing with an average of 7000 other neurones. When presented with an object, for instance an old teddy bear, the raw data  of light-dependent depolarization in the retina undergoes a great deal of processing before it enters the conscious field. There will be individual neurones that fire for almost every conceivable visual detail of an object; some that fire off when presented with a humanoid shape, others that fire off when presented with the particular colour of the bear, or indeed a lump of colour of a particular size or shade. Others still might fire in response to the specific pattern of light and shade that reveals the furry texture of the bear’s fur, or indeed the recognisable shape of most eyes we are exposed to. This pattern of firing would be preserved by one of the hallmark phrases of neuroscience – “neurones that fire together, wire together”, where a group of representory neurones that happen to be interconnected with most if not all of the stimuli, would strengthen their synaptic links with all of the lower echelon neurones, like the roots of a single bud.

The first time we saw the bear, we may have only had the word ‘teddy bear’ under which to label our furry friend, but having settled on a name such as ‘Louis’ or (I wasn’t a particularly imaginative child) ‘Panda’, that word would then have links back to all the various neurones that code for the different traits of that particular teddy. With language, we need only think the name of our childhood toy, and, without the original stimulus of the teddy in front of us, the neurone representing it would simultaneously fire off all the different sensory stimuli that had been activated alongside it in the past, as well as the stored representations of the bear’s texture, and emotional and sentimental significance.

The beauty of this system is that it allows each lower echelon neurone to fire off for many different objects, ideas or thoughts. A neurone that codes for circular shapes might fire off in response to anything from an apple to a clock, and would even fire off (though slightly less exuberently) when presented with the raw sensory data for a pear, far more than it would in response to a sock or a firetruck. It is by matching profiles of the firing (and indeed the specific frequency of firing) of many hundreds or thousands of neurones to a select few, higher echelon neurones, linked with others coding for verbal labelling and other associations, that we are able to so easily resubject ourselves to past experiences, thoughts and sensations at will, in ways that other animals have shown little evidence of being capable of. It also explains why the representation of individual concepts or ideas seems so diffuse when inspected using imaging techniques such as fMRIs, with the many hundreds of traits that make them up being spread broadly around the various sections of the brain.


Written ‘A while back’, by Barney Low

This was written a while back to try and summarize and present some concepts I was introduced to by an fascinating book on consciousness (Going Inside, by John McCrone). Please feel free to comment or correct.

Each instant of consciousness is the result of intense competition between the firing of neurones representing different facets of our mind, with some representing long term memories, objectives and desires, others the raw sensory input of the moment, and others still continuing to fire from the previous instant of consciousness. The thought, sensation or emotion that is potentiated is selected based on the frequency of its firing and its synergy with others that fired along with it, with neurones that fire for the abstract concept of a tree being more likely to fire off when preceded with the firing of subjectively linked ideas, such as forests or nature.

When the victor of this competition is pain, such as when we tread on a pin whilst dancing in our pyjamas, that instant of consciousness will be dominated almost completely by a redirecting of awareness to the overriding stimulus: making us aware of the noxious stimuli, diverting our gaze to the source of the pain as reported by our proprioception, and alerting us to the fact that we have instinctively pulled our foot away.

If we are aware of incoming pain, such as when we are given an injection by a doctor, our mind is primed to suppress the reflex withdrawal and perhaps even anger that would normally result from the sensory stimuli we are subjected to. Here is an example of where the higher cognitive levels of the frontal lobes associated with planning might become involved, interacting and modulating the more primal and reflex orientated aspects of our brain’s functions in preparation for the instants to come. We might even be able to continue a stream of verbal or internal dialogue with our friendly doctor (or our disgruntled complaining self); ensuring by concentrating and the suppression of other input, that the chain of neuronal firing responsible for producing logical sentences is not interrupted from one instant to the next.

This continuity is an essential feature of our conscious experience, with our more recently active (or generated) neuronal networks firing off with greater frequency than less relevant neurones, which might for example represent our mind’s map of our primary school or the visual stimuli of a long lost toy. Examples of this continuity in action would be the continual firing of a neurone representing anything from the earlier content (or the general gist) of a friend’s tale as they expand into gory details, to recalling which seat at the dinner table is our own. This form of recall is essentially what is known as ‘working memory’, and I will go on to discuss how the brain might be able to potentiate the raw content of a moment in a more long term form in another spiel.

Published in Pi Magazine: The Stuff of Thought

Published in Pi Magazine: The Stuff of Thought

Published on 2nd March 2013 in Pi Magazine. It’s basically a rehash of the ‘Consciousness’ and ‘Representation and Memory’ spiels, so if you’ve seen them, then maybe give it a miss. Alternatively, if you’d prefer a condensed summary of the two, then go right ahead!

Click on the link above to read the article online.

The Stuff of Thought. By Barney Low