Schizophrenia

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 brief post has provided some insight into this condition, and I look forward to any feedback or corrections.

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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.

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.

Consciousness

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

stuffofthought