Neuroscience and psychology of sleep lab (NaPS)
Sleep is critical for both health and cognition. Our lab is developing ways to manipulate sleep in order to maximise its beneficial properties.
We are working on ways to enhance memory, disarm negative emotions, and combat cognitive decline through ageing.
- Understand how neural oscillations in sleep benefit cognition and general health.
- Develop ways to enhance these neural oscillations.
- Investigate the differences between memory replay in REM and SWS.
- Develop machine learning methods to identify neural replay during sleep.
- Understand how memory replay in sleep influences consolidation, and specifically determine how memory replay:
- enhances integration processes
- can be used to enhance creativity
- impacts on emotional content.
Please contact Professor Penny Lewis (preferably attaching a CV) if you are interested in applying for a position in the group.
We are always looking for interns who can dedicate at least five months. We can often pay a small stipend to cover living costs
We are always looking for PhD candidates who are interested in our research area. Please send a CV if you are interested.
The following opportunities are currently available:
We are primarily interested in offline learning during sleep and wakefulness: Our research investigates brain plasticity, focusing specifically on the changes in behavior and neural activity which occur after initial learning.
We are particularly interested in changes occurring while a memory is not being encoded, practised or recalled.
Over the last few years, we have coined the term ‘sleep engineering’ to capture the spirit of what we are doing.
Specifically, we are developing ways to actively manipulate the neural processing that occurs during sleep in order to enhance health and cognition.
This can be done either by directly influencing the neural oscillations in sleep (enhancing some and suppressing others) or by influencing which memories are replayed in sleep. In both cases, the manipulations are usually achieved through the quiet presentation of sounds during sleep.
- Jennifer Roebber
- Elena Schmidt
- Tamas Foldes
- Viviana Greco
Matthias Treder - studied the detection of neural replay in sleep with EEG classifiers and is now a lecturer in Computer Science at Cardiff University.
Suliman Belal - studied the application of multivariate classifiers to sleep EEG data.
Alexia Zoumpoulaki - studied the detection of neural replay in sleep with EEG classifiers and is now a lecturer in Computer Science at Cardiff University.
Simon Durrant - studied the importance of SWS for gist abstraction and integration of new learning into schemas and is now a Lecturer at the University of Lincoln.
Jakke Tamminen - studied the importance of sleep for integration of new learning into existing knowledge and is now a postdoc at Royal Holloway.
Jules Schneider - did a PhD on the potential of auditory closed-loop stimulation to enhance sleep oscillations and overnight memory consolidation.
Hikaru Tsujimura - did a PhD exploring the impact of sleep on the generalisation of facial representations and competition between different identities.
Isabel Hutchison - did a PhD on the impact of direct current stimulation on sleep and memory.
Nora Hennies - did a PhD on the impact of sleep upon the formation of new semantic memories.
James Cousins - did a PhD on the impact of triggered replay during sleep upon overnight memory consolidation.
Scott Cairney - did a PhD on sleep and emotional memory and is now a postdoc at York.
Tia Tsimpanouli - did a PhD on sleep, emotional memory and depression.
- Eichenlaub, J. et al., 2019. The nature of delayed dream incorporation ('dream-lag effect'): personally significant events persist, but not major daily activities or concerns. Journal of Sleep Research 28 (1) e12697. (10.1111/jsr.12697)
- Belal, S. et al. 2018. Identification of memory reactivation during sleep by EEG classification. NeuroImage 176 , pp.203-214. (10.1016/j.neuroimage.2018.04.029)
- Eichenlaub, J. et al., 2018. Incorporation of recent waking-life experiences in dreams correlates with frontal theta activity in REM sleep. Social Cognitive and Affective Neuroscience 13 (6), pp.637-647. (10.1093/scan/nsy041)
- Lewis, P. , Knoblich, G. and Poe, G. 2018. How memory replay in sleep boosts creative problem solving. Trends in Cognitive Sciences 22 (6), pp.491-503. (10.1016/j.tics.2018.03.009)
- Hennies, N. et al., 2017. Cued memory reactivation during SWS abolishes the beneficial effect of sleep on abstraction. Sleep 40 (8)(10.1093/sleep/zsx102)
- Lewis, P. A. et al. 2017. Higher order intentionality tasks are cognitively more demanding. Social Cognitive and Affective Neuroscience 12 (7), pp.1063-1071. (10.1093/scan/nsx034)
- Tamminen, J. , Lambon Ralph, M. A. and Lewis, P. 2017. Targeted memory reactivation of newly learned words during sleep triggers REM-mediated integration of new memories and existing knowledge.. Neurobiology of Learning and Memory 137 , pp.77-82. (10.1016/j.nlm.2016.11.012)
- Cousins, J. N. et al., 2016. Cued reactivation of motor learning during sleep leads to overnight changes in functional brain activity and connectivity. Plos Biology 14 (5) e1002451. (10.1371/journal.pbio.1002451)
- Hennies, N. et al., 2016. Sleep spindle density predicts the effect of prior knowledge on memory consolidation. Journal of Neuroscience 36 (13), pp.3799-3810. (10.1523/JNEUROSCI.3162-15.2016)
- Durrant, S. J. , Cairney, S. A. and Lewis, P. A. 2016. Cross-modal transfer of statistical information benefits from sleep.. Cortex 78 , pp.85-99. (10.1016/j.cortex.2016.02.011)
- Durrant, S. J. et al., 2015. Schema-conformant memories are preferentially consolidated during REM sleep. Neurobiology of Learning and Memory 122 , pp.41-50. (10.1016/j.nlm.2015.02.011)
- van Rijn, E. et al., 2015. The dream-lag effect: selective processing of personally significant events during Rapid Eye Movement sleep, but not during Slow Wave Sleep. Neurobiology of Learning and Memory 122 , pp.98-109. (10.1016/j.nlm.2015.01.009)
- Cairney, S. A. et al., 2015. Complementary roles of slow-wave sleep and rapid eye movement sleep in emotional memory consolidation. Cerebral Cortex 25 (6), pp.1565-1575. (10.1093/cercor/bht349)
- Cousins, J. M. et al., 2014. Cued memory reactivation during slow-wave sleep promotes explicit knowledge of a motor sequence. Journal of Neuroscience 34 (48), pp.15870-15876. (10.1523/JNEUROSCI.1011-14.2014)
- Hennies, N. et al., 2014. Time- but not sleep-dependent consolidation promotes the emergence of cross-modal conceptual representations. Neuropsychologia 63 , pp.1161-123. (10.1016/j.neuropsychologia.2014.08.021)
- Cairney, S. A. et al., 2014. Sleep spindles provide indirect support to the consolidation of emotional encoding contexts. Neuropsychologia 63 , pp.285-292. (10.1016/j.neuropsychologia.2014.09.016)
- Cairney, S. A. et al., 2014. Targeted memory reactivation during slow wave sleep facilitates emotional memory consolidation. Sleep 37 (4), pp.701-707. (10.5665/sleep.3572)
- Tamminen, J. , Lambon Ralph, M. A. and Lewis, P. A. 2013. The role of sleep spindles and slow-wave activity in integrating new information in semantic memory. Journal of Neuroscience 33 (39), pp.15376-15381. (10.1523/JNEUROSCI.5093-12.2013)
- Durrant, S. J. , Cairney, S. A. and Lewis, P. A. 2012. Overnight consolidation aids the transfer of statistical knowledge from the medial temporal lobe to the striatum. Cerebral Cortex -New York- Oxford University Press- 23 (10), pp.2467-2478. (10.1093/cercor/bhs244)
- Powell, J. et al., 2012. Orbital prefrontal cortex volume predicts social network size: an imaging study of individual differences in humans. Proceedings of the Royal Society B: Biological Sciences 283 (1824)(10.1098/rspb.2011.2574)
- Wuerger, S. et al., 2012. Premotor cortex is sensitive to auditory–visual congruence for biological motion. Journal of Cognitive Neuroscience 24 (3), pp.575-587. (10.1162/jocn_a_00173)
- Cairney, S. A. et al., 2011. Sleep and environmental context: interactive effects for memory. Experimental Brain Research 214 , pp.83-92. (10.1007/s00221-011-2808-7)
- Lewis, P. A. et al. 2011. The impact of overnight consolidation upon memory for emotional and neutral encoding contexts. Neuropsychologia 49 (9), pp.2619-2629. (10.1016/j.neuropsychologia.2011.05.009)
- Lewis, P. A. et al. 2011. Ventromedial prefrontal volume predicts understanding of others and social network size. NeuroImage 57 (4), pp.1624-1629. (10.1016/j.neuroimage.2011.05.030)
- Durrant, S. J. et al., 2011. Sleep-dependent consolidation of statistical learning. Neuropsychologia 49 (5), pp.1322-1331. (10.1016/j.neuropsychologia.2011.02.015)
- Javardi, A. H. , Walsh, V. and Lewis, P. A. 2010. Offline consolidation of procedural skill learning is enhanced by negative emotional content. Experimental Brain Research 208 (4), pp.507-517. (10.1007/s00221-010-2497-7)
- Lewis, P. A. , Couch, T. J. and Walker, M. P. 2010. Keeping time in your sleep: overnight consolidation of temporal rhythm. Neuropsychologia 49 (1), pp.115-123. (10.1016/j.neuropsychologia.2010.10.025)
- Powell, J. L. et al., 2010. Orbital prefrontal cortex volume correlates with social cognitive competence. Neuropsychologia 48 (12), pp.3554-3562. (10.1016/j.neuropsychologia.2010.08.004)
- Durrant, S. and Lewis, P. A. 2009. Memory consolidation: tracking transfer with functional connectivity. Current Biology 19 (18), pp.R860-R862. (10.1016/j.cub.2009.08.019)
- Lewis, P. A. and Miall, R. C. 2009. The precision of temporal judgement: milliseconds, many minutes, and beyond. Philosophical Transactions of the Royal Society B: Biological Sciences 364 (1525)(10.1098/rstb.2009.0020)
- Holland, P. and Lewis, P. A. 2007. Emotional memory: selective enhancement by sleep. Current Biology 17 (5), pp.R179-R181. (10.1016/j.cub.2006.12.033)
- Critchley, H. D. et al., 2007. Vagus nerve stimulation for treatment-resistant depression: behavioral and neural effects on encoding negative material. Psychosomatic Medicine -Washington- 69 (1), pp.17-22. (10.1097/PSY.0b013e31802e106d)
- Lewis, P. A. and Miall, R. C. 2006. Remembering the time: a continuous clock. Trends in Cognitive Sciences 10 (9), pp.401-406. (10.1016/j.tics.2006.07.006)
- Lewis, P. A. et al. 2006. Neural correlates of processing valence and arousal in affective words. Cerebral Cortex -New York- Oxford University Press- 17 (3), pp.742-748. (10.1093/cercor/bhk024)
- Lewis, P. A. and Miall, R. C. 2006. A right hemispheric prefrontal system for cognitive time measurement. Behavioural Processes 71 (2-3), pp.226-234. (10.1016/j.beproc.2005.12.009)
- Lewis, P. A. and Walsh, V. 2005. Time perception: components of the brain’s clock. Current Biology 15 (10), pp.R389-R391. (10.1016/j.cub.2005.05.008)
- Lewis, P. A. et al. 2005. Brain mechanisms for mood congruent memory facilitation. NeuroImage 25 (4), pp.1214-1223. (10.1016/j.neuroimage.2004.11.053)
- Lewis, P. A. et al. 2004. Brain activity correlates differentially with increasing temporal complexity of rhythms during initialisation, synchronisation, and continuation phases of paced finger tapping. Neuropsychologia 42 (10), pp.1301-1312. (10.1016/j.neuropsychologia.2004.03.001)
- Lewis, P. A. and Critchley, H. D. 2003. Mood-dependent memory. Trends in Cognitive Sciences 7 (10), pp.431-433. (10.1016/j.tics.2003.08.005)
- Lewis, P. A. et al. 2003. Interval timing in mice does not rely upon the circadian pacemaker. Neuroscience Letters 348 (3), pp.131-134. (10.1016/S0304-3940(03)00521-4)
- Lewis, P. A. and Miall, R. C. 2003. Brain activation patterns during measurement of sub- and supra-second intervals. Neuropsychologia 41 (12), pp.1583-1592. (10.1016/S0028-3932(03)00118-0)
- Lewis, P. A. and Miall, R. C. 2003. Distinct systems for automatic and cognitively controlled time measurement: evidence from neuroimaging. Current Opinion in Neurobiology 13 (2), pp.250-255. (10.1016/S0959-4388(03)00036-9)
- Lewis, P. A. and Miall, R. C. 2002. Brain activity during non-automatic motor production of discrete multi-second intervals. Neuroreport -Oxford- 13 (4), pp.1731-1735.
- Lewis, P. A. 2002. Musical Minds. Trends in Cognitive Sciences 6 (9), pp.364-366. (10.1016/S1364-6613(02)01955-1)
- Lewis, P. A. 2002. Finding the timer. Trends in Cognitive Sciences 6 (5), pp.195-196. (10.1016/S1364-6613(02)01906-X)
- Lewis, P. A. and Walsh, V. 2002. Neuropsychology: Time Out of Mind. Current Biology 12 (1), pp.R9-R11. (10.1016/S0960-9822(01)00638-8)
SolutionSleep (ERC grant on sleep and creativity)
Innovative problem solving is critical for all spheres of organised endeavour, including science and industry, and thus forms the cornerstone of a successful society. Such creative thinking often requires suppression of preconceptions and restructuring of existing knowledge.
Pioneering work has shown that sleep facilitates problem solving, but exactly how, and which sleep characteristics are important, remain to be determined. We know that recent experiences are replayed in sleep, and that in Slow Wave Sleep (SWS) this replay integrates new knowledge with old.
The role of such replay in Rapid Eye Movement (REM) sleep, a stage which is strongly linked to creativity, is unknown. We have proposed BiOtA, a model which combines physiology, behavioural studies, and computational modelling to make testable predictions about the complementary contributions of memory replay in REM and SWS to problem solving. We are testing this model through explicit manipulation of memory replay in sleep.
We are using a very recently developed technique to explicitly trigger memory replay, a pioneering method for quantifying this replay, and cutting-edge approaches for manipulation of neural oscillations during sleep. We expect two key results: first, we will uncover the principles of how memory replay in REM and SWS combines with specific neural oscillations to promote both long-term memory and creative problem solving.
This will involve development of a computational model which will enable optimised experimental design, paving the way for efficient future investigation of how to enhance innovation through manipulation of sleep. Second, we will develop methods for boosting key sleep processes in a selective, targeted manner. Immediate consequences will include a translational project to facilitate everyday problem solving.
Check out the ERCcOMICS Blog which features the ERC SolutionSleep project.
Humanlike Computing (EPSRC grant on AI and sleep)
The media have lately been full of excitement about progress in Artificial Intelligence. Not only can computers now beat humans at Go, and detect cats in YouTube videos, but soon we will have robots in the house, self-driving cars, and many jobs might become automated. Apart from the societal challenges that this revolution will bring, many hurdles are still to be overcome before Artificial Intelligence will obtain truly human-like capabilities.
In particular, current artificial systems might be very good at specific tasks, they cannot easily apply their processing power to other problems. Moreover, in order to become experts in a certain problem these machines often need millions of training examples.
Current AI systems follow a strategy very different from humans and obtain their strength from brute compute power and massive amounts of data rather than by cleverness. This is also the reason why it is hard to communicate with these machines, understand their decisions and instruct them.
The fact that computers use an approach that is so different from that used by humans seriously hinders application of AI to real world applications. The research community is well aware of these issues, and it generally believed that the problem arises because machines don't construct higher level understanding of the problems that they are solving. How this should be addressed is however not Clear.
In humans and animals sleep plays an important role in creating high level representations. During sleep, the brain consolidates information, rearranges it, finds links between different types of knowledge, reformulates problems, and comes up with creative solutions. Most people have experienced this at some point - as they feel better able to solve a problem after a good night of sleep.
It is only very recently that researchers have become able to manipulate the processes that go on during sleep, and thereby pick apart the roles of the various sleep phases play and the reason why the sleep phases are ordered in a particular way.
In this project, we are examining how to processes occurring during sleep can be mimicked in computational models, and thereby open the possibility to build more human-like artificial systems.
We hold a Journal Club on sleep and memory at 15:00 on Wednesdays.
- Replay@CUBRIC 2018 (13-14 September 2018, Cardiff)
- World Sleep Day Celebration (8 March 2018, Cardiff)
- Creative Minds Summer School (July 2017, Budapest)
- Replay@CUBRIC 2017 (8 May 2017, Cardiff)
Past guest lectures
- Francesca Siclari – ‘The EEG correlates of dream consciousness' - August 2018
- Michele Bellesi – ‘Enhancing sleep slow waves using acoustic stimuli' – April 2018
- Nicolai Axmacher – ‘Engram patterns in intracranial EEG and fMRI’ – October 2017
- Hong-Viet Ngo – ‘Brain stimulation during sleep: Targeting EEG oscillations to investigate the memory function of sleep’ – July 2017
- Lucia Talamini –‘Closed loop stimulation of sleep’ – May 2017
- Martin Willis – 'Sleeping before the Neurosciences: Science, Medicine and Culture’ – April 2017
- Gordon Feld ‘Neurochemical mechanisms of sleep’s beneficial effect on memory processes’ – 6 February 2017
Features and talks
- BBC Reel feature on sleep art
- BBC feature on our work
- TEDx talk on Sleep Engineering (over a million views)
- The Secret World of Sleep: The Surprising Science of the Mind at Rest
- Spindles: Stories from the Science of Sleep
- 'ERCcOMICS' Blog featuring the SolutionSleep ERC-funded project on sleep and creativity
- BBC Idea: The extraordinary human brain - Can we manipulate our sleep?
- Radio New Zealand: The Secret World of Sleep
- Brain Science Podcast: Sleep Science with Penny Lewis
- Australian Broadcasting Corporation: All in the Mind – the mind at rest
- Constant Wonder: Engineering Sleep, Flea Circus, Ghost Town, Ice King
- BBC Radio 4: Science of Dreaming
News and magazine articles
- Donna Moderna (Italian-language magazine): Dormi e sarai più creativa
- Financial Times: Why we dream
- The Atlantic: A New Theory Linking Sleep and Creativity by Ed Yong
- Parade: 5 things you didn’t know about sleep
- Daily Telegraph: Top tips for better sleep
- Top Sante: Ask the sleep expert
- BBC Focus: How sleep can make you smarter
- Candis: The secrets of sleep
- Huffington Post: Advice on how to get more rest