СÀ¶ÊÓƵ

Sensory Systems at СÀ¶ÊÓƵ

Professor Mike Land, FRS

I came to СÀ¶ÊÓƵ in 1971 on a temporary lectureship, partly because of its radical chic reputation, but mainly because of the quality, and quantity, of the faculty working in my field of sensory biology. There were three distinct strands. In Experimental Psychology, Stuart Sutherland was building a vision group which would include Pete Lennie, Mark Georgeson, Bill Muntz and Keith Oatley, and later George Mather, and a hearing group centred around Chris Darwin. Attached to Experimental Psychology, was a Medical Research Council Unit led by Herbert Dartnall, famous for his studies of visual pigments. This included Aubrey Knowles, Jim Bowmaker, John Lythgoe, and Graham Martin. And in Biology itself Richard Andrew’s group included Tom Collett and Fred Miles, then on leave at the National Institutes of Health in Washington, and for whom I was the temporary replacement. At the same time that I arrived, so did Ian Russell, who over the next three decades built up a hearing group acknowledged as one of the most successful in the world.

The various vision strands had a lot in common, often to do with the animals involved. Stuart Sutherland had worked with J. Z. Young on Octopus in Naples, and his ideas on their pattern recognition mechanisms were ingenious. By the time I came, he had given up research in favour of writing rather good book reviews, and later his self-reflective book on depression, Breakdown. He also wrote a book on animal discrimination learning with Nick Mackintosh. Bill Muntz, a tall congenial man with an enviable air of modest self-confidence, had worked on vision in amphibians and fish, and later on that most enigmatic of creatures, Nautilus. Bill, after a spell as Subject Chair, went to Stirling and then to Melbourne. Graham Martin studied owls, and had a spooky room where the birds caught things.

Fred Miles stayed at NIH, for which I remain grateful because my job became permanent. Tom Collett and I teamed up for a few years in the 1970s, trying to make sense of the aerial gymnastics of flies (our motivation for this was partly that an over-funded Max-Planck group in Tübingen were getting it all wrong). Tom subsequently moved to work on navigation in bees and ants – and this excellent work still continues. I returned to studies of animal optics in shrimps, spiders, butterflies, and even snakes. As one strand of this work, I was excited to discover that shrimps had evolved an optical system based on mirrors, which I described in a Scientific American article in 1978. This inspired an astronomer, Roger Angel, to propose this biological mechanism as a design for an X-ray telescope, which was later developed at the Universities of Leicester and Melbourne. There were even plans to put this telescope into space ... but funding ran out. No matter, I was still chuffed that biology could metamorphose into an engineering application.

In about 1990, I changed course to work on the role of eye movements – human this time – in guiding our actions in everyday life. This work was greatly helped by a collaboration with Jenny Rusted, a proper psychologist with the background I lacked in a new field. Daniel Osorio joined the Biology group in 1992, again from a background in insect vision, and has become a leader in the field of colour vision. He and Richard Andrew devised an ingenious technique involving small cones of patterned paper containing hidden seeds to study colour vision in young chicks.

Visual psychophysics, which teases apart the different mechanisms that contribute to human vision, has also had a distinguished life at СÀ¶ÊÓƵ. Mark Georgeson, who was at СÀ¶ÊÓƵ until 1976, studied the way the brain filters information from the retinal image to build up representations of edges and ultimately features. He also collaborated with Mike Harris, an early СÀ¶ÊÓƵ neurobiology student and former rock musician, on aspects of motion perception. George Mather, who came to СÀ¶ÊÓƵ in 1984, continued this tradition with studies of motion perception, and the effects of blur as an image-depth cue. His more headline-catching research, however, was a study of the uncertainty of line calls in professional tennis which showed that line-judges are indeed more reliable than players. Curiously, he found that the motion of the ball’s image does not itself seem to cause errors.

Hearing studies at СÀ¶ÊÓƵ followed two routes. Chris Darwin was an acoustic psychophysicist, and appropriately an excellent violin player. His particular interest was in the way we localise sounds in space using their phase and amplitude. I remember with pleasure his inaugural lecture when he encouraged Stuart Sutherland to inhale helium, and emit uncharacteristic high-pitched whinnies. In 1974 Chris was joined by another musician, Christopher Longuet-Higgins, who had already had a distinguished career as a theoretical chemist before turning to cognitive psychology. His work at СÀ¶ÊÓƵ involved not only music analysis, but also language understanding and visual-scene analysis, before his final retirement in 1988.

Ian Russell originally worked on the lateral line organs of fish, structures related to the ear and responsible for detecting displacement waves in water. In 1975, Pete Sellick joined him. They decided to apply the same techniques of intracellular recording to the cochlea of the ear itself, mostly using borrowed kit. They had no grant because the Science Research Council had decided that it was impossible to record from cochlear hair cells. Despite this, in 1977 they published their classic Nature paper on the tuning properties of cochlear hair cells. There’s a moral here somewhere. After this Ian was joined by Jonathan Ashmore, who had studied neurobiology at СÀ¶ÊÓƵ; they discovered that when they injected current into hair cells the results didn’t make sense. Subsequently Ashmore found that the reason for this was that the cells were actually changing shape. This was the beginning of a study of the way that hair cells act as mechanical amplifiers which refine the tuning properties of the cochlea. Guy Richardson, another undergraduate from the neurobiology course in the 1970s, returned to СÀ¶ÊÓƵ where he developed organ cultures of the cochlea to enable direct physiological studies on hair cells. He went on to develop ways of using genetic techniques to analyse the molecular structure of the various components of the system. There’s promising medical application here; these studies on the molecular composition of the tectorial membrane have led to the identification of mutations in TECTA (a gene encoding a large matrix molecule expressed in the inner ear) as a cause of both stable and progressive forms of human hereditary deafness. Such knowledge now allows (with gene chips and Next Generation sequencing technology) the diagnosis of one form of genetic deafness and the identification of carriers of such deafness-causing mutations.

Meanwhile, Corné Kros had joined the group and won a Royal Society Research Fellowship to work on mechano-electrical transduction in the cochlea. André Lukashkin wrote an essay from Murmansk, on the basis of which he was awarded a prize studentship from the Wellcome Trust in Mathematical Biology to unravel the more complex functions of the peripheral auditory system that have medical application. Mark Maconochie joined from MRC Harwell to study the development of the peripheral auditory system.

Ian Russell and Chris Darwin’s labs have between them fostered the careers of so many hearing scientists that it is impossible to mention them all. Ian Russell, Jonathan Ashmore and Guy Richardson are all now Fellows of the Royal Society. And so was Christopher Longuet-Higgins, and so am I.