We do not understand why humans need to sleep, however, it is emerging that sleep is related to cognition and neurodegenerative disease, including Alzheimer's disease; the most common cause of dementia worldwide and a leading cause of death. Understanding the relationship between sleep and neurodegeneration is essential to develop treatments for these devastating diseases.

Actigraphy enables us to analyse sleep over prolonged periods using a worn device. The MRC National Survey for Health and Development 1946 (NSHD) is the longest continuously running birth cohort in the world. Initially comprising 5362 subjects born in Britain in the same week in 1946. Study members have been prospectively assessed from birth to the present, over 24 waves of collection, including sleep data. Insight 46, a sub-study of NSHD, has recruited 502 subjects for serial multimodal PET and MRI imaging, cognitive assessment, actigraphy, genetics, and an array of CSF and plasma biomarkers. ~20% have evidence of preclinical Alzheimer’s disease.

Despite the growing evidence for the role of sleep in the cognition of healthy subjects, and in neurodegenerative disease, there is a paucity of long-term data on the effects of sleep over the human lifetime, and in the prodromal phases of neurodegeneration.

Combining unparalleled life-long epidemiological and sleep questionnaire data with high quality multimodal neuroimaging, detailed cognitive assessment, sleep questionnaires, wrist actigraphy, and an array of biomarkers I will undertake a comprehensive examination of the relationships between sleep, cognition and biomarkers; in both aging and neurodegeneration in Insight 46, a subset of the British 1946 birth cohort. I hope to answer key questions, including how sleep changes over a human lifetime, and how sleep throughout life is related to cognition and neurodegenerative disease.

Following the fellowship from Brain, Joshua has also been award the MRC Clinical Research Training Fellowship.