The effects of experimental sleep fragmentation on cognitive processing

Raffaele Ferri, Valeria Drago, Debora Aricò, Oliviero Bruni, Roger W. Remington, Katherine Stamatakis, Naresh M. Punjabi

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


Objective: The primary objective of this study was to characterize the association between cyclic alternating pattern (CAP) and neurocognitive performance in a group of normal subjects before and after two nights of experimentally-induced sleep fragmentation. Subjects and methods: Fifteen healthy subjects underwent one night of uninterrupted and two sequential nights of experimental sleep fragmentation achieved by auditory and mechanical stimuli. Eight subjects were re-examined using a similar paradigm with three nights of uninterrupted sleep. Sleep was polygraphically recorded and CAP analysis was performed for all recordings. A battery of neurocognitive tests was performed for spatial attention, inhibition of return, mental rotation, and Stroop color word test in the afternoon following the first and third night of sleep under fragmented and non-fragmented conditions. Results: With sleep fragmentation, the percentage of slow-wave sleep was dramatically reduced and there was a twofold increase in total CAP rate across all NREM sleep stages. Moreover, the number of all CAP A subtypes/hour of sleep (index) was significantly increased. Total CAP rate during the non-fragmented night correlated with reaction times. Similarly, the percentages of A1 and A3 subtypes were negatively and positively correlated with reaction times, respectively. Of the neurocognitive test battery, however, only values obtained from some subtests of the mental rotation test showed a significant improvement after sleep fragmentation. Conclusions: The results of this study suggest that CAP A1 subtypes are associated with higher cognitive functioning, whereas CAP A3 subtypes are associated with lower cognitive functioning in young healthy subjects. The lack of cognitive functioning impairment after sleep fragmentation may be due to persistence and even enhancement of transient slow-wave activity contained in CAP A1 subtypes which also caused a significant enhancement of the EEG power spectrum in the lower frequencies.

Original languageEnglish (US)
Pages (from-to)378-385
Number of pages8
JournalSleep Medicine
Issue number4
StatePublished - Apr 2010
Externally publishedYes


  • Arousals
  • Cyclic alternating pattern
  • Neurocognitive function
  • Sleep fragmentation
  • Sleep instability
  • Slow-wave sleep

ASJC Scopus subject areas

  • General Medicine


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