Professor Steven Lockley

Professor Steven W Lockley

Professor, Vice-Chancellor Fellow
BSc (Hons), PhD

Academic and research departments

Surrey Sleep Research Centre, School of Biosciences.


Research projects


Postgraduate research supervision




Original reports (2017-date)

76. Bullock B, Murray G, Anderson JL, Cooper-O’Neil T, Gooley JJ, Cain SW, Lockley SW. Constraint is associated with earlier circadian phase and morningness: Confirmation of relationships between personality and circadian phase using a constant routine protocol. Personality and Individual Differences 2017; 104:69–74. PMID: 28216802

77. Sullivan JP, O’Brien CS, Barger LK, Rajaratnam SMW, Czeisler CA, Lockley SW; The Harvard Work Hours, Health and Safety Group. Randomized, prospective study of the impact of a workplace-based sleep health program on firefighter injury and disability. Sleep 2017; 40(1). doi: 10.1093/sleep/zsw001. PMID: 28364446

78. Murray JM, Sletten TL, Magee M, Gordon C, Lovato N, Bartlett DJ, Kennaway DJ, Lack LC, Grunstein RR, Lockley SW, Rajaratnam SMW. Delayed Sleep on Melatonin (DelSoM) Study Group. Prevalence of circadian misalignment and its association with depressive symptoms in delayed sleep phase disorder. Sleep 2017; 40(1). doi: 10.1093/sleep/zsw002. PMID: 28364473

79. St. Hilaire MA*, Rüger M*, Fratelli F, Hull JT, Phillips AJK, Lockley SW. Modeling neurocognitive decline and recovery during repeated cycles of extended sleep and chronic sleep deficiency. Sleep 2017; 40(1). doi: 10.1093/sleep/zsw009. PMID: 28364449

80. Rahman SA, St. Hilaire MA, Chang AM, Santhi N, Duffy JF, Kronaeur RE, Czeisler CA, Lockley SW, Klerman EB. Circadian phase resetting by a single short-duration light exposure. JCI Insight 2017; 2(7):e89494. PMID: 28405608 PMCID: PMC5374060

81. Rahman SA, St. Hilaire MA, Lockley SW. The effects of spectral tuning of evening ambient light on melatonin suppression, alertness and sleep. Physiology and Behavior 2017; 177: 221-229. PMID: 28472667

82. Phillips AJK*, Clerx WM*, O’Brien CS, Sano A, Barger LK, Picard RW, Lockley SW, Klerman EB, Czeisler CA. Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timing. Scientific Reports 2017; 7(1):3216. PMID: 28607474 PMCID: PMC5468315

83. Sletten TL, Ftouni S, Nicholas CL, Magee M, Grunstein RR, Ferguson S, Kennaway DJ, O’Brien D, Lockley SW, Rajaratnam SMW. Randomised controlled trial of the efficacy of a blue-enriched light intervention to improve alertness and performance in night shift workers. Occupational and Environmental Medicine. 2017; 74(11):792-801. PMID: 28630378

84. Flynn-Evans EE, Shekleton JA, Miller B, Epstein LJ, Kirsch D, Brogna LA, Burke LM, Bremer E, Murray JM, Gehrman P, Rajaratnam SMW, Lockley SW. Circadian phase and phase angle disorders in primary insomnia. Sleep 2017; 40(12). PMID: 29029340

85. Cohen S, Fulcher BD, Rajaratnam SMW, Conduit R, Sullivan JP, St Hilaire MA, Phillips AJ, Loddenkemper T, Kothare SV, McConnell K, Ahearn W, Braga-Kenyon P, Schlesinger A, Potter J, Bird F, Cornish KM, Lockley SW. Behaviorally-determined sleep phenotypes are robustly associated with adaptive functioning in individuals with low-functioning autism. Scientific Reports 2017; 7(1):142287. PMID: 29079761 PMCID: PMC5660229

86. Kelley P, Lockley SW, Kelley J, Evans MDR. Is 8:30 a.m. still too early to start school? A 10:00 a.m. school start time improves health and performance of students aged 13-16. Frontiers in Human Neuroscience 2017; 11:588. PMID: 29276481 PMCID: PMC5727052

87. Cohen S*, Fulcher BD*, Rajaratnam SMW, Conduit R, Sullivan JP, St Hilaire MA, Philips AJK, Loddenkemper T, Kothare SV, McConnell K, Braga-Kenyon P, Ahearn W, Schlesinger A, Potter J, Bird F, Cornish KM, Lockley SW. Sleep patterns predictive of daytime challenging behavior in individuals with low-functioning autism. Autism Research 2018; 11(2):391-403. PMID: 29197172

88. Anderson C, Ftouni S, Ronda JM, Rajaratnam SMW, Czeisler CA, Lockley SW. Self-reported drowsiness and safety outcomes while driving after an extended duration work shift in trainee physicians. Sleep 2018; 41(2) zsx195. PMID: 29281091

89. St. Hilaire MA, Rahman SA, Gooley JJ, Witt-Enderby PA, Lockley SW. Relationship between melatonin and bone resorption rhythms in premenopausal women. Journal of Bone and Mineral Metabolism 2019; 37(1):60-71. PMID: 29318392

90. Abeysuriya RG, Lockley SW, Robinson PA, Postnova S. A unified model of melatonin, 6-sulfatoxymelatonin, and sleep dynamics. Journal of Pineal Research 2018; 64(4):e12474. PMID: 29437238

91. Stone JE, Sletten TL, Magee M, Ganesan S, Mulhall MD, Collins A, Howard M, Lockley SW, Rajaratnam SMW. Temporal dynamics of circadian phase shifting response to consecutive night shifts in healthcare workers: Role of light-dark exposure. Journal of Physiology 2018; 596(12):2381-2395. PMID: 29589871

92. Hull JT, Czeisler CA, Lockley SW. Suppression of melatonin secretion in totally visually blind people by ocular exposure to white light: Clinical characteristics. Ophthalmology 2018; 125(8):1160-1171. PMID: 29625838

93. Postnova S, Lockley SW, Robinson PA. Prediction of cognitive performance and subjective sleepiness using a model of arousal dynamics. Journal of Biological Rhythms 2018; 33(2):203-218. PMID: 29671707

94. Rahman SA, St. Hilaire MA, Gronfier C, Chang AM, Santhi N, Czeisler CA, Klerman EB, Lockley SW. Functional decoupling of melatonin suppression and circadian phase resetting in humans. Journal of Physiology 2018; 596(11):2147-2157. PMID: 29707782

95. Vidafar P, Gooley JJ, Burns AC, Rajaratnam SMW, Rueger M, Van Reen E, Czeisler CA, Lockley SW, Cain SW. Increased vulnerability to attentional failure during acute sleep deprivation in women depends on menstrual phase. Sleep 2018; 41(8). PMID: 29790961

96. Sletten TL, Magee M, Murray JM, Gordon CJ, Lovato N, Kennaway DJ, Gwini SM, Bartlett DJ, Lockley SW, Lack LC, Grunstein RR, Rajaratnam SMW; for the Delayed Sleep on Melatonin (DelSoM) Study Group. Efficacy of melatonin with behavioural sleep-wake scheduling for delayed sleep-wake phase disorder: A double-blind, randomised clinical trial. PLoS Medicine 2018; 15(6):e1002587. PMID: 29912983 PMCID: PMC6005466

97. McMahon WR, Ftouni S, Drummond SPA, Maruff P, Lockley SW, Rajaratnam SMW, Anderson C. The wake maintenance zone shows task dependent changes in cognitive function following one night without sleep. Sleep 2018; 41(10). PMID: 30169703

98. Ogeil RP, Barger LK, Lockley SW, O'Brien CS, Sullivan JP, Qadri S, Lubman DI, Czeisler CA, Rajaratnam SMW. Cross-sectional analysis of sleep-promoting and wake-promoting drug use on health, fatigue-related error and near crashes in police officers. BMJ Open 2018; 8(9):e022041. PMID: 30232109 PMCID:PMC6150149

99. Vandewalle G*, van Ackeren MJ*, Daneault V, Hull JT, Albouy G, Lepore F, Doyon J, Czeisler CA, Dumont M, Carrier J, Lockley SW, Collignon O. Light modulates oscillatory alpha activity in the occipital cortex of totally visually blind individuals with intact non-image-forming photoreception. Scientific Reports 2018; 8(1):16968. PMID: 30446699 PMCID:PMC6240048

100. Watson LA, Phillips AJK, Hosken IT,  McGlashan EM, Anderson C, Lack LC, Lockley SW, Rajaratnam SMW, Cain SW. Increased sensitivity of the circadian system to light in Delayed Sleep-Wake Phase Disorder. Journal of Physiology 2018; 596(24):6249-6261. PMID: 30281150

101. Hanifin JP, Lockley SW, Cecil K, West K, Westa M, Jablonski M, Warfield B, James M, Ayers M, Byrne B, Gerner E, Pineda C, Rollag M, Brainard GC. Randomized trial of polychromatic blue-enriched light for circadian phase shifting, melatonin suppression, and alerting responses. Physiology and Behavior 2019; 198:57-66. PMID: 30296404

102. St. Hilaire MA, Anderson C, Anwar J, Sullivan JP, Cade BE, Flynn-Evans EE, Czeisler CA, Lockley SW; for the Harvard Work Hours Health and Safety Group. Brief (<4 hour) sleep episodes are insufficient for restoring performance in first-year resident physicians working overnight extended-duration work shifts. Sleep 2019; 42(5). PMID: 30794317

103. Grant LK, Ftouni S, Nijagal B, De Souza DP, Tull D, McConville MJ, Rajaratnam SW, Lockley SW, Anderson C. Circadian and wake-dependent changes in human plasma polar metabolites during prolonged wakefulness: A preliminary analysis. Scientific Reports 2019; 9(1):4428. PMID: 30872634 PMCID: PMC6418225

104. Ganesan S, Magee M, Stone JE, Mulhall MD, Collins A, Howard ME, Lockley SW, Rajaratnam SMW, Sletten TL. The impact of shiftwork on sleep, alertness and performance in healthcare workers. Scientific Reports 2019; 9(1):4635. PMID: 30874565 PMCID:   PMC6420632

105. Mulhall MD, Sletten TL, Magee M, Stone JE, Ganesan S, Collins A, Anderson C, Lockley SW, Howard ME, Rajaratnam SMW. Sleepiness and driving events in shift workers: The impact of circadian and homeostatic factors. Sleep 2019; 42(6). PMID: 30882154

106. Blackwell T, Kriesel DR, Vittinghoff E, O’Brien CS, Sullivan JP, Viyaran NC, Rahman SA, Lockley SW, Barger LK, Halblower AC, Poynter SE, Wright Jr KP, Yu PL, Zee PC, Landrigan CP, Czeisler CA, Stone KL; and the ROSTERS Study Group. Design and recruitment of the Randomized Order Safety Trial Evaluating Resident-physician Schedules (ROSTERS) study. Contemporary Clinical Trials 2019; 80:22-33. PMID: 30885799 PMCID: PMC6482052.

107. Chang AM, Duffy JF, Buxton OM, Lane JM, Aeschbach D, Anderson C, Bjonnes AC, Cain SW, Cohen DA, Frayling TM, Gooley JJ, Jones SE, Klerman EB, Lockley SW, Munch M, Rajaratnam SMW, Rueger M, Rutter MK, Santhi N, Scheuermaier K, Van Reen E, Weedon MN, Czeisler CA, Scheer FAJL*, Saxena R*. Chronotype genetic variant in PER2 is associated with intrinsic circadian period in humans. Scientific Reports 2019; 9(1):5350. PMID: 30926824 PMCID: PMC6440993

108. Barger LK, Sullivan JP, Blackwell T, O’Brien CS, St. Hilaire MA, Rahman SA, Phillips AJK, Qadri S, Wright KP, Segar JL, McGuire JK, Vitiello MV, de la Iglesia HO, Poynter SE, Yu PL, Zee PC, Sanderson AL, Halbower AC, Lockley SW, Landrigan CP, Stone KL, Czeisler CA; ROSTERS Study Group. Effects on resident work hours, sleep duration and work experience in a Randomized Order Safety Trial Evaluating Resident-physician Schedules (ROSTERS). Sleep 2019; 42(8). PMID: 31106381

109. Wolkow AP, Barger LK, O’Brien CS, Sullivan JP, Qadri S, Lockley SW, Czeisler CA, Rajaratnam SMW. Associations between sleep disturbances, mental health outcomes and burnout in firefighters, and the mediating role of sleep during overnight work: A cross-sectional study. Journal of Sleep Research 2019; e12869. PMID: 31131535

110. Murray JM, Phillips AJK, Magee M, Sletten TL, Gordon C, Lovato N, Bei B, Bartlett DJ, Kennaway DJ, Lack LC, Grunstein RR, Lockley SW, Rajaratnam SMW; for the Delayed Sleep on Melatonin (DelSoM) Study Group. Sleep regularity is associated with sleep-wake and circadian timing, and mediates daytime function in Delayed Sleep-Wake Phase Disorder. Sleep Medicine 2019; 58:93-101. PMID: 31132578

111. Phillips AJK*, Vidafar P*, Burns AC, McGlashan EM, Anderson C, Rajaratnam SMW, Lockley SW, Cain SW. High sensitivity and interindividual variability in the response of the human circadian system to evening light. Proceedings of the National Academy of Science USA 2019; 116(24):12019-12024. PMID: 31138694 PMCID: PMC6575863

112. Razavi P, Devore EE, Bajaj A, Lockley SW, Figueiro MG, Ricchiuti V, Gauderman WJ, Hankinson SE, Willett WC, Schernhammer E. Shift work, chronotype, and melatonin rhythm in nurses. Cancer Epidemiology, Biomarkers & Prevention 2019; 28(7):1177-1186. PMID: 31142495

113. Booker LA, Sletten TL, Alvaro PK, Barnes M, Collins A, Chai-Coetze CL, Naqvi A, McMahon M, Lockley SW, Rajaratnam SMW, Howard ME. Exploring the associations between shift work disorder, depression, anxiety and sick leave taken amongst nurses. Journal of Sleep Research 2019; e12872. PMID:  31144389

114. Stone JE, Phillips AJK, Ftouni S, Magee M, Howard M, Lockley SW, Sletten TL, Anderson C, Rajaratnam SMW, Postnova S. Generalizability of a neural network model for circadian phase prediction in real-world conditions. Scientific Reports 2019; 9(1):11001. PMID: 31358781

115. Stone JE, Aubert XL, Maass H, Phillips AJK, Magee M, Howard ME, Lockley SW, Rajaratnam SMW, Sletten TL. Application of a limit-cycle oscillator model for prediction of circadian phase in rotating night shift workers. Scientific Reports 2019; 9(1):11032. PMID: 31363110

116. Rahman SA, Grant LK, Gooley JJ, Rajaratnam SMW, Czeisler CA, Lockley SW. Endogenous circadian regulation of female reproductive hormones. Journal of Clinical Endocrinology and Metabolism 2019; 104(12):6049-6059. PMID: 31415086

117. Chua EC, Sullivan JP, Duffy JF, Klerman EB, Lockley SW, Kristal BS, Czeisler CA, Gooley JJ. Classifying attentional vulnerability to total sleep deprivation using baseline features of Psychomotor Vigilance Test performance. Scientific Reports 2019; 9(1):12102. PMID: 31431644 PMCID: PMC6702200

118. Booker LA, Barnes M,  Alvaro P, Collins A, Chai-Coetze CL, McMahon M, Lockley SW, Rajaratnam SMW, Howard ME. Sletten TL. The role of sleep hygiene in the risk of Shift Work Disorder in nurses. Sleep 2019; in press. Oct 22. pii: zsz228. doi: 10.1093/sleep/zsz228. [Epub ahead of print] PMID: 31637435

119. Grant LK, Gooley JJ, St Hilaire MA, Rajaratnam SMW, Brainard GC, Czeisler CA, Lockley SW, Rahman SA. Menstrual phase-dependent differences in neurobehavioral performance: The role of temperature and the progesterone/estradiol ratio. Sleep 2019; in press. Oct 31. pii: zsz227. doi: 10.1093/sleep/zsz227. [Epub ahead of print] PMID: 31670824

120. St. Hilaire MA, Kristal BS, Rahman SA, Sullivan JP, Quackenbush J, Duffy JF, Barger LK, Gooley JJ, Czeisler CA, Lockley SW. Using a single daytime performance test to identify most individuals at high-risk for performance impairment during extended wake. Scientific Reports 2019; 9(1):16681. PMID: 31723161

121. Peterson SA*, Wolkow AP*, Lockley SW, O’Brien CS, Qadri S, Sullivan JP, Czeisler CA, Rajaratnam SMW, Barger LK. Associations between shift work characteristics, shift work schedules, sleep and burnout in North American police officers: a cross-sectional study. BMJ Open 2019; 9(11):e030302. PMID: 31791964

122. Rahman SA, Wright Jr KP, Lockley SW, Czeisler CA, Gronfier C. Characterizing the temporal dynamics of melatonin and cortisol changes in response to nocturnal light exposure. Scientific Reports 2019; 9(1):19720. PMID: 31873098

Chapters and Reviews (2017-date)

Lockley SW, Cohen D, Harper DG, Uchiyama M. Advanced, non-24-hour and irregular sleep/wake rhythm disorders. [Book Chapter]. In: Mansfield DR, Antic N, Rajaratnam SMW, Naughton MT, editors. Sleep Medicine, Research, Australia: IP Communications Pty Ltd; 2017. ISBN: 9780995388710.

Lee CJ, Nolan DM, Lockley SW, Pattison B. Law-based arguments and messages to advocate for later school start time policies in the United States [Review]. Sleep Health 2017; 3(6):486-497. PMID: 29157645

Cappuccio FP, Miller MA, Lockley SW, Rajaratnam SMW. Sleep, health and society: the contribution of epidemiology [Book Chapter]. In: Cappuccio FP, Miller MA, Lockley SW, Rajaratnam SMW, editors. Sleep, health and society: From Aetiology to Public Health (2nd Edition), Oxford, UK: Oxford University Press; 2018; pp. 3-9.

Lockley SW. Principles of sleep-wake regulation [Book Chapter]. In: Cappuccio FP, Miller MA, Lockley SW, Rajaratnam SMW, editors. Sleep, health and society: From Aetiology to Public Health (2nd Edition), Oxford, UK: Oxford University Press; 2018; pp. 10-21.

Spitschan MJ, Stefani O, Blattner P, Gronfier C, Lockley SW, Lucas RJ. How to report light exposure in human chronobiology and sleep research experiments [Tutorial]. Clocks & Sleep 2019; 1(3): 280-289. PMID: 31281903 PMCID: PMC6609447

Vetter C, Phillips AJK, Silva A, Lockley SW, Glickman G. Light me up? Why, when, and how much light we need. SRBR White Papers Series Journal of Biological Rhythms 2019; in press. PMID: 31813350