NTU's Fully-funded PhD Studentship Scheme 2023
Project ID: S3 7
Much of what we know of sleep across the menstrual cycle is based on contrasts between different phases, sometimes of the same women. Invariably, where sleep has been measured using EEG, this has been done in the unusual circumstances of the sleep laboratory, and consequently under regimens which restrict many aspects of ordinary living (sleeping alone, at prescribed times, under atypical dietary controls, etc.). These studies demonstrate that sleep under such conditions is different before and after ovulation (i.e. follicular and luteal phase), with amount of REM sleep reducing and increased Stage 2 and arousals in the luteal phase (e.g. Baker & Colrain, 2010), perhaps because of a progesterone-driven retention of nightly core body temperature (e.g. Kravitz et al., 2005) or change in circadian pressure across the cycle (e.g. Shechter et al, 2010). Studies of home sleep have not used EEG, the gold standard measures of objectively measuring sleep, but do show what may be a related pattern of results: reported satisfaction with and 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 the methodological compromises necessary because (a) suitable technologies were not available for more naturalistic studies of sleep processes and underpinning physiological change and (b) repeated daily measurement across menstrual cycles was prohibitively challenging, and computationally complex.
The proposed doctoral research will address these issues by conducting a unique combination of methods: EEG sleep studies in women’s own sleep environments, using actigraphy as both a converging method of sleep assessment, but particularly for assessing daily and nocturnal light exposure and activity levels; collecting electronically delivered brief daily diaries, as well as at home continuous measurement of core body temperature in order to track circadian change across the cycle; and hormonal assays to quantify the relationships between changes in levels of sex hormones, activity and sleep. These novel studies will encompass young women whose menstrual cycles are stable and those whose cycles vary in duration, or are otherwise atypical, and later in the PhD extend these analyses beyond the assessment of single cycles to multiple cycles, and will incorporate remote assessment of cognition, affect and wellbeing in order to determine the functional significance of the sleep, circadian and hormonal changes observed.
Dr Fran Pilkington-Cheney (DoS)
Professor John A Groeger
For the eligibility criteria, visit our studentship application page.
How to apply
To make an application, please visit our studentship application page.
Fees and funding
This is part of NTU's 2023 fully-funded PhD Studentship Scheme.
Guidance and support
Application guidance can be found on our studentship application page.