Adam Sillito, emeritus professor of visual science 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”. A lateral thinker who grasped the bigger picture, he conducted research into the mechanics of visual perception that yielded essential knowledge for future treatments. As director of the institute from 1991 to 2006, he transformed it from a backwater on the brink of closure to a world-class center of excellence, along with Moorfields Eye Hospital and attracting top scientists from around the world.
In the 1970s, Sillito was a lecturer at the University of Birmingham and exploring 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 mostly 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 to know if the opposite happens: Do neurotransmitters inhibit neurons from firing? He undertook a series of experiments in the 70s that proved this to be the case: some neurotransmitters do have an inhibitory effect.
This was a fundamental discovery. His colleague Javier Cudeiro said: “Adam demonstrated that the inhibitory component was an important part of vision as we know it. This represents a paradigm shift in the conception of how the visual system works, which has proven to be 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 explored a key brain area involved in vision, the lateral geniculate nucleus, and showed that it has a role in inhibition and is involved in various functions, including helping us see whether something that is the focus of an image or is in the background.
He researched how vision is affected by what the brain expects to see. Some vision occurs through “bottom-up processing”, meaning that information comes in from the eyes and the brain has no expectations about what it sees. However, in “top-down processing” expectations are set for what it can see.
An example of this is going up to passers-by with hair or clothing similar to that of a friend you are waiting for to arrive. This type of visual processing involves many parts of the brain and Sillito’s research contributed important observations that opened up new avenues of research.
In a Guardian article in 2003, Our lying eyes Sillito explained how Bridget Riley’s art – which has disorienting optical effects – provides a window into how visual perception works and how what we “see” can be framed by the brain’s expectations.
In 1987 he was appointed professor of visual science at the Institute of Ophthalmology, tasked with trying to turn it around as it was likely to close. The Research Assessment Exercise (now Research Excellence Framework), which assesses research in the UK’s higher education institutions, gave it the lowest possible score because it had no significant academic output.
Sillito, a logical, strategic thinker, knew that if he could recruit good scientists and raise the academic profile of the institute, funding would follow that changed his fortunes. He encouraged researchers to do “blue skies” thinking, exempting them from teaching or management duties and providing attractive conditions, such as good salaries and well-resourced laboratories.
He oversaw the institute’s merger with University College London in 1995 and its move to larger premises on Bath Street, adjacent to Moorfields Eye Hospital, with which it had a close partnership. Funding poured in from the Wellcome Trust and Sillito persuaded the charity Fight for sightwhich has so far supported medical projects, to also support pure research.
It wasn’t obvious: 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 by 2008 it was rated “internationally excellent”.
Not long before she retired in 2018, his colleague Susan Lightman attended a meeting where staff at the institute talked about their careers. Like most of her British contemporaries, she said that she spent time in the US because it led the way in visual research at the time. However, the last speaker was a new senior fellow at the institute, who said, “Well, I don’t need to go abroad to succeed.” It was a testament to Sillito’s work at the institute that young academics could now conduct world-class research in the UK.
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 family farm accounts. The couple also had two daughters, Margaret and Susan.
From an early age, Adam was interested in cars and anything mechanical, as well as in biology, and kept several pets, including a rescued magpie and cheetah. At the age of six, he contracted polio and had to spend two years in hospital, seeing his family only from the other side of a glass screen. The disease left its mark on his right arm and meant that he only started school at the age of eight. A voracious reader, he quickly passed the 11-plus exam to attend Burton-on-Trent Grammar School. He initially studied medicine at the University of Birmingham, but switched to neurophysiology.
After his PhD, Sillito in Baltimore at Johns Hopkins University in 1970-71. He met physiotherapist Sharon Pascoe in Birmingham when she signed up for a class he taught. She came out to be with 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 the UK, they made their home in Birmingham, where Sillito lectured and conducted research at the university.
In 2014 he retired from UCL, aged 70. He was diagnosed with bladder cancer in 2016, but nevertheless continued to enjoy a rich cultural life in London, which included poetry, chess, music and visits to Seville and Italy has.
He is survived by Sharon, his son, Rowland, daughter, Francesca, and grandchildren, Amelia and Laurie, and by his sisters.
