Professor Ian Oswald - Telegraph He won a scholarship to read Medicine at Gonville and Caius College, Cambridge, gaining a First in Psychology before moving to Bristol to complete his clinical training. After two years National Service in the RAF, where he recorded the electrical activity in airmen's brains to test for a propensity to conditions such as epilepsy, he spent a further two years as a research fellow at Oxford, returning to Cambridge for his MD in 1959. The same year he became a lecturer in the Department of Psychological Medicine of Edinburgh University, where he would remain for the rest of his career. He was probably best known in academic circles for proposing what is known as the "systematic restoration" theory of sleep. He observed that people who had suffered damage to the brain - for example through drug or alcohol abuse - spend more time than normal in what is known as the rapid eye movement (REM) or dreaming stage of sleep, as they recovered. He also noted that during "orthodox, non-dreaming (NREM) sleep," there was a substantial increase in the release of the growth hormone from the pituitary gland. From these and other observations he concluded that NREM sleep aids the growth and renewal of general body tissues, while REM sleep serves the same purpose for brain tissues. To prove the case, Oswald and a colleague injected themselves for a week with small doses of heroin, which causes slight brain damage. After stopping the drug, there was a sudden increase in their REM sleep. Meanwhile, in experiments carried out on people with an excess of thyroid hormone, a substance that "burns up" the body, he noted that subjects with overactive thyroids tend to have a greater degree of deep NREM sleep. One of Oswald's early experiments, published in the British Medical Journal in 1960, reached a wider audience when it featured in a book entitled Elephants on LSD: the Ten Silliest Experiments of All Time by Alex Boese. The book recorded how Oswald recruited three volunteers to test how much stimulus someone could be exposed to while awake and still drop off. After prising their eyes open with tape, he placed a bank of flashing lights in front of them about 50 centimetres away. Electrodes attached to their legs delivered a series of painful shocks. As a finishing touch, he blasted "very loud" blues music into their ears. Of the three young guinea pigs, one was severely sleep-deprived but the other two were fully rested. Yet, remarkably, despite the shocks, lights, music and open eyes, all three men dozed off within 12 minutes. Oswald speculated that the key to this unexpected result lay in the monotonous nature of the stimuli. Faced with such monotony, he suggested, the brain goes into a kind of trance. Instead of becoming aroused by the stimulation, the brain becomes habituated to it and shuts down. This, he suggested, may explain why it is easy to doze off while driving along an empty road. He was appointed to a personal chair in Psychiatry in 1977. From 1965 to 1967, on leave from Edinburgh, he established a Department of Psychiatry in the University of Western Australia. His 1966 book, Sleep, became a bible among sleep researchers, while How to Get a Better Night's Sleep (1983), written with Kirstine Adam, became the insomniac's bible. During his time at Edinburgh, Oswald, a keen horticulturalist and wine connoisseur, was awarded the Royal Medico-Psychological Association's Gaskell Medal and Prize, and became a Foundation Fellow of the Royal College of Psychiatrists. His first wife Joan (née Thomsett) predeceased him. He is survived by his second wife and by four children of his first marriage. Professor Ian Oswald, born August 4 1929, died April 25 2012