Portal de Periódicos da CAPES

Michael Land

2005; Elsevier BV; Volume: 15; Issue: 8 Linguagem: Inglês

10.1016/j.cub.2005.04.014

1879-0445

Michael F. Land,

Neurobiology and Insect Physiology Research

Michael Land is Professor of Neurobiology at Sussex University. He has studied the eyes and vision of a wide variety of animals, and has written a book, Animal Eyes, with Dan-Eric Nilsson. More recently his work has mainly been concerned with the relations between human eye movements and the control of actions. What got you started in science? It had to be a lot to do with the teachers I had at school. The physics and biology teaching was terrific and the chemistry indifferent. I think this combination pre-adapted me for looking at things like the workings of strange eyes, and away from the molecular biology that was then exciting others. At Cambridge I developed an almost Victorian passion for invertebrates, largely because of the superb lectures of Carl Pantin, who managed to combine the taxonomy, physiology and ecology of each group in an inspired way. The colossal scale of evolution began to dawn on me too — and the realization that the vertebrates are only a small corner of the big picture. During the first year of my PhD at University College London I had a stroke of luck. I looked into one of the 60 eyes of a scallop — the animal I was working on for reasons unrelated to vision — and saw an upside down image of myself. It dawned on me that something was wrong: the image was too bright and, as I was looking at it through the lens, it should have been near infinity and not actually in the eye. The answer turned out to be that this is almost the only example in nature of an eye that uses a concave mirror rather than a lens to form an image. My first real ‘aha’ moment. I’ve had three or four since, but that was the first and the sweetest. What papers have most influenced you? Different papers have affected me at different stages in my career. The nice thing about the comparative work on eyes was that I got to experience the beauty of some of the papers from the late 19th and early 20th century, especially those of Grenacher and Hesse. The quality and subtlety of the coloured lithographs in those papers is breathtaking. They must have cost a fortune to produce. Later, as I got more interested in behaviour, a review by Horst Mittelstaedt ‘Control systems of orientation in insects’ (1962, Annu. Rev. Entom. 7, 177-198) introduced a clear framework for thinking about the role of feedback and other systems ideas in the organization of behaviour. My current work on eye movements was certainly inspired by one picture in the book by Alfred Yarbus (1967, Eye Movements and Vision. New York; Plenum). The picture is of a painting ‘The Unexpected Visitor’, representing the return of a man to a family, with the eye movements of a viewer superimposed. The clever thing Yarbus did was to ask his viewer different questions about the picture — for example, “estimate how long the visitor had been away from the family” — and for each question he got a quite different pattern of eye movements, each clearly related to that particular question. This was the first clear demonstration that eye movements are not just reflexive movements to prominent features in the surroundings, but are related to the viewer’s thoughts. This seems obvious now, but it wasn’t then. Figure 1 Why did you switch from invertebrate eyes to human eye movements? It wasn’t that much of a change. I’d worked on eye movements of spiders, flies and mantis shrimps before, so I was really only extending my range of animals. Besides, it was nice to work on an animal you could actually talk to. More seriously, although eye movement recordings had been made for almost a century, up until about 1990 there was very little work on the eye movement strategies used by people doing ordinary things — walking, driving, preparing food, playing games and so on. There really wasn’t a Natural History of eye movements. About that time, wearable eye trackers became available, and there was an obvious niche to fill. It was interesting coming to the field from zoology, because eye movement research had mainly been the province of psychologists and physiologists, both of whom like their experimental conditions to be tightly controlled. Experimental psychologists in particular are trained to be fiercely Popperian, removing all confounding variables and setting up refutable hypotheses. Uncontrolled observation isn’t an option. The ethological tradition that I came from could be experimental, but involved minimal disturbance of either behaviour or environment. As Niko Tinbergen pointed out, life throws up its own experimental situations. The trick is to spot the regularities in what at first appears to be the chaotic continuum of natural behaviour. Things have got better recently: psychologists now approvingly use the expression ‘ecologically valid’ for studies that have something to do with real life. But for some in funding bodies, ‘curiosity driven’ is still an expression of disapproval. I think it is worth recalling that Darwin spent many years of curious observation before coming up with his big hypothesis. What is the best advice you’ve been given? When I was working at Plymouth on reflecting structures with the great marine biologist Eric Denton, we got a nice result one day. He said that when you have a good result you should have a good dinner. That way, when you fail to repeat it next day, at least you’ve had a good dinner. I also remember J.Z. Young’s dictum — never write anything you can only publish once. Do you have views on the funding of science? I have always done ‘small’ science. Bugs and humans are both cheap, compared with cats and monkeys; and I like to do my own work, or else collaborate. So I’m cheap to run. It has always struck me as ridiculous that the process of getting £25K for some kit and a little assistance is as difficult as getting £250K or more. I have argued that research councils should ring-fence pots of money for different sizes of grant, but I have the feeling that it is seen as just too much trouble to administer small grants. Being ‘good value for money’ in terms of papers per pound does not make you popular with universities either. They just want the overhead that comes from you becoming a large employer. As I approach what I hope will be an active retirement the opportunities for finding the small amounts of money I will need diminish further. Universities had that sort of petty cash once, now they don’t. It would be good if someone would address the needs of wrinklies who won’t go quietly. What are the future directions of your field? I think it not impossible that within a decade or so we may have a reasonable idea of what a thought looks like in terms of neural activity. No one technique can provide this but advances in scanning technology, single and multi-cell neurophysiology and other more exotic electrophysiological techniques may crack it. Eye movements recording can help by providing observable manifestations of thought processes. Modelling may help too, but I’ve not been impressed so far. Sherrington imagined the nervous system as an ‘enchanted loom’. It would be good to see his dream come true.