Dynamic relationships between sleep spindles and delta waves during a NREM period

Sunao Uchida*, Yoshikata Atsumi, Takuya Kojima

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)


All-night sleep EEGs from 7 normal young male adults were analyzed by a waveform recognition method using FFT-IFFT band pass filters. The total durations of sleep spindles and sleep delta waves in each 20-s epoch were measured and plotted on an X-Y graph with lines connecting the points in time sequence (dynamic two-component plot). The relationship between these two measures within a single NREM period showed three dynamic phases and one stationary period. In the first phase, spindles increased while delta remained at a low level or increased slightly. In the second phase, delta increased greatly while spindles decreased. In the third phase, delta decreased while spindles remained at a low level. There was a stationary period between the second and third phases, when delta maintained a higher level and spindles maintained a lower level. These dynamic descriptions reflect the underlying physiological mechanisms more directly than static sleep stages. They should also permit finer analyses of sleep in psychiatric and neurological disorders.

Original languageEnglish
Pages (from-to)351-355
Number of pages5
JournalBrain Research Bulletin
Issue number3
Publication statusPublished - 1994
Externally publishedYes


  • Computer analysis
  • Delta wave
  • Dynamic two-component plot
  • EEG
  • NREM sleep
  • Physiology
  • Sleep
  • Sleep phase
  • Sleep spindle
  • Waveform recognition method

ASJC Scopus subject areas

  • Neuroscience(all)


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