Deji Ijishakin

The self-styled Philosopher King, Deji is a multi-talented Neuroscientist with interests in the bridge between neuroscience, computing and theoretical physics. Starting on Deji’s interests in his field, our conversation soon turned to theoretical neuroscience and consciousness, all without an old white man in sight…

What are you up to at the moment?

Right now I’ve just finished my exams, which is a massive release. Other than that, just working on my music, I’ve got a song coming out Momento Mouri, which I’m releasing on my birthday.

My masters is going good, I’m basically two thirds of the way, the only thing I’ve got left is my dissertation. I focused on neuroimaging for one third of my degree, which is a class of techniques to get images of the brain. There’s different ways to do it… most people have heard of MRI but there are loads of other ways to do it, its all super interesting stuff and I’m sure it will be useful for the future.

So what’s the plan for the future then?

For my project I’m going to be analysing brain data from people who have taken LSD and DMT, and doing some machine learning analysis and computational modelling on the info.

Hopefully afterwards I’ll find work as a research assistant and then potentially do a PhD, we’ll see how things go.

How did you get into neuroscience in the first place?

My bachelors was in sociology and psychology, my Uni journey is pretty jokes. I’ve always been into philosophy so that was what I originally aimed to study and I originally got into UCL for it, but I was always that kid to didn’t work hard enough but just coasted by and I didn’t end up getting the grades to actually go there. I didn’t even know what I was thinking but my sister was just like “Study something..just go to Uni”, so I ended up doing a criminology course at Kent, to be honest I couldn’t even tell you what criminology was about when I started there other than what the name suggests.

I met a couple people at Uni who were doing psychology and it looked tempting… I had spent the summer before watching all these Darren Brown videos and thought this was what doing psychology could lead to! So I switched and when I started learning more about psychology and it’s basis…the Brain. By my second year I was really getting into neuroscience, reading all the popular books and decided that’s what I was going to do in my life.

It’s interesting because although my journey hasn’t been very typical, every time I reach I different step in education I uncover a bit more about what I really want to do. From philosophy to philosophy of the mind to psychology to neuroscience… and now theoretical neuroscience. It was a natural progression.

Yeah I feel like although they’re different subjects they all lead into each other nicely. Looking at the brain… how it works, then you get into consciousness and the Hard Problem, it all makes sense.

What’s messed up with our educational system though is the fact that you have to almost decided what you want to do in life when you’re taking your GCSE’s…

I completely agree, if you want to do a specialist subject at Uni you could have to make the decision at 16-years old!

Although there are merits to the system because I was able to switch around. My A-levels were very much humanities-based and I didn’t really know what science was. So I’m very grateful that I was able to cross over into the world of science.

I feel like that’s more of a merit to you though, rather than how easy it is. I doubt the average person would be able to seamlessly switch from humanities to neuroscience. Like you said you read loads of literature and did your own research and hustle…. hats off to you.

To be honest I wouldn’t even see it as work. That’s the beauty of when you’re really passionate about something, it’s almost as if its not you doing the reading or you doing the work… you just do it, you’re almost a passive observer.

I had this in an exam recently, I was just really enjoying it to the point where I was almost watching myself do it.

I know what you mean, I wouldn’t class doing physics as work per se. Slyly I’d get enjoyment out of revising and even doing exams. Obviously if it’s a hard exam and you’re doing shit it’s a different story…. But I know that feeling.

So what is the biggest thing you’re interested in neuroscience right now?

I’m really into something called the Free Energy Principle. It’s a Bayesian Brian Hypothesis (Bayes theorem is a way of calculating conditional probability… Such as the probability of a patient having liver disease on the condition that they are an alcoholic).

It basically states that the way the brain is constantly updating is by using Bayes Rule, literally plugging in your prior beliefs into to this theorem to achieve a prediction. This is the most fundamental thing the brain does, from the level of Am I looking at a phone right now? To the level of Should I apply for a PhD?

How would you even go about investigating something like that?

This is why it’s such a hot topic and why some people are against it. The reason why it is true is not because of experimental evidence, it’s because of it’s mathematical soundness. The reason why people assume the brain is doing Bayesian inference (the brain uses bayes theorem to update the probability of a hypothesis as more evidence comes in… eg. You see a cat, then you smell cat shit, then there’s some brown stuff on your bed.. the brain will be using bayes theorem to continuously update the likelihood that said cat has shat on your bed), is because it’s the most mathematically simple way to describe what’s going on.

So this is obviously a highly theoretical description of how the brain works… How does this translate into an explanation into how the brain actual does that? From my limited knowledge I know that lots of processes in the brain aren’t even well understood.

This almost treats the brain as a computing machine, how does this theoretical model cope with the fact that some people are able to predict things better than other people, or variations in intelligence and understanding of the world?

The way that the Bayesian inference occurs is through different synaptic connections (the junctions that connect neurons, cells which use electrical impulses and chemical signals to transmit info around the brain). By strengthening or weakening these synaptic connections the brain updates prior information to obtain a prediction. Under this framework “Intelligence” would be your brain’s ability to alter these connections in order to adjust your prior beliefs in the most logical way. Everyone has variations in brain anatomy, which would affect their ability to update their prior beliefs to form a sensible prediction.

This could also account mental health disorders like schizophrenia, in this framework someone with schizophrenia would not have strong prior beliefs. An example would be auditory hallucinations, someone with strong prior beliefs would determine that a voice in their head is actually them, whereas someone with schizophrenia could determine that this “voice” is actually someone or something else (N: I tried to imagine a situation where my mind is wiped. If I then saw a plane, my lack of strong prior beliefs could lead me to infer that the plane was actually a flying monster which would soon eject cats to shit on my bed).

The other side of the spectrum is something like depression, instead of the problem of not having strong prior beliefs, it’s that your prior beliefs are too strong. Your depressing thoughts of worthlessness and sadness are then constraining the way you view evidence way more than the should. It’s interesting because there are studies that show that depressed individuals actually have a more accurate view of reality. Now let’s look at how psychedelics are used as a treatment for depression. It increases the entropy of the brain, the amount of different states a brain can be in. This means that the depressive priors are being diluted by the increase of different states, when people say the have a “new view of life” after taking psychedelics, they are literally using different synaptic connections to make predictions.

That’s actually mad, I’ve never heard it be explained like that before. But how do you conduct boots on the ground research into this?

For my dissertation I will be taking brain data from people taking LSD and DMT, I would then measure the entropy of the brain. Looking at the connectivity patterns between different regions of the brain, people who have taken psychedelics should have a much wider array of communication patterns between different regions, which implies that the number of micro-states the brain can be in has increased (another way of saying entropy has increased).

I think the beauty is that compared to other disciplines neuroscience is so young, we don’t know how far we can push the theoretical side of it, we’ve just started! When you compare it to theoretical physicists who can make predictions which take decades for experiments to prove (e.g. Einsteins gravitational wave), we haven’t reached that stage with neuroscience yet and I’m excited to see what happens.

But is comparing neuroscience with physics the right way? Once you get to a biological system like the brain, do we have the ability to predict and model things by boiling down to fundamental mathematics? I can use a computer to model some particles moving around in a box, but how can I model something so impossibly complex as the brain?

I don’t think so. It’s like any other science, we can’t see the answers until we get there, we can’t compute something….until we can. If you had asked James Maxwell about Quantum Mechanics he would have been baffled! We’re in a similar situation now with neuroscience, we’re limited by the technology, it takes time.

And you don’t have to go to a fine-grain approach as particles, instead you could use molecules or chemicals as the fundamental “unit” and just treat the brain as a chemical soup. As you said,

sometimes it’s easier to use statistical methods when faced with modelling a large collection of particles. I think with time things will get better and I feel super-interested in pursuing it, there’s so much more things to learn and I can’t wait

If we were eventually able to mathematical model everything that’s going on in the brain, would we then be able to essentially re-create a human mind on a computer?

I think there’s two elements to it. There’s the element of you being able to reproduce the human brain within a computer, using fundamental Axioms (established truth) which describe how the brain works. Then there’s being able to individually map someone’s neurological make-up and “upload” that to a computer.

I think we’re mostly likely to get to the first one, understand the fundamentals of the brain and how consciousness pops out as the end result.

I’m a materialist, I believe we’re made out of matter and there’s not some magic thing that’s going on behind the scenes.

BUT.. consciousness is immaterial, it’s abstract, there’s not one place or time where you can say consciousness Is. You can say you are conscious in this moment in this body, but consciousness itself is not in one particular place, or else you could break it down into composite parts, and you can’t.

How does consciousness come into play when looking at the Many Worlds Interpretation? (this interpretation of Quantum Mechanics implies that all possible outcomes of a quantum measurement are realised in countless other “worlds” or universes, in one world the cat shits on my bed, in another it shits on my sofa)

To be honest that is a problem hahaha, I’m not sure!! I guess I’m going to say that right now I don’t see any way of proving or disproving the interpretation using experiment, so let’s cross that bridge when we get to it!

Consciousness is the result of evolution across millions or billions of years, we don’t have that time! We’ve only got one lifetime each to work on it. Obviously you can pass on the baton and share knowledge and information, but maybe there just isn’t enough batons…