This study is a new proposal concerned with a behavioral intervention, that of taking an afternoon nap, which might lessen some of the sleep and alertness disorders experienced by many older men and women. The major aim of this experiment is to determine whether for older people (70y+), a daily 90-minute early afternoon """"""""siesta nap"""""""" regimen, applied for 2 weeks in the home followed by 3 days in the laboratory, will help promote evening alertness and prevent Unwanted Early Evening Sleepiness (UEES) which may be manifest as evening napping and/or Advanced Sleep Phase Syndrome (ASPS) symptoms. A within-subject design will be employed with all subjects doing both conditions, half of the subjects doing the 'nap' condition first, half the 'no-nap' condition first. Eighteen days will intervene between the two conditions. The applicants will study both healthy controls and sleep disorders patients who complain of UEES symptoms, expecting the intervention to be most beneficial for the patient group. Home-based measures will include subjective ratings of alertness, sleep (and nap) diaries, the Social Rhythm Metric (SRM), and Actillume measures of wrist activity and light level. Laboratory measures will additionally include rectal temperature, polysomnographic measures of naps and sleeps, and single MSLT and waking EEG evening measures of sleepiness. For both patient (10m, 10f) and control (10m, 10f) groups, the applicants will test the hypothesis that the siesta nap regimen, imposed for 14 days at home and for three days in the laboratory, will have the effect of: 1) delaying the self selected bedtime and/or eliminating evening naps, 2) improving evening performance at manual dexterity, serial response, response inhibition and monotonous visual vigilance tasks, 3) increasing evening subjective alertness (self- rated) and decreasing objective evening sleepiness (MSLT trial, waking EEG analysis), 4) changing the pattern of light exposure and 5) increasing the level of lifestyle regularity. The intervention is derived from Borbely's original """"""""Process S/Process C"""""""" model of the human circadian system, and laboratory sleep and circadian measures will be used additionally to investigate the mechanisms of the model, and to evaluate any consequences of the siesta naps on circadian rhythm timing and nocturnal sleep. Results from the experiment will reveal the potential benefits (and costs) to older people of a lifestyle that incorporates an early afternoon nap, and determine how these vary between healthy seniors and those complaining of symptoms related to unwanted early evening sleepiness.

National Institute of Health (NIH)
National Institute on Aging (NIA)
Research Project (R01)
Project #
Application #
Study Section
Mental Disorders of Aging Review Committee (MDA)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Pittsburgh
Schools of Medicine
United States
Zip Code
Monk, Timothy H (2005) The post-lunch dip in performance. Clin Sports Med 24:e15-23, xi-xii
Monk, Timothy H; Buysse, Daniel J; Potts, Jaime M et al. (2004) Morningness-eveningness and lifestyle regularity. Chronobiol Int 21:435-43
Monk, Timothy H; Reynolds 3rd, Charles F; Buysse, Daniel J et al. (2003) The relationship between lifestyle regularity and subjective sleep quality. Chronobiol Int 20:97-107
Monk, Timothy H; Welsh, David K (2003) The role of chronobiology in sleep disorders medicine. Sleep Med Rev 7:455-73
Monk, Timothy H; Buysse, Daniel J; Kennedy, Kathy S et al. (2003) Measuring sleep habits without using a diary: the sleep timing questionnaire. Sleep 26:208-12
Dew, Mary Amanda; Hoch, Carolyn C; Buysse, Daniel J et al. (2003) Healthy older adults' sleep predicts all-cause mortality at 4 to 19 years of follow-up. Psychosom Med 65:63-73
Monk, Timothy H; Frank, Ellen; Potts, Jaime M et al. (2002) A simple way to measure daily lifestyle regularity. J Sleep Res 11:183-90
Moul, Douglas E; Ombao, Hernando; Monk, Timothy H et al. (2002) Masking effects of posture and sleep onset on core body temperature have distinct circadian rhythms: results from a 90-min/day protocol. J Biol Rhythms 17:447-62
Monk, T H; Kennedy, K S; Rose, L R et al. (2001) Decreased human circadian pacemaker influence after 100 days in space: a case study. Psychosom Med 63:881-5
Monk, T H; Buysse, D J; Welsh, D K et al. (2001) A sleep diary and questionnaire study of naturally short sleepers. J Sleep Res 10:173-9

Showing the most recent 10 out of 18 publications