Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Sleep inspires insight


Insight denotes a mental restructuring that leads to a sudden gain of explicit knowledge allowing qualitatively changed behaviour1,2. Anecdotal reports on scientific discovery suggest that pivotal insights can be gained through sleep3. Sleep consolidates recent memories4,5,6 and, concomitantly, could allow insight by changing their representational structure. Here we show a facilitating role of sleep in a process of insight. Subjects performed a cognitive task requiring the learning of stimulus–response sequences, in which they improved gradually by increasing response speed across task blocks. However, they could also improve abruptly after gaining insight into a hidden abstract rule underlying all sequences. Initial training establishing a task representation was followed by 8 h of nocturnal sleep, nocturnal wakefulness, or daytime wakefulness. At subsequent retesting, more than twice as many subjects gained insight into the hidden rule after sleep as after wakefulness, regardless of time of day. Sleep did not enhance insight in the absence of initial training. A characteristic antecedent of sleep-related insight was revealed in a slowing of reaction times across sleep. We conclude that sleep, by restructuring new memory representations, facilitates extraction of explicit knowledge and insightful behaviour.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Figure 1: Task and experimental design.
Figure 2: Effects of sleep and wakefulness on the occurrence of insight.
Figure 3: Reaction time analysis.


  1. Köhler, W. Gestalt Psychology: An Introduction to New Concepts in Modern Psychology (Liveright, New York, 1947)

    Google Scholar 

  2. Sternberg, R. J. & Davidson, J. E. The Nature of Insight (Bradford Books/MIT Press, Cambridge, MA, 1995)

    Google Scholar 

  3. Mazzarello, P. What dreams may come? Nature 408, 523 (2000)

    Article  ADS  CAS  PubMed  Google Scholar 

  4. Maquet, P. The role of sleep in learning and memory. Science 294, 1048–1052 (2001)

    Article  ADS  CAS  PubMed  Google Scholar 

  5. Smith, C. Sleep states and memory processes. Behav. Brain Res. 69, 137–145 (1995)

    Article  ADS  CAS  PubMed  Google Scholar 

  6. Buzsáki, G. Memory consolidation during sleep: a neurophysiological perspective. J. Sleep Res. 7 (Suppl. 1), 17–23 (1998)

    Article  PubMed  Google Scholar 

  7. Pavlides, C. & Winson, J. Influences of hippocampal place cell firing in the awake state on the activity of these cells during subsequent sleep episodes. J. Neurosci. 9, 2907–2918 (1989)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Wilson, M. A. & McNaughton, B. L. Reactivation of hippocampal ensemble memories during sleep. Science 265, 676–679 (1994)

    Article  ADS  CAS  PubMed  Google Scholar 

  9. Maquet, P. et al. Experience-dependent changes in cerebral activation during human REM sleep. Nature Neurosci. 3, 831–836 (2000)

    Article  CAS  PubMed  Google Scholar 

  10. Stickgold, R., Hobson, J. A., Fosse, R. & Fosse, M. Sleep, learning, and dreams: off-line memory reprocessing. Science 294, 1052–1057 (2001)

    Article  ADS  CAS  PubMed  Google Scholar 

  11. Fishbein, W. Disruptive effects of rapid eye movement sleep deprivation on long-term memory. Physiol. Behav. 6, 279–282 (1971)

    Article  CAS  PubMed  Google Scholar 

  12. Gais, S., Plihal, W., Wagner, U. & Born, J. Early sleep triggers memory for early visual discrimination skills. Nature Neurosci. 3, 1335–1339 (2000)

    Article  CAS  PubMed  Google Scholar 

  13. Plihal, W. & Born, J. Effects of early and late nocturnal sleep on declarative and procedural memory. J. Cogn. Neurosci. 9, 534–547 (1997)

    Article  CAS  PubMed  Google Scholar 

  14. Wagner, U., Gais, S. & Born, J. Emotional memory formation is enhanced across sleep intervals with high amounts of rapid eye movement sleep. Learn. Mem. 8, 112–119 (2001)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. McNaughton, B. L., et al. in Sleep and Brain Plasticity (eds Maquet, P., Stickgold, R. & Smith, C.) 225–246 (Oxford Press, Oxford, UK, 2003)

    Book  Google Scholar 

  16. Thurstone, L. L. & Thurstone, T. G. Factorial studies of intelligence. Psychometr. Monogr. 2, 94 (1941)

    MATH  Google Scholar 

  17. Frensch, P., et al. in Attention and Implicit Learning (ed. Jiménez, L.) 335–366 (John Benjamins, Amsterdam/Philadelphia, 2002)

    Google Scholar 

  18. Rose, M., Haider, H., Weiller, C. & Büchel, C. The role of medial temporal lobe structures in implicit learning: an event-related FMRI study. Neuron 36, 1221–1231 (2002)

    Article  CAS  PubMed  Google Scholar 

  19. Epstein, R., Kirshnit, C. E., Lanza, R. P. & Rubin, L. C. ‘Insight’ in the pigeon: antecedents and determinants of an intelligent performance. Nature 308, 61–62 (1984)

    Article  ADS  CAS  PubMed  Google Scholar 

  20. Durso, F. T., Rea, C. B. & Dayton, T. Graph-theoretic confirmation of restructuring during insight. Psychol. Sci. 5, 94–98 (1994)

    Article  Google Scholar 

  21. Jiménez, L., Méndez, C. & Cleeremans, A. Comparing direct and indirect measures of sequence learning. J. Exp. Psychol. Learn. Mem. Cogn. 22, 948–969 (1996)

    Article  Google Scholar 

  22. Cartwright, R. D. Problem solving: waking and dreaming. J. Abnorm. Psychol. 83, 451–455 (1974)

    Article  CAS  PubMed  Google Scholar 

  23. Horne, J. A. Sleep loss and “divergent” thinking ability. Sleep 11, 528–536 (1988)

    Article  CAS  PubMed  Google Scholar 

  24. Walker, M. P., Liston, C., Hobson, J. A. & Stickgold, R. Cognitive flexibility across the sleep-wake cycle: REM-sleep enhancement of anagram problem solving. Brain Res. Cogn. Brain Res. 14, 317–324 (2002)

    Article  PubMed  Google Scholar 

  25. Fischer, S., Hallschmid, M., Elsner, A. L. & Born, J. Sleep forms memory for finger skills. Proc. Natl Acad. Sci. USA 99, 11987–11991 (2002)

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  26. Clark, R. E. & Squire, L. R. Classical conditioning and brain systems: the role of awareness. Science 280, 77–81 (1998)

    Article  ADS  CAS  PubMed  Google Scholar 

  27. Luo, J. & Niki, K. Function of hippocampus in “insight” of problem solving. Hippocampus 13, 316–323 (2003)

    Article  PubMed  Google Scholar 

  28. McIntosh, A. R., Rajah, M. N. & Lobaugh, N. J. Functional connectivity of the medial temporal lobe relates to learning and awareness. J. Neurosci. 23, 6520–6528 (2003)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. McClelland, J. L., McNaughton, B. L. & O'Reilly, R. C. Why there are complementary learning systems in the hippocampus and neocortex: insights from the successes and failures of connectionist models of learning and memory. Psychol. Rev. 102, 419–457 (1995)

    Article  PubMed  Google Scholar 

  30. Rechtschaffen, A. & Kales, A. A Manual of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects (NIH Publ. No. 204, Maryland, 1968)

    Google Scholar 

Download references


We thank S. Sabban, C. Benedict, M. Degirmenci, L. Hecking, A. Otterbein, and M. Rose for their assistance. This work was supported by grants from the Deutsche Forschungsgemeinschaft to J.B. and R.V.

Author information

Authors and Affiliations


Corresponding authors

Correspondence to Ullrich Wagner or Jan Born.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wagner, U., Gais, S., Haider, H. et al. Sleep inspires insight. Nature 427, 352–355 (2004).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing