Sleep

Sleep research at NTU builds upon John Groeger’s collaborations at Surrey’s Sleep Research Laboratory (University of Surrey) and School of Applied Psychology (University College Cork). Commitment to exploring the functional significance of different aspects of sleep, and individual differences in vulnerability to the effects of sleep loss continues, but collaborations with new colleagues has enabled us to build programmes which address sleep’s importance to health and wellbeing, its social context, and implications for everyday cognition.

Thus far, a dozen or more academic staff have become engaged in specific projects, all with clear outputs planned for this/early next academic year). These are: Couples’ sleep (Dr. Lydia Harkin); Sleep in prisons (Dr. Karen Slade); Campus wide Sleep Service scoping study (Dr. Maria Karanika-Murray, Dr. Mike Marriott and Dr. Eva Sundin); Sleep and group identification (Dr. Blerina Kellezi and Dr. Juliet Wakefield); Sleep in families with disability (Dr Rebecca Stack); Sleep and autobiographical memory (Dr Lucy Justice); Sleep and homelessness (Rachel Harding, thought-piece commissioned by The Conversation).

The sleep group has two current PhD students, one investigating the effects of portable device use and emitted light on adolescents’ sleep (Holden, supervisors Professor John Groeger, Dr. Nadja Heim, Dr. Rebecca Stack), and the effects of sleep loss on inflammation (Heasman, supervisors Professor John Groeger, Dr. Suvo Mitra).

Major objectives for 2018-19 is the establishment of a fully functional sleep laboratory, appointment of staff with sleep expertise, seeking external funding for research collaborations and additional doctoral students, and perhaps the development of a campus-wide sleep service for staff and students.

Ongoing areas of investigation include:

• Specific functions of sleep structure
• Cognitive consequences of sleep and sleep loss
• Individual differences in sleep and sleep loss vulnerability
• Sleep, health and environment
• Sleep, caring and development

You can contact the group at sleep@ntu.ac.uk.

• Children’s Sleep Charity
• Family Fund
• University College Cork
• University of Surrey
• National University of Singapore

Specific functions of sleep structure

• Groeger, J.A., Stanley, N., Deacon, S., Dijk, D.J. (2014). Dissociating Effects of Global SWS Disruption and Healthy Aging on Waking Performance and Daytime Sleepiness. Sleep, 37(6):1127-42.
• della Monica, C., Atzori, G., Johnsen, S., Groeger, J.A., Dijk, D.J. (in press). Rapid-Eye-Movement Sleep, Sleep Continuity and Slow Wave Sleep as Predictors of Cognition, Mood and Subjective Sleep Quality in Healthy Men and Women, Aged 20-84 Years. Frontiers in Psychiatry.
• Dijk, D.J., Stanley, N., Groeger, J.A., & Deacon, S. (2012). Enhanced SWS and Improved Sleep Maintenance after Gaboxadol Administration in a Traffic Noise Model of Transient Insomnia. Journal of Psychopharmacology, 6(8):1096-107.

Cognitive consequences of sleep and sleep loss

• Lo, C.Y., Groeger, J.A., Santhi, N., Arbon, E.L., Lazar, A.S., Hasan, S., von Schantz, M, Archer, S.N, Dijk, D-J., (2012.). Effects of partial and acute total sleep deprivation on performance across cognitive domains, individuals and circadian phase. PLoS ONE, 7(9). e45987.
• Lo, C.Y., Dijk, D-J.,Groeger, J.A. (2014). Comparing the effects of nocturnal sleep and daytime napping on declarative memory consolidation.  PLoS ONE. 9(9): e108100. doi: 10.1371/ journal.pone.0108100.
• Groeger, J.A., Lo, J.C.Y., Burns, C.B., Dijk, D.J. (2011). Effects of sleep inertia following daytime naps increase with executive load and vary with time of day. Behavioral Neuroscience, 125(2):252-60.

Individual differences in sleep and sleep loss vulnerability

• Lázár, A., Slak, A, Lo, J.C.Y., Santhi, N. von-Schantz, M., Archer, S.N., Groeger, J.A., & Dijk, D.J. (2012). Phenotypic variations in sleep timing, psychological and health measures in the PER3 VNTR. Chronobiology International, 29, 2, 131-146.
• Santhi, N., Lazar, A.S., McCabe, P.J., Lo, J.C., Groeger, J.A., Dijk, D.J. (2016) Sex differences in the circadian regulation of sleep and waking cognition in humans. Proceedings of National Academy of Sciences, 113, 19, E2730-E2739.

Sleep, health and environment

• Santhi, N., Groeger, J.A., Archer, S.N., Gimenez, M., Schlangen, L.C.M., & Dijk, D.J. (2013). Morning Sleep inertia in Alertness and Performance: Effect of CognitiveDomain and White Light Conditions, PLoS ONE, 8(11):e79688.
• Groeger, J.A. and  Harding, R. Sleep and homelessness. The Conversation.

Sleep, caring and development

• Lo, C.Y., Groeger, J.A., Cheng, G.H., Dijk, D-J., Chee, M.W.L. (2016). Self-Reported Sleep Duration and Cognitive Performance in Older Adults: A Systematic Review and Meta-Analysis. Sleep Medicine. 17, 87–98.
• Groeger, J.A. and Stack, R. (submitted). Sleep in families managing disability: the impact of multiple disabilities on child and carer sleep onset, duration and quality.
• Groeger, J.A. and Stack, R. (submitted). Carer-reported sleep, health and well-being in disabled children and their carers: The wear and tear of care.

The group has access to:

• Act-Trust actigraphy
• Somnia portable PSG
• Dedicated sleep laboratory
• Hormonal and cytokine assays
• Cognitive Performance Test Battery
• Online surveys and Ecological Momentary Analysis