Professor Sir Gabriel Horn, FRS

Doctor of Science

2003

Mr Pro-Vice-Chancellor, Gabriel Horn was Professor of Anatomy at Bristol from 1974 to 1977. He came here from the Department of Anatomy at the University of Cambridge and left to become Head of the Department of Zoology at Cambridge, a post he held until 1995. He was Master of Sidney Sussex College from 1992 to 1999 and Deputy Vice-Chancellor of the University of Cambridge from 1994 to 1997. He was elected a Fellow of the Royal Society in 1986 and was awarded its prestigious Gold Medal in 2001. He obtained an MD in 1965, a DSc in 1975 and an Honorary DSc from the University of Birmingham in 1999. In 2002 he was made a Knight Bachelor for his services to neurobiology and the advancement of scientific research.

I wonder whether Gabriel Horn’s very distinguished academic career was predicted in his report from Handsworth Technical School when he left to become an assistant in the family shop at age 16? Whatever, through day release, he obtained the National Certificate in Mechanical Engineering (with distinctions) and, after a period in the Royal Air Force, went to the University of Birmingham to study medicine. There he excelled, winning, amongst other distinctions, the prize for the highest aggregate marks in Part 1 of the final Examination for the MB ChB degree. In case you think that his background in mechanical engineering predisposed him towards a career in surgery, I must tell you that instead, in 1956, he became a Demonstrator in Anatomy at Cambridge, and this position was followed by his advancement, successively, via a lectureship to a readership, and so to the Chair in Bristol.

Gabriel Horn is widely known as a most gifted teacher, and generations of students have appreciated his lectures. However, Gabriel had, and still has, an overriding passion for research, in particular, a desire to understand the workings of the brain. He was one of the early researchers to have the aim of relating the activity of individual nerve cells to behaviour. Indeed, this theme of understanding how nerve cell activity can explain particular behaviours is common to the many diverse problems that he has tackled in a most varied and wide-ranging research career. The diversity and range of this research is shown in his publications that record important advances in knowledge and understanding in the fields of perception – particularly mechanisms underlying how we see – attention and consciousness – notably how we select what we want to attend to – and memory.

One of the attributes of a great scientist, and Gabriel Horn is a great scientist, is to have ideas and publish papers years ahead of the field. As scientists know, it is unhappily true that this means that the original work has often been forgotten when the field eventually catches up. Another essential attribute of a great scientist is to get things right but, as scientists also know, this is less common in science than media-led public opinion might lead one to suppose. I could give you a list of examples from Gabriel’s work of his getting things right well in advance of the field, but here is one from when I first got to know Gabriel while I was his research student in Cambridge before he came to Bristol. Gabriel was exploring interactions between sensory systems, in particular, how tilting the head, which generates signals from the balance organs in the ear, affects the way that the visual system processes its information – if you like, seeking why we should continue to see the world as the same way up when we tilt our head to one side. The findings that so called visual areas of the brain could have their activity altered by inputs from the balance organs attacked the prevailing orthodoxy and consequently sparked much controversy when first published, but years later these findings have found their confirmation in the work of others, and such sensory interactions have become topics of widespread scientific interest.

Amongst his broad range of different contributions to the understanding of brain mechanisms, Gabriel’s major focus has been his interest in how the brain lays down memories. He published an article containing a theory of memory even before he began his formal research career in Cambridge, and he is still continuing to research into and publish papers on memory mechanisms, although more than ten years ago he reached an age at which normal individuals might be expected to retire. Memory in all its various forms is critically important to our everyday life and to each of us in our understanding of ourselves as individuals with our own unique life times of past experiences. Accordingly, understanding the basis of memory within the brain is widely considered to be one of the key scientific challenges of our time. Gabriel Horn has been an internationally recognised leader in this field of brain research for some forty years. During this time, through meticulous and imaginative research, Gabriel with his colleagues managed first to uncover changes in the biochemistry of the brain that could be unequivocally related to learning. He was then the first to identify an anatomical region of the brain that was unambiguously a site of long-term information storage, a place where memories are formed and held. This work involved a synthesis of the results of anatomical, biochemical, physiological, pharmacological and psychological experiments. In turn, the findings led to further discoveries of particular biochemical and anatomical changes related to how learning changes the way nerve cells connect to each other, and descriptions of how the activity of nerve cells at the storage site changes during learning. Indeed, Gabriel is currently still very actively pursuing these researches and again, the new findings of this research are challenging current orthodoxies.

Gabriel Horn has also contributed to science in numerous other important ways, for example by being a member of and chairing Scientific Research Council Committees, notably for the Biotechnology and Biological Sciences Research Council (formerly the Agricultural and Food Research Council). Here his expertise led to him chairing a Working Group on the Biology of the Spongiform Encephalopathies that was set up to see to the funding of research into BSE. It was this background that further led to the Government asking Gabriel to become Chair of the Committee to Review the Origin of BSE, which presented its report to Secretaries of State for the Environment and for Health in 2001. In 1998 he initiated and became Committee Chair of the Cambridge University Government Policy Programme. The purpose of this Programme is to provide scientific policy advice to the Government. One specific current spin-out from this work is the Government’s Foresight Programme into Cognitive Systems. This Programme has the aim of bringing together biological, physical and computer scientists to identify key problems whose solution could have a major impact upon society. It is appropriate that two areas identified as being of particular importance within this Programme are interactions between sensory systems and how the brain stores memories. As so many times before, it turns out that Gabriel is not only currently a leader but that he also has been there before, well ahead of the field.

Mr Pro-Vice-Chancellor, for his outstanding contributions to science, I am delighted to present to you Professor Sir Gabriel Horn as eminently worthy of the degree of Doctor of Science honoris causa.