People have been fascinated by the mysteries of the human mind since time immemorial. For centuries we tried to figure out which parts of the brain were home to a person's ego. Scientists today know that things are far more complicated than that, yet the mystery remains. Professor Milan Brázdil, a neurologist at the MU Faculty of Medicine, would like to get to the bottom of how the brain functions.
And he really is succeeding in pushing out the boundaries of knowledge. An epileptologist of some renown, his discovery of last year made an international impact. He revealed the secret of the phenomenon of déjà vu, the elusive sensation that we are looking at something that we have seen some time in the past, although simultaneously we suspect that this is not true. Thanks to this discovery, this April Brázdil became the first recipient of the G.J. Mendel Prize, which is conferred by Masaryk University as part of the new Programme in Support of Research.
Brázdil, who works as a head researcher at Ceitec and is head of the Department of Neurology at the university hospital, considers the revealing of secrets of the brain to be a great adventure. He paraphrases the famous theorem by Gödel which claims that no system is able to comprehend itself fully. “And our brain – that's what we are," he adds.
Have you ever experienced déjà vu?
It is said that 80 per cent of healthy individuals have this experience at least once in life, and, yes, I've had it repeatedly. It seems it occurs most commonly between the ages of eighteen and twenty, which is borne out by my own experience. Frequency gradually decreases with age. I can no longer remember exactly when I last experienced déjà vu.
Your main professional interest is epilepsy? How does this relate to déjà vu?
Quite closely. We know that up to 30 per cent of patients with temporal lobe epilepsy experience at the beginning of an epileptic seizure, as the first clinical symptom, the sensation of having seen something before. In such instances we understand the connection. But in healthy people it remains a mystery. There is a whole range of hypotheses, from the absurd parapsychological to ones orientated towards neuroscience.
How did you approach the problem in your research?
We told ourselves that there must be some connection between pathological and normal déjà vu. We know that in patients with epilepsy it is caused by disruption in the neural network, in which a crucial role is played by structures on the inside of the temporal lobe – to be specific, the component known as the hippocampus, which is responsible for memory and the creation of memory traces. During the preoperative examination of patients, when we try to locate the epileptic focus, we can even induce déjà vu artificially by stimulating this component of the brain.
So you have proven that déjà vu is associated with the hippocampus.
That could have been expected. But thanks to research we carried out on healthy volunteers, we have shown that the hippocampus is statistically considerably smaller in those who know the sensation of déjà vu than in those who have never experienced it. It has even been shown that the smaller the hippocampus, the more frequent the occurrence of déjà vu. We are almost certain that the answer must be somewhere there. The question is, what does the proportion tell us?
Do you have any hypotheses?
Let's put it in a broader context. The hippocampus is a specific part of the brain in which new nerve cells are created throughout a person's life. This is something that we haven't known for very long. Earlier it was assumed that a person was born with a finite number of nerve cells, which died off as he or she got older. This is not so. It is in the hippocampus that more and more new neurons are formed. This makes this part of the brain very sensitive, vulnerable, and susceptible to various influences from the external environment. A brain which at toddler age suffers an inflammation or comes under psychological stress may as a result have a hippocampus of reduced size. We know this from our study of animals – the smaller their hippocampus, the more excitable they are. We assume that this is similar with humans – for various reasons, most of us have a hippocampus of reduced size, making it more sensitive to irritation, causing us to experience déjà vu.
What irritates the hippocampus?
The brain is an extremely complex structure in which a wide range of electrical discharges occur. Indeed, this is its operating principle. Inevitably, however, there are occasional discharges that are defective and out of place. There exist mechanisms that should prevent them from spreading to other structures, but apparently these mechanisms are not perfect either: sometimes a defect sneaks through, and if the discharge reaches the sensitive hippocampus we feel something strange and uncanny, and this makes us anxious.
Has your research into déjà vu pushed you in the direction of the treatment of epilepsy?
I wouldn't say that the impact was direct; this is actually basic research in neuroscience. However, in future a better understanding of how the hippocampus works will be very important, not only for the diagnosis or treatment of epilepsy of the temporal lobe but also for other neurological and psychiatric illnesses that are associated with these structures. These include Alzheimer's disease, where for some reason the hippocampus suffers degenerative damage and an increase in the rate at which neurons die off.
Epilepsy is your main scientific interest. Is it still a mystery for medicine?
Yes, and it will continue to be. Gödel's theorem states quite clearly that no system is able to comprehend itself fully. We are our brain. Our thinking is related to the functioning of our brain. Therefore we will never know it fully. It is so complex that we will continue to reach a certain level and strive to penetrate to the next. From the system to the cell, then to the molecule and beyond – there remain many more levels we know very little or nothing at all about. We suspect that epilepsy is caused by there being too many or too few transmitters of nerve signals in certain parts of the brain. But what is there beyond this? And beyond that? Why is it there? It's truly fascinating.
It is said that epilepsy is the neurological disease we have known about the longest. How is this so?
We know that epilepsy is with a person from the very beginning of life because it is accompanied by a great seizure, which used to be known as grand mal – a great evil. This dramatic symptom is a very powerful experience for all who encounter it. Naturally it is frightening for the layman. We know the disease from the Gospel of St Luke, ancient Egyptian hieroglyphs, the Akkadian language and Hippocrates's treatise De morbus sacer; in the Middle Ages it was known as morbus demoniacus.
It is fascinating to hear you talk about it. How did you actually come to be interested in epileptology?
I was first attracted to the brain while I was still a student. To begin with, I thought about pursuing neurosurgery. I finished my studies in 1989, just before the Revolution, and I had no desire to become politically involved. In any case, it was clear that that would not work out. After my exam in Neurology the head of the hospital department offered me the chance to do research there. So the attraction grew, and after I graduated from the Faculty of Medicine I joined the department. After my postgraduate studies I began to specialize in electroencephalography – the method by which electrical activity is recorded along the scalp. There is some relation between this and epileptology, which I have been involved with more and more intensively since the 1990s. In the meantime our department has become the most important in this field in the Czech Republic.
In addition to this you work as a researcher for Ceitec MU. In which role do you feel most comfortable, that of researcher or that of physician?
If I was able to tell you that, then perhaps today I'd be more one than the other. I must admit that I'm happy to be able to do both. It's not altogether common to divide one's attention between patients and research, and perhaps it's not ideal, but quite simply I'm not able to choose.
Why not?
I'm attracted to both of them, for a variety of reasons. The appeal of clinical medicine is in its great importance. It's difficult to put into words how it feels to give help to someone who really needs it. At the same time I have a very inquiring mind – perhaps too inquiring. I like to find out how things work. In 1992, immediately after my postgraduate studies, I went straight into further study. The first phase of this was research into epilepsy, after which I gradually got down to the basics of how the brain functions. I began to ask myself how and why, and my research became a game which is still a source of great enjoyment to me today. So now if I was forced to choose a single path, that choice would be really hard to make.
You suggest that the combination is less than ideal, but might not the opposite be true? After all, your patients are treated by a person who is directly involved in pushing out the boundaries of knowledge.
There's certainly something in that. It's not always good to close yourself off and focus on a single topic, as medicine and research sometimes have a tendency to do. As there is ever more information and we are overwhelmed by it, we are very selective in our interests. In the field of epileptology alone, five professional journals are published every month. It's getting so that it's impossible to read them all, not least if you follow other, related fields. For this reason I'm glad that I'm active in both research and medicine; this allows me a more open view.
Although you are fascinated by research, you say yourself that we can never properly know ourselves...
But our every step is an adventure and a challenge!
Do you have a goal? Something that you would really like to ascertain or discover?
I don't dare set myself a single, basic goal. The journey itself is the goal. Scientists are presented over and over again with new horizons. And that's what it's like with déjà vu. We have some hypotheses, which we will disprove or verify, and later we will have other hypotheses. For me it is a great challenge to develop what we know in the field of social neuroscience.
Please tell me more.
We used to have a tendency to investigate the functioning of the brain by looking at what went on inside it under certain stimuli. But we didn't look at how it worked in certain social contexts. We didn't look at what went on during communication, be it verbal or non-verbal, or during economic decision-making, or during irrational behaviour. Today neuroscientists have instruments that can get to the bottom of these things, but still it is necessary to cooperate with other disciplines and find common ground. And that is far from easy.
Perhaps my question is a little too spiritual, but is it realistic to describe things relating to the human mind by investigating the brain?
In my understanding, there is no doubt that the mind is related to the working of the brain. It is somehow possible to grasp the individual components of the mind with reference to the brain; they can be associated with certain structures and networks or the communication between them. Of course it is pointless to search in the brain for the centre of consciousness or the site of the soul. But there is no doubt that the key to what we are like in terms of our character, let's say, is to be found in our brain, and I believe that the workings of neural networks give the basis for whether a person is of choleric or phlegmatic temperament, for instance. We are now able to track a number of similar things. Others remain beyond us because, in my opinion, our instruments remain too crude. On an archaeological site, you are not going to find an antique clasp with an excavator.