Portal de Periódicos da CAPES

Q & A

2004; Elsevier BV; Volume: 14; Issue: 16 Linguagem: Inglês

10.1016/j.cub.2004.08.002

1879-0445

Martin Heisenberg,

Plant and Biological Electrophysiology Studies

Martin Heisenberg is Professor of Biology at the University of Würzburg and Head of the Department of Genetics and Neurobiology. Since 1968 he has investigated brain and behaviour in Drosophila, trying to make use of genetics in neuroethology. His early studies of the fly visual system are summarized in a book 'Vision in Drosophila' (1984; with R. Wolf). He currently focuses on visual pattern recognition, the localization of memory traces, the role of initiating activity in operant conditioning, selective attention, and motivation. He plays the flute, likes hiking in the mountains and writes about the impact of the biological sciences on society. He is the son of the physicist Werner Heisenberg (famous for the uncertainty principle of quantum theory). What got you interested in brain research? At 17, I had the chance to participate in some of the legendary mind–body seminars at the Max Planck Institute of Behavioural Physiology at Seewiesen. Once, in 1957 or 1958, the philosopher and physicist Carl Friedrich von Weizsäcker was a guest speaker. In the audience were Erich von Holst, Konrad Lorenz and about 30 others, crowded into a little seminar room. Weizsäcker's topic was the meaning of quantum mechanics for brain research. He tried to explain why it did not make sense to think of an electron as existing independently of the observer. Lorenz did not like Weizsäcker's view and tried, again and again, to offer less radical conclusions, but Weizsäcker refuted each one of them. By the end Lorenz was in a rage, declared further discussions futile and rushed out of the room, slamming the door behind him. Dead silence followed. Eventually someone was sent after him to get him back to the session. I was thrilled by all this commotion realizing that some scientific questions were close to our most existential beliefs and that it would be worthwhile to be concerned with such issues for a lifetime. Who had the most influence on your scientific education? Outside of my family, probably Max Delbrück. I worked with him as a postdoc. He had left Germany for the United States just before the 2nd World War and was then back on sabbatical in Cologne where he had just helped found the well known Genetics Institute in Cologne, an attempt to bring excellent research to German universities. How did you get to work with Delbrück? A friend suggested I ask Delbrück where one could do brain research in the States. When I called, Delbrück thought a moment and said: "Well, it is not quite brain research, but why don't you work with us?". I had a great time with him. He had three good lessons. First, science must be fun. Second, do not tell me anything I should keep secret. And third, keep asking until you have understood or know that a proper answer can presently not be given. (Delbrück exercised this principle even in public seminars with large audiences, which caused obvious problems.) And the influence of your family? This is more difficult to say. I guess your way of thinking must be rooted to some extent in the environment of your childhood. We were seven children and it was largely my mother who was in charge of our upbringing. My father contributed fun and games, but otherwise got involved in our education only if something important was at stake. For instance, if our performance at school dropped way below acceptable limits, he had stories of general wisdom like "From nothing comes nothing", or by analogy with a vending machine "To get out a candy, you better put in a coin." I remember only few occasions in which I had my father for myself; on one of these he told me about the meaning of science. He explained that science takes place and is rooted in the human language (of which mathematics is a part). The language into which we are born is part of our culture. There is nothing to escape this fundamental condition. Even terms such as 'nature' or 'reality' have changed their meaning in the course of history. Is it difficult having a famous father? It is a great privilege to have a father with a lucid mind whom one can love, one who is still vividly present in one's mind a whole generation after he passed away. What is difficult to bear is the recent public debate which has distorted his personality as much as history. Is there a central goal in brain science? Evidently, understanding the brain. You will find two opposing attitudes towards this question. Some say it is already answered and we have just to fill in the details. Others feel, as I do, that the most basic operating scheme is still obscure. Perhaps the machine concept is leading us astray. Our unformalized models of the brain disregard the autonomy of organisms. But there is abundant evidence for this autonomy. Dreams and hallucinations provide us with vivid experiences from 'within'. Or take electrical stimulation: how else but through a process of self-organization could a local, uncoordinated neural activation lead to meaningful behaviour and rich experiences. Equally impressive is the recent success of stem cell implants in the adult rat brain after experimental stroke, leading to an improvement of cognitive behaviour. The real brain model will be built around its self-organizing powers. Life permanently confronts us with genuinely new situations. Thus, behaviour must be creative to have success. This means to decide, take the initiative and try things out. Such properties of brains can only be derived from autonomy. I still hope to see a basic behavioural model of the brain being developed. What made you work with flies? I studied chemistry, then switched to viruses and bacteria, then to a fungus in Delbrück's lab. I was in the midst of molecular biology which was great fun. But at some point I realized that it was not brain research. At that time Drosophila with its potent genetics was just about to go molecular. And flies have brains. I hoped for a while that I could understand fly brains just as chemists understand their molecules. I was still young, I was determined not to get trapped by the mind–body problem. Do flies have feelings and a world model? I soon realized that, even with the smallest animal, studies of brain function can not avoid the mind–body problem. I started out with the visual system. Does a fly see? If so, what does it see? Infinite confusion. But you asked about feelings: we have access to the feelings of our fellow humans primarily by empathy. We assume others feel like us. This sharpens our perception of the differences and uniqueness of the other. With animals the empathy approach does not fully work. They are just too different. But what – if anything – of what we know about human feelings applies to flies? Science treats these 'mind questions' always in the same manner: we first have to establish a catalogue of objective criteria going along with our own feelings. (Just to have the feelings is not enough.) With this catalogue we are then in the position to investigate which of the criteria also apply to the fly. Finally, we have to decide whether to call it the same or not. But do not forget, we are talking about criteria accompanying the feelings, not the feelings themselves. You still haven't answered the question! Flies show signs of pain and avoid the smell of dead flies (as if they had fear); they fight with other flies and their courtship is motivationally regulated. For the other mental phenomenon you mentioned, the experience of a 'world model', a catalogue of objective criteria has yet to be worked out.