I should like to thank Dr Jake Empson (my MSc Supervisor) of Hull University for providing me with a knowledge of sleep-research technique , and my current Supervisor, Dr Graham Wagstaff, for his valuable comments on my work.

I should especially like to thank the main subject in this study, Alan Worsley of Hull, for his great co-operation over the 3 years of experimentation. Also, all the other subjects who volunteered to spend nights in the sleep-laboratory with no remuneration.

The Department’s workshop staff, under Eric Britton, deserve credit for their friendly efficiency in providing equipment, and I am grateful to Brian Mitchell and Eddy Cookson for designing and constructing the ‘CEMOS’ device to my specifications.