Ray Guillery performed important studies of the brain, especially the hypothalamus, the visual system and the thalamus. In his early research, Ray used axonal degeneration techniques to study the hypothalamus; he also pioneered electron microscopy of the central nervous system, and with S. Murray Sherman helped define the criteria for distinguishing inputs to the thalamus for relay to cortex (drivers) from modulators, which are not relayed to cortex.
They also showed that a major driver input to the thalamus comes from the cerebral cortex, establishing a hierarchy of transthalamic corticocortical connections, distinct from better studied direct corticocortical connections. He described pathway abnormalities in squinting Siamese cats and other albino mammals. He showed that unilateral lid closure produces more severe effects through binocular competition than it does through visual deprivation.
In the considerable recent advances of knowledge of the thalamus, he and Murray made important contributions, in particular showing that most driver inputs to the thalamus provide cortex with information about upcoming movements, providing a distinction between self-generated acts and acts produced by others.
Professor Ray Guillery FRS died on 7 April 2017.