Publications

Published papers

2025

• Shaif, N.A.S., Lim, J., Reffi, A., Chee, M.W.L., Massar, S.A.A., Ong, J.L. (2025).  Sleep Reactivity Amplifies the Impact of Pre‐Sleep Cognitive Arousal on Sleep Disturbances. Journal of Sleep Research, e70220.

• Chun Siong Soon, Xin Yu Chua, Ruth L F Leong, Ju Lynn Ong, Stijn A A Massar, Shuo Qin, Kyra H M Chong, Jukka-Pekka Onnela, Michael W L Chee, A Longitudinal Study of Sleep in University Freshmen: Facilitating and Impeding Factors, Sleep, 2025; [Link] 

• Mohapatra, L., Cabral, R., Bhatnagar, M. et al. Glucoregulatory status modulates acute cognitive effects of repeated low-glycaemic snack consumption in older adults: a decentralized randomized controlled trial. Eur J Nutr 64, 189 (2025).  [Link] 

• Pu, Z., Ng, A. S. C., Suh, S., Chee, M. W. L., & Massar, S. A. A. (2025). Failing to Plan: Bedtime Planning, Bedtime Procrastination, and Objective Sleep in University Students. Sleep Medicine, 106556. [Link] 

2024

• Massar, S.A.A., Chua, X.Y., ..., Chee, M.W.L. (2024) Sleep, Well-Being, and Cognition in Medical Interns on a Float or Overnight Call Schedule. JAMA Network Open. [Link]

2023

• Ng, A.S.C., Massar, S.A.A., Bei, B., & Chee, M.W.L. (2023) Assessing 'readiness' by tracking fluctuations in daily sleep duration and its influence on mood motivation and sleepiness. Sleep Med. [Link]

• Massar, S.A.A., Ong J.L., Lau, T.Y., Ng, B.K., Chan, L.F., Koek, D., Cheong, K. and Chee, M.W., Working-from-Home persistently Influences Sleep and Physical Activity 2 Years After the Covid-19 Pandemic onset: A longitudinal sleep tracker and electronic diary-based study. Frontiers in Psychology, 14, p.1851. [Link]

• Massar, S.A.A., Ong, J.L., & Chee, M.W.L. (2023). Impact of Covid-19 Mobility Restrictions on Sleep and Well-Being. In: BaHammam, A., Pandi-Perumal, S.R., Jahrami, H. (eds) COVID-10 and Sleep: A Global Outlook. Progress in Sleep Research. [Link]

• Ong, J. L., Massar, S.A.A., ..., & Chee, M. W. L. (2023). A Randomised Controlled Trial of a Digital, Small Incentive-based Intervention for Working Adults with Short Sleep, Sleep, zsac315. [Link] 

2022

• Pu, Z., Leong, R. L. F., Chee, M. W. L., & Massar, S. A. A. (2022). Bedtime procrastination and chronotype differentially predict adolescent sleep on school nights and non-school nights. Sleep Health, 8(6): 640-647. [Link] 

• Lau, T, Ong, J. L., ..., Massar, S. A. A., & Chee, M. W. L. (2022). Minimum number of nights for reliable estimation of habitual sleep using a consumer sleep tracker. SLEEP Advances, 3(1), zpac026. [Link]

• Chen, C., Long, R., Pu, .Z., &  Massar, S. A. A. (2022). Limited evidence for enhanced working memory performance and effort allocation in the face of loss versus gain incentives: A preregistered (non) replication. Psychophysiology, 59(11), e14083. [PDF]

• Teng, J., Massar, S. A. A., & Lim, J. (2022). Inter-relationships between changes in stress, mindfulness, and dynamic functional connectivity. Scientific reports. [Link]

• Massar,  S. A. A., Ng,  A. S. C., Soon, C. S., Ong,  J. L., Chua, X. Y., Chee, N. I. Y. N. , Lee, T. S., & Chee, M. W. L. (2022). Reopening after lockdown: the influence of working-from-home and digital device use on sleep, physical activity, and wellbeing following COVID-19 lockdown and reopening. SLEEP. [Link]

2021

• Massar,  S. A. A., Chua, X. Y., Soon, C. S., Ng,  A. S. C.,  Ong,  J. L., Chee, N. I. Y. N. , Lee, T. S., Ghosh, A. & Chee, M. W. L. (2021). Trait-like nocturnal sleep behavior identified by combining wearable, phone-use, and self-report data. NPJ Digital Medicine, 4, 90. [Link]

• Massar, S. A. A. (2021). Sleep loss and risk-taking: new findings in a field that needs more clarity, SLEEP, 44(4), zsab013.  [Link]

• Ong, J. L., Lau, T. Y., Massar, S. A. A., Chong, Z. T., Ng, B. K. L., Koek, D., ... & Chee, M. W. L. (2021). COVID-19 Related Mobility Reduction: Heterogenous Effects on Sleep and Physical Activity Rhythms. SLEEP,  44 (2), zsaa179. [Link] [Supplement]

2020

• Massar, S. A. A., Pu, Z., Chen, C., & Chee, M. W. (2020). Losses Motivate Cognitive Effort More Than Gains in Effort-Based Decision Making and Performance. Frontiers in Human Neuroscience, 14, 287. [Link] [Supplement] [Data/Code]

• Massar, S. A. A., Poh, J. H., Lim, J., & Chee, M. W. (2020). Dissociable influences of implicit temporal expectation on attentional performance and mind wandering. Cognition, 199, 104242. [PDF] [Supplement] [Data/Code]

• Lin, J., Massar, S. A. A., & Lim, J. (2020). Trait mindfulness moderates reactivity to social stress in an all-male sample. Mindfulness, 11, 2140–2149. [PDF] [Data]

2019

• Teng, J., Massar, S. A. A., Tandi, J., & Lim, J. (2019). Pace yourself: Neural activation and connectivity changes over time vary by task type and pacing. Brain and cognition, 137, 103629. [Link]

• Sasmita, K., Massar, S. A. A., Lim, J., & Chee, M. W. (2019). Reward motivation normalises temporal attention after sleep deprivation. Journal of sleep research, 28(4), e12796. [PDF] 

• Massar, S. A. A., Lim, J., & Huettel, S. A. (2019). Sleep deprivation, effort allocation and performance. In Progress in brain research (Vol. 246, pp. 1-26). [PDF] 

• Poh, J. H., Massar, S. A. A., Jamaluddin, S. A., & Chee, M. W. (2019). Reward supports flexible orienting of attention to category information and influences subsequent memory. Psychonomic bulletin & review, 26(2), 559-568. [PDF] [Supplement] [Data/Code]

• Massar, S. A. A., & Chee, M. W. (2019). Sleep and delay discounting: is insufficient sleep a cause or a manifestation of short-sighted choice?. Sleep, 42(4), zsz005. [Link]

• Massar, S. A. A., Lim, J., Sasmita, K., & Chee, M. W. (2019). Sleep deprivation increases the costs of attentional effort: Performance, preference and pupil size. Neuropsychologia, 123, 169-177. [HTML] [Supplement]

2018

• Wong, K. F., Massar, S. A. A., Chee, M. W., & Lim, J. (2018). Towards an objective measure of mindfulness: replicating and extending the features of the breath-counting task. Mindfulness, 9(5), 1402-1410. [Link]

• Lim, J., Teng, J., Patanaik, A., Tandi, J., & Massar, S. A. A. (2018). Dynamic functional connectivity markers of objective trait mindfulness. Neuroimage, 176, 193-202. [Link] [Preprint]

• Massar, S. A. A., Sasmita, K., Lim, J., & Chee, M. W. (2018). Motivation alters implicit temporal attention through sustained and transient mechanisms: A behavioral and pupillometric study. Psychophysiology, 55(12), e13275. [PDF]

• Massar, S. A. A., Csathó, Á., & Van der Linden, D. (2018). Quantifying the motivational effects of cognitive fatigue through effort-based decision making. Frontiers in psychology, 9, 843. [Link]

2017

• Massar, S. A. A., Liu, J. C., Mohammad, N. B., & Chee, M. W. (2017). Poor habitual sleep efficiency is associated with increased cardiovascular and cortisol stress reactivity in men. Psychoneuroendocrinology, 81, 151-156. [PDF]

2016

• Massar, S. A. A., Lim, J., Sasmita, K., & Chee, M. W. (2016). Rewards boost sustained attention through higher effort: A value-based decision making approach. Biological Psychology, 120, 21-27. [Link]

2015

• Massar, S. A. A., & Chee, M. W. (2015). Preserved calibration of persistence based on delay‐timing distribution during sleep deprivation. Journal of sleep research, 24(6), 673-679. [PDF]

• Massar, S. A. A., Libedinsky, C., Weiyan, C., Huettel, S. A., & Chee, M. W. (2015). Separate and overlapping brain areas encode subjective value during delay and effort discounting. Neuroimage, 120, 104-113. [Link]

• Liu, J. C., Verhulst, S., Massar, S. A. A., & Chee, M. W. (2015). Sleep deprived and sweating it out: the effects of total sleep deprivation on skin conductance reactivity to psychosocial stress. Sleep, 38(1), 155-159. [Link]

2014

• Massar, S. A. A., Kenemans, J. L., & Schutter, D. J. (2014). Resting-state EEG theta activity and risk learning: sensitivity to reward or punishment?. International Journal of Psychophysiology, 91(3), 172-177. [Link]

2013

• Libedinsky, C., Massar, S. A. A., Ling, A., Chee, W., Huettel, S. A., & Chee, M. W. (2013). Sleep deprivation alters effort discounting but not delay discounting of monetary rewards. Sleep, 36(6), 899-904. [Link]

2012 - Earlier

• Heitland, I., Oosting, R. S., Baas, J. M. P., Massar, S. A. A., Kenemans, J. L., & Böcker, K. B. E. (2012). Genetic polymorphisms of the dopamine and serotonin systems modulate the neurophysiological response to feedback and risk taking in healthy humans. Cognitive, Affective, & Behavioral Neuroscience, 12(4), 678-691.  [Link]

• Massar, S. A. A., Rossi, V., Schutter, D. J. L. G., & Kenemans, J. L. (2012). Baseline EEG theta/beta ratio and punishment sensitivity as biomarkers for feedback-related negativity (FRN) and risk-taking. Clinical Neurophysiology, 123(10), 1958-1965. [PDF]

• Massar, S. A. A., Mol, N. M., Kenemans, J. L., & Baas, J. M. (2011). Attentional bias in high-and low-anxious individuals: evidence for threat-induced effects on engagement and disengagement. Cognition & emotion, 25(5), 805-817. [Link]

• Massar, S. A. A., Wester, A. E., Volkerts, E. R., & Kenemans, J. L. (2010). Manipulation specific effects of mental fatigue: evidence from novelty processing and simulated driving. Psychophysiology, 47(6), 1119-1126. [Link]

• van der Linden, D., Massar, S. A. A., Schellekens, A. F., Ellenbroek, B. A., & Verkes, R. J. (2006). Disrupted sensorimotor gating due to mental fatigue: preliminary evidence. International journal of psychophysiology, 62(1), 168-174. [Link]