Obituary - Martin Halliday

10 June 2008

BCS Life fellow Martin Halliday FBCS CITP has died aged 81. Martin was a consultant neurologist and neurophysiologist and some of his earliest work was on a way to detect the effects of sleep deprivation in pilots flying as part of the 1948 Berlin airlift.

He devised a simple examination to reveal a type of tremor seen in certain hand muscles after a lengthy period of sleep deprivation. The test correlated well with the risk of suddenly falling asleep, and could be used to good effect to withdraw pilots from duty before they became a danger to themselves and others.

This work led to him working in the Neurological Research Unit at the National Hospital for Nervous Diseases in London where he began studying the neural mechanisms underlying various types of tremor in hospital patients. Before long, however, his interest crystallised in the investigation of changes in brainwave patterns after stimulation of one or other of the five senses.

These tiny potentials were notoriously difficult to single out from the profusion of voltage spikes characterising the recording of brainwave activity (electroencephalography or EEG) in the 1950s.

It was at this time that Dr G.D.Dawson described a technique of averaging that could be used to extract EPs from the background EEG. His first averager was a crude - by today's standards - electromechanical analog computer. By 1960, however, the potential of digital computing was dawning, and Halliday demonstrated a small digital averager he had made to the Physiological Society in 1961. He was convinced that Dawson's work could be carried forwards by constructing a larger system and writing the programme to run it.

Halliday was joined by Dawson's technician, Jack Pitman, and by 1965 they had built a system capable of producing clear tracings of EPs resulting from various peripheral stimuli.