The newly constructed Sleep Research Laboratory consists of four environmentally controlled bedrooms, experimenter/equipment room, kitchen/lounge area, toilets and shower. The bedrooms are equipped to record EEG, EMG, EOG, movement, breathing, and body temperature and transmit this data to computers. Available for field use are three digital sleep monitors, 30 wrist activity monitors used to measure sleep non-invasively, and 10 experimental light "glasses" used for light therapy. The facilities allow basic research into sleep and circadian rhythms as well as applied research into insomnia treatments.
Contact: Professor Leon Lack
Present insomnia treatment project
Information about the new sleep research undertaken by the School of Psychology on Youtube.
Cognitive/behaviour therapy (CBTi) and CBTi in combination with evening bright light therapy for the treatment of Sleep Maintenance Insomnia
Difficulty in maintaining sleep and/or waking too early and not being able to return to sleep is a common type of chronic insomnia. It has been associated with circadian rhythms (body clock) timed earlier than normal. It should be possible to normalize the rhythms of these insomnia sufferers with the use of evening bright light therapy. This project used the more traditional cognitive/behaviour therapy(CBTi) and compared it with the combination of CBTi and evening bright light therapy. CBTi was as effective as the two in combination. The next study will evaluate whether evening bright light alone is also an effective treatment for this type of insomnia.
National Health and Medical Research Council, 2008-2011.
Lack, L. (2011). Broken sleep? It’s a roller coaster ride. The Conversation: Hot Topics, August 10, 2011. http://theconversation.edu.au/broken-sleep-its-a-rollercoaster-ride-1792
Lovato, N., Lack, L., Wright, H., Cant, M., & Humphries J. (2011). Do older adults with insomnia have impaired working memory performance? Sleep, 34, A170. (25th Annual Meeting of the Associated Professional Sleep Societies, Minneapolis, Minn. USA, June, 2011).
Wright, H., & Lack, L. (2010). Sleep well, live better: 3 steps to good sleep. Sydney, Media 21 Publishing Pty. Ltd.
Lovato, N., Lack, L., Wright H. (2011). A randomized controlled trial of a combined treatment of cognitive behaviour therapy and evening bright light therapy for insomnia in older adults. Sleep, 34, A173-4. (25th Annual Meeting of the Associated Professional Sleep Societies, Minneapolis, Minn. USA, June, 2011).
The benefits of brief naps
We have now compared the relative benefits on alertness and performance following afternoon naps of varying lengths (0.5 minutes, 1.5 min, 5 min, 10 min, 20 min, and 30 min). The ultra brief sleeps up to 5 minutes produced very little improvements. However, 10 minutes of sleep was followed by improvements in all alertness and performance measures soon after the nap that lasted for up to 2-3 hours. Following the longer sleeps of 20 and 30 minutes there was some impairment of alertness immediately after the naps, known as sleep inertia, with some improvement emerging an hour after the longer naps, but not better than the 10 minute nap. It appears that the “power nap” now has scientific support. At present we are investigating whether regular nappers benefit from a nap more than those who rarely nap.
Flinders University 2002-2004
Austalian Research Council 2005-2008
Professor Leon Lack
Dr Sally Ferguson, The University of South Australia
Tietzel, A., & Lack, L. C. (2002). The recuperative value of brief and ultra-brief naps on alertness and cognitive performance. Journal of Sleep Research, 11, 213-218.
Brooks, A. J., & Lack, L. C. (2006). A brief afternoon nap following nocturnal sleep restriction: Which nap duration is more recuperative? Sleep, 29, 831-840.
Lovato, N., Lack, L. C., Ferguson, S., & Tremaine, R. (2009). The effects of a 30-min nap during night shift following a prophylactic sleep in the afternoon. Sleep and Biological Rhythms, 7, 34-42.
Lovato, N., & Lack, L. C. (2010). The effects of napping on cognitive functioning. In G.A. Kerkhof and H.P.A. van Dongen (Eds.) Human Sleep and Cognition. Vol. 185, Oxford: Elsevier Science, 155-166.
Circadian rhythm phase shifting with the use of small light sources
Bright light stimulation has the capacity to shift the timing of circadian (24-hour) rhythms of humans (the body clock). Sunlight or specially constructed bright light boxes generating up to 3,000 lux of light at the eyes can shift the timing of circadian rhythms to a later or earlier time dependent on the timing of the light exposure. This phenomenon can be used therapeutically to treat certain types of insomnia, jet lag, shift work fatigue, and winter depression. However, these light sources are often not available and have disadvantages of non portability and inconvenience which reduce patient compliance and therapeutic effect. To overcome these disadvantages we have developed small light emitting diodes (EDs) as an effective light source. Although their total light output is minuscule compared to the sun or light boxes, placed close to the eyes they can provide up to 2,000 lux of light intensity. The first studies have found significant melatonin suppression and phase delay during and following LED light stimulation but only with certain LED colours. The studies have found the most effective LED colours to use for circadian rhythm re-timing are in the blue and blue/green end of the colour spectrum. This research has led to the commercial development of blue LED glasses for the application of bright light therapy such as, for sleep difficulties caused by these body clock disorders.
Flinders Technologies, 1999-2000.
Lack, L. C., Wright, H., Gibbon, S., & Kemp, K. (2005). The treatment of early-morning awakening insomnia with two evenings of bright light. Sleep, 28, 616-623.
Wright, H. R., Lack, L. C., & Kennaway, D. F. (2004). Differential effects of light wavelength in phase advancing the melatonin rhythm. J Pineal Res, 36, 140-144.
Wright, H. R., Lack, L. C., & Partridge, K. J. (2001). Light emitting diodes can be used to phase delay the melatonin rhythm. Journal of Pineal Research, 31(4): 350-355.
Wright, H. R., & Lack, L. C. (2001). Effect of light wavelength on suppression and phase delay of the melatonin rhythm. Chronobiology International, 18(5): 801-808.
The Circadian (24-hour) Rhythms of Delayed Sleep Phase Disorder (DSPD)
Night “owls” (evening types) stay up later at night and sleep in late in the morning when they have the opportunity to do so. This late sleep pattern is associated with a circadian rhythms timed later than normal making it difficult to get to sleep and wake up at normal times. During a normal work week they have difficulty getting to sleep early enough to get sufficient sleep by the time they have to awaken in the morning to get to work, school, or other commitments. They have difficulty arising at these early times and do not feel proficient or sociable until much later in the day. When given the opportunity to catch up on this lost sleep (weekends or holidays) they easily sleep-in very late. However, this exacerbates their difficulty when returning to their normal schedule because it further delays their circadian rhythms. http://theconversation.edu.au/forget-bob-geldof-this-is-why-you-dont-like-mondays-828
This pattern is common in adolescents and young adults and significantly interferes with their daytime alertness, mood, and productivity. Delayed Sleep Phase Disorder is a more extreme degree of evening type symptoms. DSPD sufferers have a sleep period 3-6 hours later than normal and find it almost impossible to shift their sleep/wake pattern earlier to a more normal time. We are presently investigating the basic chronobiology and sleepiness rhythms of DSPD sufferers in the Sleep Laboratory using a novel methodology. It consists of an 80 hour (long weekend) bed-rest routine free of time cues in which sleep/wake alternates in 20/40 minute periods respectively throughout this period. In this way we will measure the endogenous circadian rhythms of core body temperature, melatonin, cortisol, hunger drive, objective and subjective sleepiness, and cognitive performance capacity. The main aim will be to evaluate how quickly the rhythms delay in DSPD participants compared to normal and thus determine the endogenous period lengths of these rhythms. If, as we hypothesize, the period lengths are very much longer in DSPD, more effective therapies than those presently used can be designed and tested.
Flinders University, 2011.
Lack, L. C. & Wright, H .R.(in press). Circadian rhythm disorders 1: Phase-advanced & phase-delayed disorders. In C. Espie & C. Morin (Eds.). Oxford Handbook on Sleep and Sleep Disorders. Oxford University Press.
Lack, L. C., Wright, H. R., & Bootzin, R. R. (2009). Delayed sleep-phase disorder. Sleep Medicine Clinics 4: 229-239. – Topic Issue, Circadian Rhythms and Sleep.
Lack, L., Bailey, M., Lovato, N., Wright, H. (2009). Chronotype differences in circadian rhythms of temperature, melatonin, and sleepiness as measured in a modified constant routine protocol. Nature and Science of Sleep 1:1-8.
Lack, L. C., Gradisar, M., Van Someren, E. J. W., Wright, H. R., & Lushington, K., (2008), The relationship between insomnia and body temperatures. Sleep Medicine Reviews 12(4): 307–317.
Lack, L., Bramwell, T., Wright, H., & Kemp, K. (2007). Morning blue light can advance the melatonin rhythm in mild delayed sleep phase syndrome. Sleep and Biological Rhythms 5:78-80.
The effects of pre-sleep technology use on adolescents’ sleep
Technology use in the hour prior to bedtime is prevalent, especially for teenagers. Many surveys of teenagers show that technology use prior to bed is associated with later bedtimes, less sleep, and greater daytime tiredness. However, controlled experimental studies are needed to be confident about how technology use affects sleep and how much can be safely used before bedtime. Our research to date has shown (1) playing a violent videogame for 1 hour before bedtime resulted in a mild effect on falling asleep, (2) playing a violent videogame for 150 min before bed results in a long time to fall asleep, less sleep, and more poor sleep quality, and (3) 1 hr of bright screen light from iPads do not affect sleep. Our future research projects will investigate other factors suspected to explain the relationship between technology and sleep, including, arousal, competition, and socialisation and morality.
Dr Michael Gradisar
Dr Daniel King
Dr Aaron Drummond
Ms Cate Warland
Cain, N., & Gradisar, M. (2010). Electronic media use and sleep in school-aged children and adolescents: A review. Sleep Medicine, 11, 735-742.
Gradisar, M., & Short, M. (in press, accepted 15.1.12). Sleep hygiene and environment: Role of technology. In A. R. Wolfson and H. Montgomery-Downs (Eds.), Oxford handbook of infant, child, and adolescent sleep: Development and problems. Oxford, UK: Oxford University Press.
King, D., Gradisar, M., Drummond, A., Lovato, N., Wessel, J., Micic, G., Douglas, P., & Defabbro, P. (in press, accepted 13.9.12). The impact of violent videogaming on adolescent sleep-wake activity. Journal of Sleep Research.
National Sleep Foundation. (2011). 2011 Sleep in America Poll: Communications technology in the bedroom. Washington, DC: (see http://www.sleepfoundation.org/article/sleep-america-polls/2011-communications-technology-use-and-sleep)
Weaver, E., Gradisar, M., Dohnt, H., Lovato, N., & Douglas, P. (2010). The effect of pre-sleep video game playing on adolescent sleep. Journal of Clinical Sleep Medicine, 6, 184-189.
Dr Helen Wright, Flinders University
Dr Michael Gradisar, Flinders University
Prof Richard Bootzin, U. Arizona, USA
Prof Mary Carskadon, Brown University, USA
Dr Sally Ferguson, University of South Australia
Dr David Kennaway, University of Adelaide
Associate Prof Helen Burgess, Rush University Medical Centre, Chigago, USA
AlumniProfessor Drew Dawson, University of SA
Associate Professor Kurt Lushington, University of SA
Dr Crisetta MacLeod-Morgan
Dr Helen Wright, Flinders University
Dr Michael Gradisar, Flinders University
Dr Jeremy Mercer, Adelaide Institute of Sleep Health
Dr Amber Brooks, Lion-Nathan Pty Ltd.
Dr Jodie Harris, Adelaide Institute for Sleep Health