Chemosensory Perception

, Volume 7, Issue 3–4, pp 140–146 | Cite as

Olfactory Stimulation During Sleep Can Reactivate Odor-Associated Images

  • Michael Schredl
  • Leonie Hoffmann
  • J. Ulrich Sommer
  • Boris A. Stuck



Research has indicated that olfactory stimuli presented during sleep might reactivate memories that are associated with this odor. The present study is the first to examine whether learned associations between odor and images can be reactivated during sleep.


Sixteen healthy, normosmic volunteers underwent a balanced learning task in which pictures of rural scenes and pictures of city scenes were associated with hydrogen sulfide (smell of rotten eggs) or phenyl ethyl alcohol (smell of roses) in the evening in a crossover design. During the subsequent night, they were stimulated with olfactory stimuli (hydrogen sulfide, phenyl ethyl alcohol, and neutral) during REM periods. Participants were awakened 1 min after the stimulation and dream reports were elicited.


The olfactory congruent stimuli significantly increased the probability of dreams about rural scenes, whereas the same effect was not found for city scenes.


As these findings support the hypothesis of reactivation during sleep, it would be very interesting to study the effect of dreams as a tool to measure reactivation of task material on sleep-dependent memory consolidation.


Olfactory stimulation Dream content Sleep-dependent memory consolidation 


Compliance with Ethics Requirements

Conflict of Interest

Michael Schredl declares that he has no conflict of interest.

Leonie Hoffmann declares that she has no conflict of interest.

J. Ulrich Sommer declares that he has no conflict of interest.

Boris A. Stuck declares that he has no conflict of interest.

All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008 (5). Informed consent was obtained from all patients for being included in the study.


  1. Arzi A, Sela L, Green A, Givaty G, Dagan Y, Sobel N (2010) The influence of odorants on respiratory patterns in sleep. Chem Senses 35:31–40CrossRefGoogle Scholar
  2. Arzi A, Shedlesky L, Ben-Shaul M, Nasser K, Oksenberg A, Hairston IS, Sobel N (2012) Humans can learn new information during sleep. Nat Neurosci 15:1460–1465. doi: 10.1038/nn.3193 CrossRefGoogle Scholar
  3. Bastuji H, Garcia-Larrea L (1999) Evoked potentials as a tool for the investigation of human sleep. Sleep Med Rev 3:23–45CrossRefGoogle Scholar
  4. Bradley MM, Lang PJ (2007) The International Affective Picture System (IAPS) in the study of emotion and attention. In: Coan JA, Allen JJB (eds) Handbook of emotion elicitation and assessment. Oxford University Press, New York, pp 29–46Google Scholar
  5. Carskadon MA, Herz RS (2004) Minimal olfactory perception during sleep: why odor alarms will not work for humans. Sleep 27:402–405Google Scholar
  6. De Koninck J, Prevost F, Lortie-Lussier M (1996) Vertical inversion of the visual field and REM sleep mentation. J Sleep Res 5:16–20CrossRefGoogle Scholar
  7. Deuker L et al (2013) Memory consolidation by replay of stimulus-specific neural activity. J Neurosci 33:19373–19383CrossRefGoogle Scholar
  8. Diekelmann S, Wilhelm I, Born J (2009) The whats and whens of sleep-dependent memory consolidation. Sleep Med Rev 13:309–321CrossRefGoogle Scholar
  9. Erlacher D, Schredl M (2010) Practicing a motor task in a lucid dream enhances subsequent performance: a pilot study. Sport Psychol 24:157–167Google Scholar
  10. Gottfried JA (2006) Smell: central nervous processing. Adv Otorhinolaryngol 63:44–69. doi: 10.1159/000093750 Google Scholar
  11. Hartmann E (2011) Continuity? Yes, emotional continuity. Int J Dream Res 4:77Google Scholar
  12. Hummel T, Sekinger B, Wolf SR, Pauli E, Kobal G (1997) ‘Sniffin’ sticks’: olfactory performance assessed by the combined testing of odor identification, odor discrimination and olfactory threshold. Chem Senses 22:39–52CrossRefGoogle Scholar
  13. Iber C, American Academy of Sleep Medicine (2007) The AASM manual for the scoring of sleep and associated events : rules, terminology, and technical specifications. American Academy of Sleep Medicine, WestchesterGoogle Scholar
  14. Kobal G et al (2000) Multicenter investigation of 1,036 subjects using a standardized method for the assessment of olfactory function combining tests of odor identification, odor discrimination, and olfactory thresholds. Eur Arch Otorhinolaryngol 257:205–211CrossRefGoogle Scholar
  15. McCormick DA, Bal T (1997) Sleep and arousal: thalamocortical mechanisms. Annu Rev Neurosci 20:185–215. doi: 10.1146/annurev.neuro.20.1.185 CrossRefGoogle Scholar
  16. Nielsen TA (2000) A review of mentation in REM and NREM sleep: “covert” REM sleep as a possible reconciliation of two opposing models. Behav Brain Sci 23:851–866CrossRefGoogle Scholar
  17. Rasch B, Buchel C, Gais S, Born J (2007) Odor cues during slow-wave sleep prompt declarative memory consolidation. Science 315:1426–1429CrossRefGoogle Scholar
  18. Saint-Denys H (1982) Dreams and how to guide them (original: 1867). Duckworth, LondonGoogle Scholar
  19. Schredl M (2003) Continuity between waking and dreaming: a proposal for a mathematical model. Sleep Hypn 5:38–52Google Scholar
  20. Schredl M (2008) Traum. Reinhardt/UTB, MünchenGoogle Scholar
  21. Schredl M (2013) Studying the relationship between dreaming and sleep-dependent memory processes: methodological challenges. Behav Brain Sci 36:628–629. doi: 10.1017/S0140525X13001428 CrossRefGoogle Scholar
  22. Schredl M, Erlacher D (2010) Is sleep-dependent memory consolidation of a visuo-motor task related to dream content? Int J Dream Res 3:74–79Google Scholar
  23. Schredl M, Reinhard I (2009–2010) The continuity between waking mood and dream emotions: direct and second-order effects. Imagin Cogn Pers 29:271–282Google Scholar
  24. Schredl M, Burchert N, Grabatin Y (2004) The effect of training on interrater reliability in dream content analysis. Sleep Hypn 6:139–144Google Scholar
  25. Schredl M, Atanasova D, Hörmann K, Maurer JT, Hummel T, Stuck BA (2009) Information processing during sleep: the effect of olfactory stimuli on dream content and dream emotions. J Sleep Res 18:285–290CrossRefGoogle Scholar
  26. Schredl M, Sahin V, Schäfer G (1998) Gender differences in dreams: do they reflect gender differences in waking life? Personality and Individual Differences, 25:433–442Google Scholar
  27. Smith DV, Shepherd GM (2003) Chemical senses: taste and olfaction. In: Squire LR (ed) Fundamental neuroscience, 2nd edn. Academic, Amsterdam, pp 631–666Google Scholar
  28. Strauch I, Meier B (1996) In search of dreams: results of experimental dream research. State University of New York Press, AlbanyGoogle Scholar
  29. Stuck BA, Weitz H, Hörmann K, Maurer JT, Hummel T (2006) Chemosensory event-related potentials during sleep—a pilot study. Neurosci Lett 406:222–226CrossRefGoogle Scholar
  30. Stuck BA, Stieber K, Frey S, Freiburg C, Hörmann K, Maurer JT, Hummel T (2007) Arousal responses to olfactory or trigeminal stimulation during sleep. Sleep 30:506–510Google Scholar
  31. Trotter K, Dallas K, Verdone P (1988) Olfactory stimuli and their effects on REM dreams. Psychiatr J Univ Ott 13:94–96Google Scholar
  32. Wagner U, Gais S, Born J (2001) Emotional memory formation is enhanced across sleep intervals with high amounts of rapid eye movement sleep. Learn Mem 8:112–119CrossRefGoogle Scholar
  33. Wamsley EJ, Tucker M, Payne JD, Benavides JA, Stickgold R (2010) Dreaming of a learning task is associated with enhanced sleep-dependent memory consolidation. Curr Biol 20:850–855CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Michael Schredl
    • 1
    • 3
  • Leonie Hoffmann
    • 2
  • J. Ulrich Sommer
    • 2
  • Boris A. Stuck
    • 2
  1. 1.Sleep Laboratory, Central Institute of Mental HealthMedical Faculty Mannheim/Heidelberg UniversityMannheimGermany
  2. 2.Department of Otorhinolaryngology, Head and Neck SurgeryUniversity Hospital MannheimMannheimGermany
  3. 3.Schlaflabor, Zentralinstitut für Seelische GesundheitMannheimGermany

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