Adam Sillito examines Bridget Riley's Rattle at Tate Britain. He wrote about how her art, which has disorienting optical effects, provides a window into how what we "see" can be framed by the brain's expectations. Photo: David Sillitoe/The Guardian
Adam Sillito, emeritus professor of visual sciences at the Institute of Ophthalmology in London, who has died aged 79, described one of his recreations in Who's Who as "dreaming of better things". As a lateral thinker who understood the bigger picture, he conducted research into the mechanisms of visual perception, providing essential knowledge for future treatments. As director of the institute from 1991 to 2006, he transformed it from a depressed area on the brink of closure into a world-class center of excellence, working with Moorfields Eye Hospital and attracting top scientists from around the world.
In the 1970s, Sillito was a lecturer at the University of Birmingham, investigating an aspect of the complex process of visual perception. In order to 'see', neurons must transmit information from the eyes to the visual cortex in the brain, where it is interpreted as images. At the time, researchers were mainly interested in how neurotransmitters have an 'excitatory' effect on neurons, causing them to fire and transmit information to the next cell.
But Sillito was curious if the opposite happens: Do neurotransmitters prevent neurons from firing? In the 1970s he conducted a series of experiments that showed that this is the case: some neurotransmitters do indeed have an inhibitory effect.
It was a fundamental discovery. His colleague Javier Cudeiro said: "Adam showed that the inhibitory component was an important part of vision as we know it. It represented a paradigm shift in the understanding of how the visual system works, which has proven fundamental to the modern understanding of visual neuroscience."
In 1982 Sillito became professor of physiology and head of department at Cardiff University. Both there and later in London, he investigated a key brain area involved in vision, the lateral geniculate nucleus, showing that it played a role in inhibition and is involved in several functions, including helping us sense whether something is the focus of our eyes. is an image or in the background.
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He investigated how vision is influenced by what the brain expects to see. Some vision is done through "bottom-up processing," which means that information comes from the eyes and the brain has no expectations about what it sees. However, "top-down processing" raises expectations about what might happen.
An example of this is approaching passersby with hair or clothing that resembles that of a friend you are waiting for. This type of visual processing involves many parts of the brain, and Sillito's research made important observations that opened up new avenues of research.
In a 2003 Guardian article, Our Lying Eyes, Sillito explained how the art of Bridget Riley - which features disorienting optical effects - provides a window into how visual perception works and how what we "see" can be framed by the expectations of the brain.
In 1987 he was appointed professor of visual sciences at the Institute of Ophthalmology, with the task of trying to turn the tide as it was in danger of closing. The Research Assessment Exercise (now Research Excellence Framework), which rates research in the UK's higher education institutions, had given it the lowest possible score because it had no significant academic output.
A logical, strategic thinker, Sillito knew that if he could recruit good scientists and raise the institute's academic profile, funding would follow, transforming its fortunes. He encouraged researchers to think 'blue skies', relieved them of teaching or management duties and provided attractive conditions, such as good salaries and well-equipped laboratories.
He oversaw the institute's merger with University College London in 1995 and its move to larger premises in Bath Street, adjacent to Moorfields Eye Hospital, with which it had a close working relationship. Funding came from the Wellcome Trust and Sillito convinced the charity Fight for Sight, which had previously supported medical projects, to also support pure research.
It wasn't all smooth sailing: decision makers at the university and Moorfields didn't always agree with him, but Sillito was persistent. The Institute's score on the Research Assessment Exercise rose steadily and in 2008 it was rated "internationally excellent".
Not long before she retired in 2018, his colleague Susan Lightman attended a meeting where institute employees talked about their careers. Like most of her British contemporaries, she said she had spent time in the US because it was at the cutting edge of visual research at the time. The final speaker, however, was a new senior fellow at the institute, who said, "Well, I didn't have to go abroad to graduate." It was a testament to Sillito's work at the institute that young academics could now conduct world-class research in Britain.
Sillito was born in Tamworth, Staffordshire, the son of Adam Sillito, a dairy farmer, and his wife, Jean (née Onion), who was a secretary at the Milk Marketing Board and kept the accounts of the family business. The couple also had two daughters, Margaret and Susan.
From an early age, Adam was interested in cars and all things mechanical, as well as biology, and kept several pets, including a rescued magpie and a jackdaw. At the age of six, he contracted polio and spent two years in the hospital, where he could only see his family from the other side of a glass screen. The disease left its mark on his right arm and prevented him from going to school until the age of eight. A voracious reader, he quickly caught up and passed the 11-plus exam to enter Burton-on-Trent grammar school. He initially studied medicine at the University of Birmingham, but switched to neurophysiology.
After receiving his doctorate, Sillito studied in Baltimore at Johns Hopkins University in 1970-71. He had met physiotherapist Sharon Pascoe in Birmingham when she signed up for a class he was teaching. She came to visit him in the US and they had what she described as a "hippie wedding" in 1971 and went on a road trip to the West Coast and back to celebrate. Returning to Britain, they settled in Birmingham, where Sillito lectured and conducted research at the university.
He retired from UCL in 2014 at the age of 70. Diagnosed with bladder cancer in 2016, he nevertheless continued to enjoy a rich cultural life in London, including poetry, chess, music and visits to Seville and Italy.
He is survived by Sharon, his son Rowland, daughter Francesca and grandchildren Amelia and Laurie, and his sisters.
* Adam Murdin Sillito, visual neuroscientist, born March 31, 1944; died December 17, 2023