Quantification of Sleepiness: A New Approach

Authors

  • E. Hoddes,

    Corresponding author
    1. Department of Psychiatry, Stanford University School of Medicine
      Address requests for reprints to: Eric Hoddes, Department of Psychiatry, Stanford University School of Medicine, Stanford, Calif. 94305.
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    • 1

      Supported by National Institute of Mental Health Grant MH19071.

  • V. Zarcone,

    1. Department of Psychiatry, Stanford University School of Medicine
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    • 2

      Supported by National Institute of Mental Health Grant MH19071 and by funds from the Veterans Administration Hospital, Palo Alto, Calif.

  • H. Smythe,

    1. Department of Psychiatry, Stanford University School of Medicine
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    • 1

      Supported by National Institute of Mental Health Grant MH19071.

  • R. Phillips,

    1. Department of Psychiatry, Stanford University School of Medicine
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    • 3

      Supported by research funds from the Veterans Administration.

  • W. C. Dement

    1. Department of Psychiatry, Stanford University School of Medicine
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    • 4

      Supported by National Institute of Mental Health Grant MH13860, Research Career Development Award 3 K3-MH 5804 from U.S. Public Health Service, Grant NGR 05-020-168 from the National Aeronautics and Space Administration.


Address requests for reprints to: Eric Hoddes, Department of Psychiatry, Stanford University School of Medicine, Stanford, Calif. 94305.

ABSTRACT

The Stanford Sleepiness Scale (SSS) is a self-rating scale which is used to quantify progressive steps in sleepiness. The present study investigated whether the SSS cross-validates with performance on mental tasks and whether the SSS demonstrates changes in sleepiness with sleep loss. Five college student Ss were given a brief test of memory and the Wilkinson Addition Test in 2 test sessions and The Wilkinson Vigilance Test in 2 other sessions spaced throughout a 16-hr day for 6 days. Ss made SSS ratings every 15 min during their waking activities. On night 4, Ss underwent all night sleep deprivation. On all other nights, Ss were allowed only 8 hrs in bed. Mean SSS ratings correlated r= .68 with performance on the Wilkinson Tests. Discrete SSS ratings correlated r= .47 with performance on the memory test. Moreover, mean baseline SSS ratings were found to be significantly lower than corresponding ratings of the deprivation period.

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