Nottingham Trent University Open PhD Positions

Most sleep research has been conducted on males and, historically, research focusing on women’s health has been neglected. Much of what we do know of sleep across the menstrual cycle is based on contrasts between different ‘phases’ (times of the month). Where sleep has been measured using brain activity (Electroencephalography, EEG – the gold standard measure of objectively measuring neural activity during sleep), this has been done in the sleep laboratory and under conditions which restrict many aspects of ordinary living. These studies demonstrate that sleep under such controlled conditions is different before and after ovulation, with amount of REM sleep, duration of Stage 2 and arousals in the luteal phase reducing (e.g., Baker & Colrain, 2010). This might be because of a progesterone-driven retention of nightly core body temperature (e.g., Kravitz et al., 2005) or changes in circadian pressure across the cycle (e.g., Shechter et al, 2010). Additionally, studies of home sleep have not used EEG but do show a possible related pattern of results: reported satisfaction with quality of sleep also appears to decrease after ovulation (Baker & Driver, 2004; Groeger et al., in prep.). These findings are important, but they are limited by necessary methodological compromises: either suitable technologies were not available (which would allow for more naturalistic studies of sleep processes and underpinning physiological change) or repeated daily measurement across menstrual cycles was prohibitively challenging, and computationally complex.

The proposed doctoral research will address these issues by conducting EEG sleep studies in women’s own sleep environments. Actigraphy will be used as a converging method of sleep assessment, and for assessing daily and nocturnal light exposure and activity levels. The research will also involve collecting online daily diaries, at home continuous measurement of core body temperature to track circadian change across the cycle, and importantly collecting hormonal assays which will quantify the relationships between changes in levels of sex hormones, activity and sleep. These studies will encompass young women whose menstrual cycles are stable and those whose cycles vary in duration or are otherwise atypical. Later in the PhD, these analyses will be extended beyond the assessment of single cycles, and will incorporate remote assessment of cognition, affect and wellbeing to determine the functional significance of the sleep, circadian and hormonal changes observed.

Supervisory Team:

Director of Studies: Angharad Williams 

NTU co-supervisors: Fran Pilkington-Cheney, John Groeger