Display options
Share it on

Front Neurol. 2012 Jul 11;3:109. doi: 10.3389/fneur.2012.00109. eCollection 2012.

The effects of pre-sleep learning on sleep continuity, stability, and organization in elderly individuals.

Frontiers in neurology

F Conte, G Carobbi, B M Errico, G Ficca

Affiliations

  1. Department of Psychology, University of Naples II Caserta, Italy.

PMID: 22798956 PMCID: PMC3394199 DOI: 10.3389/fneur.2012.00109

Abstract

Several studies have consistently shown that pre-sleep learning is associated to changes of sleep structure. Whereas previous research has mainly focused on sleep states, namely REM and NREM amount, very little attention has been paid to the hypothesis that pre-sleep learning might improve sleep continuity, stability, and cyclic organization, which are often impaired in aging. Thus, aim of this research was to assess, in a sample of 18 healthy elderly subjects, whether a memory task administered at bedtime would determine changes in any sleep parameter, with special regard to sleep continuity, stability, and organization. To this purpose, a baseline sleep (BL), i.e., a normal sleep with 9-h time in bed (TIB), was compared to a post-training sleep (TR), with the same TIB but preceded by an intensive training session. For the latter, a verbal declarative task was used, consisting in learning paired-word lists, rehearsed, and recalled for three times in a row. To control for individual learning abilities, subjects were administered several sets of lists with increasing difficulty, until they reached an error rate ≥20% at third recall. Relative to BL, TR shows a significant reduction in the frequency of brief awakenings, arousals, state transitions, "functional uncertainty" (FU) periods, and in the percentage of time in FU over total sleep time (TST). A significant increase in the number of complete cycles, total cycle time (TCT), and TCT/TST proportion was also found. All these changes are evenly distributed over the sleep episode. No sleep stage measure display significant changes, apart from a slight reduction in the percentage of Stage 1. Scores at retest are negatively correlated with both the frequency of arousals and of state transitions. Our data suggest that pre-sleep learning can yield a beneficial re-organizing effect on elderlies' sleep quality. The inverse correlation between recall scores and the measures of sleep continuity and stability provides further support to the role of these features in memory processes.

Keywords: NREM-REM cycles; aging; arousals; learning; memory consolidation; sleep continuity; sleep organization; sleep stability

References

  1. Psychiatry Res. 1989 May;28(2):193-213 - PubMed
  2. J Clin Sleep Med. 2008 Aug 15;4(4):349-55 - PubMed
  3. Sleep. 1999 May 1;22 Suppl 2:S366-72 - PubMed
  4. J Am Geriatr Soc. 2007 Nov;55(11):1853-66 - PubMed
  5. Aging (Milano). 1998 Dec;10(6):445-8 - PubMed
  6. Int J Neurosci. 1990 May;52(1-2):29-37 - PubMed
  7. Sleep. 2001 Aug 1;24(5):565-77 - PubMed
  8. Annu Int Conf IEEE Eng Med Biol Soc. 2010;2010:5391-4 - PubMed
  9. Curr Biol. 2010 Aug 10;20(15):R626-7 - PubMed
  10. Psychiatry Clin Neurosci. 2001 Jun;55(3):305-10 - PubMed
  11. Sleep. 1993 Jan;16(1):40-81 - PubMed
  12. J Psychiatr Res. 1975 Nov;12(3):189-98 - PubMed
  13. Sleep Med Rev. 2012 Feb;16(1):27-45 - PubMed
  14. Electroencephalogr Clin Neurophysiol. 1998 Dec;107(6):439-50 - PubMed
  15. Hum Neurobiol. 1982;1(3):195-204 - PubMed
  16. Sleep Med. 2004 May;5(3):225-30 - PubMed
  17. J Sleep Res. 2000 Mar;9(1):27-34 - PubMed
  18. Physiol Behav. 1991 Dec;50(6):1153-9 - PubMed
  19. Sleep Med. 2010 Sep;11(8):791-8 - PubMed
  20. J Psychiatr Res. 1974 Oct;10(3-4):283-306 - PubMed
  21. Proc Natl Acad Sci U S A. 2011 Aug 9;108(32):13305-10 - PubMed
  22. Sleep. 2005 Feb;28(2):220-30 - PubMed
  23. Brain Res Bull. 2003 Dec 15;62(2):143-50 - PubMed
  24. Biol Psychiatry. 1992 May 1;31(9):866-80 - PubMed
  25. Psychoneuroendocrinology. 2011 Oct;36(9):1361-9 - PubMed
  26. Sleep Med. 2001 Nov;2(6):537-53 - PubMed
  27. Behav Brain Res. 2000 Jul;112(1-2):159-63 - PubMed
  28. Eur J Neurosci. 2006 May;23(10):2739-48 - PubMed
  29. Acta Neurol Belg. 1997 Jun;97(2):118-22 - PubMed
  30. Psychol Med. 1988 Nov;18(4):1007-19 - PubMed
  31. Sleep Med Rev. 2013 Apr;17(2):105-21 - PubMed
  32. Harv Rev Psychiatry. 2008;16(5):279-86 - PubMed
  33. Sleep Med. 2007 Aug;8(5):503-8 - PubMed
  34. J Sleep Res. 1999 Sep;8(3):185-8 - PubMed
  35. J Physiol. 1999 Apr 15;516 ( Pt 2):611-27 - PubMed
  36. Sleep. 1982;5(2):195-9 - PubMed
  37. Sleep Med Rev. 2002 Aug;6(4):267-86 - PubMed
  38. Sleep. 1992 Apr;15(2):173-84 - PubMed
  39. Neuroreport. 2001 Dec 21;12(18):A111-24 - PubMed
  40. J Am Geriatr Soc. 2001 Apr;49(4):360-6 - PubMed
  41. Nature. 2004 Jul 1;430(6995):78-81 - PubMed
  42. Neurosci Lett. 2008 Feb 27;432(3):228-31 - PubMed

Publication Types