Division of Sleep Medicine @ Harvard Medical School
Faculty Profile
Jeanne F. Duffy, MBA, PhD
Assistant Professor of Medicine, Harvard Medical School
Associate Neuroscientist, Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital
Address
221 Longwood Avenue, BLI - Rm 438Boston, MA 02115
USA
Inter-office Mail Address
BWH Division of Sleep Medicine, BLI438Phone 617-732-7995
Fax 617-732-4015
Email jduffy@hms.harvard.edu
Society Memberships
Sleep Research SocietySociety for Neuroscience
Society for Research on Biological Rhythms
European Sleep Research Society
Research Unit(s)
Circadian Group, Division of Sleep Medicine, Brigham and Women's Hospital
Chronobiology Core, Division of Sleep Medicine, Brigham and Women's Hospital
Chronobiology Core, Division of Sleep Medicine, Brigham and Women's Hospital
Research Interests
My research interests include both basic and applied aspects of circadian physiology. My recent work has focused on understanding individual differences in human circadian rhythms, including how aging affects circadian rhythms and how diurnal preference (morningness-eveningness) is related to individual differences in human circadian rhythms.
My research on aging examines several aspects of human circadian rhythmicity, including whether there are age-related changes in the response of the human circadian system to light; whether there are age-related differences in light exposure patterns in humans; how manipulation of the relationship between sleep and circadian rhythmicity affects sleep quality and quantity; whether pre-sleep melatonin administration can improve sleep quality in older people; and whether healthy older adults are more resistant to sleep deprivation than young adults.
The other major research area I am currently pursuing is studying individuals who are extreme early birds or night owls. My research on diurnal type is focused on how an individual's circadian period influences the timing of their daily biological rhythms, how the phase relationship between sleep and the timing of daily rhythms is related to an individual's morningness-eveningness preference, the magnitude of the circadian influence on sleep and performance in extreme diurnal types, and what role "clock genes" play in determining circadian period and diurnal type.
In addition to those areas described above, my research interests include understanding the underlying factors contributing to circadian rhythm sleep disorders such as shift-work dyssomnia, advanced and delayed sleep phase syndromes and jet lag, and pursuing novel treatments for those disorders.
My research on aging examines several aspects of human circadian rhythmicity, including whether there are age-related changes in the response of the human circadian system to light; whether there are age-related differences in light exposure patterns in humans; how manipulation of the relationship between sleep and circadian rhythmicity affects sleep quality and quantity; whether pre-sleep melatonin administration can improve sleep quality in older people; and whether healthy older adults are more resistant to sleep deprivation than young adults.
The other major research area I am currently pursuing is studying individuals who are extreme early birds or night owls. My research on diurnal type is focused on how an individual's circadian period influences the timing of their daily biological rhythms, how the phase relationship between sleep and the timing of daily rhythms is related to an individual's morningness-eveningness preference, the magnitude of the circadian influence on sleep and performance in extreme diurnal types, and what role "clock genes" play in determining circadian period and diurnal type.
In addition to those areas described above, my research interests include understanding the underlying factors contributing to circadian rhythm sleep disorders such as shift-work dyssomnia, advanced and delayed sleep phase syndromes and jet lag, and pursuing novel treatments for those disorders.
Trainees
Undergraduates:
Jason Rodriguez, 2001
Marie Cadet, 2001
Alison M. Laffan, 2001-2002
Alex S.W. Lowe, 2003-2004
Hannah Willson, 2005-2007
John Hares, 2005-2006
Stephanie Romiszewsk, 2005-2007
Fanuel Muindi, 2007-present
Rachel Zhang, 2007-present
Medical Students:
Rashad J. Harris, 2005
Van T. Nguyen, 2005
Post-doctoral Fellows:
Nayantara Santhi, PhD, 2002-2005
Anne-Marie Chang, PhD, 2003-present
Karine D. Scheuermaier, MD, 2006-present
Sean W. Cain, PhD, 2006-present
Mirjam Y. Münch, PhD, 2006-present
Jason Rodriguez, 2001
Marie Cadet, 2001
Alison M. Laffan, 2001-2002
Alex S.W. Lowe, 2003-2004
Hannah Willson, 2005-2007
John Hares, 2005-2006
Stephanie Romiszewsk, 2005-2007
Fanuel Muindi, 2007-present
Rachel Zhang, 2007-present
Medical Students:
Rashad J. Harris, 2005
Van T. Nguyen, 2005
Post-doctoral Fellows:
Nayantara Santhi, PhD, 2002-2005
Anne-Marie Chang, PhD, 2003-present
Karine D. Scheuermaier, MD, 2006-present
Sean W. Cain, PhD, 2006-present
Mirjam Y. Münch, PhD, 2006-present
Research Funding
NIA P01AG009975
"Alertness and cognitive performance in sleep-restricted older people"
Role: PI
NIH/NIA R01AG06072
"Disrupted sleep in the elderly: circadian etiology"
The goal of this project is to test a light treatment regimen that uses a blue-enriched fluorescent light source to better align the timing of the sleep-wake cycle and the phase of the circadian timing system in older individuals with complaints of sleep maintenance insomnia and/or early morning awakening.
Role: PI
NIH/NCCAM R21AT002571
"Effect of vitamin B12 on the human circadian pacemaker"
The goal of this project is to test vitamin B12's effects on circadian period in a placebo-controlled study in healthy subjects, using the forced desynchrony protocol to measure circadian period precisely.
Role: PI
NIH/NHLBI R01HL080978
"Circadian & genetic evaluation of extreme sleep timing"
The goal of this project is to conduct a phenotypic and genetic evaluation of extreme diurnal types in order to determine the underlying chronobiologic and genetic basis of human diurnal preference. We will measure sleep timing, circadian phase, circadian period, and the circadian rhythm of sleep propensity, as well as assess known polymorphisms in circadian genes and explore novel polymorphisms, thereby linking specific genes with observable behavior.
Role: PI
NIH/NIA Program Project P01AG009975
"Sleep aging and circadian rhythm disorders"
PI: Charles A. Czeisler, PhD, MD, FRCP.
The goals of the Program Project are to understand how older people respond to chronic sleep restriction. The program will investigate changes in sleep, waking neurobehavioral performance, and metabolism, at the behavioral and electrophysical levels as well as at the neuro-anatomical level.
Role: Co-Investigator, Project 1 Circadian and Homeostatic Sleep Regulation in Older People; Project Leader, Project 2 Alertness and Cognitive Performance in Sleep-Restricted Older People.
NIH/NIMH R01MH045130
"Treatment of circadian sleep disorders with bright light"
PI: Charles A. Czeisler, PhD, MD, FRCP.
The goal of this project is to test the human circadian response to short-wavelength monochromatic light, including the phase-dependent resetting response, the melatonin-suppressing response, and the acute alerting response.
Role: Co-Investigator.
NIH/NHLBI T32HL007901
"Training in sleep, circadian and respiratory neurobiology"
PI: Charles A. Czeisler, PhD., MD FRCP.
The goal of this institutional training program is to provide a structured, comprehensive program to train outstanding individuals for academic positions in the broad field of sleep disorders medicine with specific expertise in basic science, patient-oriented or applied research.
Role: Faculty preceptor.
"Alertness and cognitive performance in sleep-restricted older people"
Role: PI
NIH/NIA R01AG06072
"Disrupted sleep in the elderly: circadian etiology"
The goal of this project is to test a light treatment regimen that uses a blue-enriched fluorescent light source to better align the timing of the sleep-wake cycle and the phase of the circadian timing system in older individuals with complaints of sleep maintenance insomnia and/or early morning awakening.
Role: PI
NIH/NCCAM R21AT002571
"Effect of vitamin B12 on the human circadian pacemaker"
The goal of this project is to test vitamin B12's effects on circadian period in a placebo-controlled study in healthy subjects, using the forced desynchrony protocol to measure circadian period precisely.
Role: PI
NIH/NHLBI R01HL080978
"Circadian & genetic evaluation of extreme sleep timing"
The goal of this project is to conduct a phenotypic and genetic evaluation of extreme diurnal types in order to determine the underlying chronobiologic and genetic basis of human diurnal preference. We will measure sleep timing, circadian phase, circadian period, and the circadian rhythm of sleep propensity, as well as assess known polymorphisms in circadian genes and explore novel polymorphisms, thereby linking specific genes with observable behavior.
Role: PI
NIH/NIA Program Project P01AG009975
"Sleep aging and circadian rhythm disorders"
PI: Charles A. Czeisler, PhD, MD, FRCP.
The goals of the Program Project are to understand how older people respond to chronic sleep restriction. The program will investigate changes in sleep, waking neurobehavioral performance, and metabolism, at the behavioral and electrophysical levels as well as at the neuro-anatomical level.
Role: Co-Investigator, Project 1 Circadian and Homeostatic Sleep Regulation in Older People; Project Leader, Project 2 Alertness and Cognitive Performance in Sleep-Restricted Older People.
NIH/NIMH R01MH045130
"Treatment of circadian sleep disorders with bright light"
PI: Charles A. Czeisler, PhD, MD, FRCP.
The goal of this project is to test the human circadian response to short-wavelength monochromatic light, including the phase-dependent resetting response, the melatonin-suppressing response, and the acute alerting response.
Role: Co-Investigator.
NIH/NHLBI T32HL007901
"Training in sleep, circadian and respiratory neurobiology"
PI: Charles A. Czeisler, PhD., MD FRCP.
The goal of this institutional training program is to provide a structured, comprehensive program to train outstanding individuals for academic positions in the broad field of sleep disorders medicine with specific expertise in basic science, patient-oriented or applied research.
Role: Faculty preceptor.
Teaching
HMS Program for Research and Investigation in Science and Math, Lecturer
HMS Explorations for Middle School Students Program, Laboratory Host
HMS Division of Sleep Medicine Institutional NRSA "Sleep, Aging and Circadian Rhythm Disorders", Preceptor
HMS Division on Aging Geriatric Psychiatry Summer Seminars, Lecturer
NSF Chautauqua Short Course for College Teachers, Faculty Member
HMS Explorations for Middle School Students Program, Laboratory Host
HMS Division of Sleep Medicine Institutional NRSA "Sleep, Aging and Circadian Rhythm Disorders", Preceptor
HMS Division on Aging Geriatric Psychiatry Summer Seminars, Lecturer
NSF Chautauqua Short Course for College Teachers, Faculty Member
Selected Publications
Lee JH, Wang W, Silva EJ, Chang AM, Scheuermaier KD, Cain SW, Duffy JF. Neurobehavioral performance in young adults living on a 28-h day for 6 weeks.
Sleep. 2009 Jul 1;32(7):905-13. [PMID: 19639753]
O’Donnell D, Silva EJ, Münch M, Ronda JM, Wang W, Duffy JF. Comparison of subjective and objective assessments of sleep in healthy older subjects without sleep complaints.
J Sleep Res. 2009 Jun;18(2):254-63. [PMID: 19645969]
Duffy JF, Willson HJ, Wang W, Czeisler CA. Healthy older adults better tolerate sleep deprivation than young adults.
J Am Geriatr Soc. 2009 Jul;57(7):1245-51. Epub 2009 Apr 30. [PMID: 19460089]
Silva EJ, Duffy JF. Sleep inertia varies with circadian phase and sleep stage in older adults.
Behav Neurosci. 2008 Aug;122(4):928-35. [PMID: 18729646]
Pavlova MK, Duffy JF, Shea SA. Polysomnographic respiratory abnormalities in asymptomatic individuals.
Sleep. 2008 Feb 1;31(2):241-8. [PMID: 18274272]
Kuhlman SJ, Mackey SR, Duffy JF. Biological Rhythms Workshop I: Introduction to Chronobiology.
Cold Spring Harb Symp Quant Biol. 2007; 72:1-6. [PMID: 18419258]
Munch MY, Cain SW, Duffy JF. Biological Rhythms Workshop IC: Sleep and rhythms.
Cold Spring Harb Symp Quant Biol. 2007; 72:35-46. [PMID: 18419261]
Zeitzer JM, Duffy JF, Lockley SW, Dijk DJ, Czeisler CA. Plasma melatonin rhythms in young and older humans during sleep, sleep deprivation, and wake.
Sleep. 2007; 30:1437-1443. [PMID: 18041478]
Santhi N, Horowitz TS, Duffy JF, Czeisler CA. Acute sleep deprivation and circadian misalignment associated with transition onto the first night of work impairs visual selective attention.
PLoS ONE. 2007; 2:e1233. [PMID: 18043740]
Cain SW, Rimmer DW, Duffy JF, Czeisler CA. Exercise distributed across day and night does not alter circadian period in humans.
J Biol Rhythms 2007; 22:534-541. [PMID: 18057328]
Duffy JF, Zeitzer JM, Czeisler CA. Decreased sensitivity to phase-delaying effects of moderate intensity light in older subjects.
Neurobiol Aging. 2007 May;28(5):799-807. Epub 2006 Apr 18. [PMID: 16621166]
Duffy JF. Increased sleep disruption, reduced sleepiness in older subjects? Commentary on Circadian patterns of sleep, sleepiness, and performance in older and younger adults.
Sleep. 2005 Nov 1;28(11):1358-9. [PMID: 16335324]
Santhi N, Duffy JF, Czeisler CA. Scheduling of sleep/darkness affects the circadian phase of night shift workers.
Neurosci Lett. 2005 Aug 26;384(3):316-20. [PMID: 15919151]
Wright Jr. KP, Gronfier C, Duffy JF, Czeisler CA. Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans.
J Biol Rhythms. 2005; 20:168-177. [PMID: 15834113]
Zeitzer JM, Khalsa SBS, Boivin DB, Duffy JF, Shanahan TL, Kronauer RE, Czeisler CA. Temporal dynamics of late night photic stimulation of the human circadian timing system.
Am J Physiol. 2005; 289:R839-R844. [PMID: 15890792]
Duffy JF, Wright KP Jr. Entrainment of human circadian rhythms by light.
J Biol Rhythms. 2005 Aug;20(4):326-38. [PMID: 16077152]
Klerman EB, Davis JB, Duffy JF, Dijk DJ, Kronauer RE. Older people awaken more frequently but fall back asleep at the same rate as younger people.
Sleep. 2004; 27:793-798. [PMID: 15283016]
Duffy JF, Dijk DJ. Getting through to circadian oscillators: Why use constant routines?
J Biol Rhythms. 2002 Feb;17(1):4-13. [PMID: 11837947]
Khalsa SBS, Conroy DA, Duffy JF, Czeisler CA, Dijk DJ. Sleep and circadian-dependent modulation of REM density.
J Sleep Res. 2002; 11:53-59. [PMID: 11869427]
Klerman EB, Gershengorn HB, Duffy JF, Kronauer RE. Comparisons of the variability of three markers of the human circadian pacemaker.
J Biol Rhythms. 2002; 17:181-193. [PMID: 12002165]
Duffy JF, Zeitzer JM, Rimmer DW, Klerman EB, Dijk DJ, Czeisler CA. Peak of circadian melatonin rhythm occurs later within the sleep of older subjects.
Am J Physiol Endocrinol Metab. 2002 Feb;282(2):E297-303. [PMID: 11788360]
Duffy JF, Czeisler CA. Age-related change in the relationship between circadian period, circadian phase, and diurnal preference in humans.
Neurosci Lett. 2002 Feb 1;318(3):117-20. [PMID: 11803113]
Duffy JF, Rimmer DW, Czeisler CA. Association of intrinsic circadian period with morningness-eveningness, usual wake time, and circadian phase.
Behav Neurosci. 2001 Aug;115(4):895-9. [PMID: 11508728]
Dijk DJ, Duffy JF, Czeisler CA. Age-related increase in awakenings: impaired consolidation of nonREM sleep at all circadian phases.
Sleep. 2001 Aug 1;24(5):565-77. [PMID: 11480654]
Klerman EB, Zeitzer JM, Duffy JF, Khalsa SBS, Czeisler CA. Absence of an increase in the duration of the circadian melatonin secretory episode in totally blind human subjects.
J Clin Endocrinol Metab 2001; 86:3166-3170. [PMID: 11443183]
Klerman EB, Duffy JF, Dijk DJ, Czeisler CA. Circadian phase resetting in older people by ocular bright light exposure.
J Investig Med. 2001 Jan;49(1):30-40. [PMID: 11217145]
Rimmer DW, Boivin DB, Shanahan TL, Kronauer RE, Duffy JF, Czeisler CA. Dynamic resetting of the human circadian pacemaker by intermittent bright light.
Am J Physiol. 2000; 279:R1574-R1579. [PMID: 11049838]
Dijk DJ, Duffy JF, Czeisler CA. Contribution of circadian physiology and sleep homeostasis to age-related changes in human sleep.
Chronobiol Int. 2000; 17:285-311. [PMID: 10841208]
Khalsa SBS, Jewett ME, Duffy JF, Czeisler CA. The timing of the human circadian clock is accurately represented by the core body temperature rhythm following phase shifts to a three-cycle light stimulus near the critical zone.
J Biol Rhythms. 2000; 15:524-530. [PMID: 11106069]
Duffy JF, Viswanathan N, Davis FC. Free-running circadian period does not shorten with age in female Syrian hamsters.
Neurosci Lett. 1999; 271:77-80. [PMID: 10477106]
Dijk DJ, Duffy JF. Circadian regulation of human sleep and age-related changes in its timing, consolidation and EEG characteristics.
Ann Med. 1999; 31:130-140. [PMID: 10344586]
Zeitzer JM, Daniels JE, Duffy JF, Klerman EB, Shanahan TL, Dijk DJ, Czeisler CA. Do plasma melatonin concentrations decline with age?
Am J Med. 1999 Nov;107(5):432-6. [PMID: 10569297]
Dijk DJ, Duffy JF, Riel E, Shanahan TL, Czeisler CA. Ageing and the circadian and homeostatic regulation of human sleep during forced desynchrony of rest, melatonin and temperature rhythms.
J Physiol (Lond). 1999; 516:611-627. [PMID: 10087357]
Shanahan TL, Kronauer RE, Duffy JF, Williams GH, Czeisler CA. Melatonin rhythm observed throughout a three-cycle bright light stimulus designed to reset the human circadian pacemaker.
J Biol Rhythms. 1999; 14:237-253. [PMID: 10452336]
Czeisler CA, Duffy JF, Shanahan TL, Brown EN, Mitchell JF, Rimmer DW, Ronda JM, Silva EJ, Allan JS, Emens JS, Dijk DJ, Kronauer RE. Stability, precision, and near-24-hour period of the human circadian pacemaker.
Science. 1999 Jun 25;284(5423):2177-81. [PMID: 10381883]
Duffy JF, Dijk DJ, Hall EF, Czeisler CA. Relationship of endogenous circadian melatonin and temperature rhythms to self-reported preference for morning or evening activity in young and older people.
J Investig Med. 1999 Mar;47(3):141-50. [PMID: 10198570]
Duffy JF, Dijk DJ, Klerman EB, Czeisler CA. Later endogenous circadian temperature nadir relative to an earlier wake time in older people.
Am J Physiol. 1998 Nov;275(5 Pt 2):R1478-87. [PMID: 9791064]
Boivin DB, Czeisler CA, Dijk DJ, Duffy JF, Folkard S, Minors D, Totterdell P, Waterhouse J. Complex interaction of the sleep-wake cycle and circadian phase modulates mood in healthy subjects.
Arch Gen Psychiatry. 1997;54:145-152. [PMID: 9040282]
Jewett ME, Rimmer DW, Duffy JF, Klerman EB, Kronauer RE, Czeisler CA. Human circadian pacemaker is sensitive to light throughout subjective day without evidence of transients.
Am J Physiol. 1997;273:R1800-R1809. [PMID: 9374826]
Dijk DJ, Shanahan TL, Duffy JF, Ronda JM, Czeisler CA. Variation of electroencephalographic activity during nonREM and REM sleep with phase of circadian melatonin rhythm in humans.
J Physiol (Lond). 1997;505:851-858. [PMID: 9457658]
Duffy JF, Kronauer RE, Czeisler CA. Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure.
J Physiol (Lond). 1996 Aug 15;495 ( Pt 1):289-97. [PMID: 8866371]
Boivin DB, Duffy JF, Kronauer RE, Czeisler CA. Dose-response relationships for resetting of human circadian clock by light.
Nature. 1996 Feb 8;379(6565):540-2. [PMID: 8596632]
Boivin DB, Duffy JF, Kronauer RE, Czeisler CA. Sensitivity of the human circadian pacemaker to moderately bright light.
J Biol Rhythms. 1994;9:315-331. [PMID: 7772798]
Waldstreicher J, Duffy JF, Brown EN, Rogacz S, Allan JS, Czeisler CA. Gender differences in the temporal organization of prolactin (PRL) secretion: Evidence for a sleep-independent circadian rhythm of circulating PRL levels.
J Clin Endocrinol Metab. 1996;81:1483-1487. [PMID: 8636355]
Czeisler CA, Dumont M, Duffy JF, Steinberg JD, Richardson GS, Brown EN, Sánchez R, Ríos CD, Ronda JM. Association of sleep-wake habits in older people with changes in output of circadian pacemaker.
Lancet. 1992;340:933-936. [PMID: 1357348]
Dijk DJ, Duffy JF, Czeisler CA. Circadian and sleep-wake dependent aspects of subjective alertness and cognitive performance.
J Sleep Res. 1992;2:112-117. [PMID: 10607036]
Johnson MP, Duffy JF, Dijk DJ, Ronda JM, Dyal CM, Czeisler CA. Short-term memory, alertness and performance: a reappraisal of their relationship to body temperature.
J Sleep Res. 1992 Mar;1(1):24-9. [PMID: 10607021]
Czeisler CA, Chiasera AJ, Duffy JF. Research on sleep, circadian rhythms and aging: Applications to manned space flight.
Exp Gerontol. 1991;26:217 232. [PMID: 1915692]
Czeisler CA, Johnson MP, Duffy JF, Brown EN, Ronda JM, Kronauer RE. Exposure to bright light and darkness to treat physiologic maladaptation to night work.
N Engl J Med. 1990 May 3;322(18):1253-9. [PMID: 2325721]
Czeisler CA, Kronauer RE, Allan JS, Duffy JF, Jewett ME, Brown EN, Ronda JM. Bright light induction of strong (Type 0) resetting of the human circadian pacemaker.
Science 1989;244:1328 1331. [PMID: 2734611]
Book Chapters
Duffy JF, Czeisler CA. Effect of light on human circadian physiology.
Sleep Med Clin. 2009; in press.
Duffy JF. Shift work and aging: Roles of sleep and circadian rhythms.
Clinics in OEM. 2003; 3:311-332.
Sleep. 2009 Jul 1;32(7):905-13. [PMID: 19639753]
O’Donnell D, Silva EJ, Münch M, Ronda JM, Wang W, Duffy JF. Comparison of subjective and objective assessments of sleep in healthy older subjects without sleep complaints.
J Sleep Res. 2009 Jun;18(2):254-63. [PMID: 19645969]
Duffy JF, Willson HJ, Wang W, Czeisler CA. Healthy older adults better tolerate sleep deprivation than young adults.
J Am Geriatr Soc. 2009 Jul;57(7):1245-51. Epub 2009 Apr 30. [PMID: 19460089]
Silva EJ, Duffy JF. Sleep inertia varies with circadian phase and sleep stage in older adults.
Behav Neurosci. 2008 Aug;122(4):928-35. [PMID: 18729646]
Pavlova MK, Duffy JF, Shea SA. Polysomnographic respiratory abnormalities in asymptomatic individuals.
Sleep. 2008 Feb 1;31(2):241-8. [PMID: 18274272]
Kuhlman SJ, Mackey SR, Duffy JF. Biological Rhythms Workshop I: Introduction to Chronobiology.
Cold Spring Harb Symp Quant Biol. 2007; 72:1-6. [PMID: 18419258]
Munch MY, Cain SW, Duffy JF. Biological Rhythms Workshop IC: Sleep and rhythms.
Cold Spring Harb Symp Quant Biol. 2007; 72:35-46. [PMID: 18419261]
Zeitzer JM, Duffy JF, Lockley SW, Dijk DJ, Czeisler CA. Plasma melatonin rhythms in young and older humans during sleep, sleep deprivation, and wake.
Sleep. 2007; 30:1437-1443. [PMID: 18041478]
Santhi N, Horowitz TS, Duffy JF, Czeisler CA. Acute sleep deprivation and circadian misalignment associated with transition onto the first night of work impairs visual selective attention.
PLoS ONE. 2007; 2:e1233. [PMID: 18043740]
Cain SW, Rimmer DW, Duffy JF, Czeisler CA. Exercise distributed across day and night does not alter circadian period in humans.
J Biol Rhythms 2007; 22:534-541. [PMID: 18057328]
Duffy JF, Zeitzer JM, Czeisler CA. Decreased sensitivity to phase-delaying effects of moderate intensity light in older subjects.
Neurobiol Aging. 2007 May;28(5):799-807. Epub 2006 Apr 18. [PMID: 16621166]
Duffy JF. Increased sleep disruption, reduced sleepiness in older subjects? Commentary on Circadian patterns of sleep, sleepiness, and performance in older and younger adults.
Sleep. 2005 Nov 1;28(11):1358-9. [PMID: 16335324]
Santhi N, Duffy JF, Czeisler CA. Scheduling of sleep/darkness affects the circadian phase of night shift workers.
Neurosci Lett. 2005 Aug 26;384(3):316-20. [PMID: 15919151]
Wright Jr. KP, Gronfier C, Duffy JF, Czeisler CA. Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans.
J Biol Rhythms. 2005; 20:168-177. [PMID: 15834113]
Zeitzer JM, Khalsa SBS, Boivin DB, Duffy JF, Shanahan TL, Kronauer RE, Czeisler CA. Temporal dynamics of late night photic stimulation of the human circadian timing system.
Am J Physiol. 2005; 289:R839-R844. [PMID: 15890792]
Duffy JF, Wright KP Jr. Entrainment of human circadian rhythms by light.
J Biol Rhythms. 2005 Aug;20(4):326-38. [PMID: 16077152]
Klerman EB, Davis JB, Duffy JF, Dijk DJ, Kronauer RE. Older people awaken more frequently but fall back asleep at the same rate as younger people.
Sleep. 2004; 27:793-798. [PMID: 15283016]
Duffy JF, Dijk DJ. Getting through to circadian oscillators: Why use constant routines?
J Biol Rhythms. 2002 Feb;17(1):4-13. [PMID: 11837947]
Khalsa SBS, Conroy DA, Duffy JF, Czeisler CA, Dijk DJ. Sleep and circadian-dependent modulation of REM density.
J Sleep Res. 2002; 11:53-59. [PMID: 11869427]
Klerman EB, Gershengorn HB, Duffy JF, Kronauer RE. Comparisons of the variability of three markers of the human circadian pacemaker.
J Biol Rhythms. 2002; 17:181-193. [PMID: 12002165]
Duffy JF, Zeitzer JM, Rimmer DW, Klerman EB, Dijk DJ, Czeisler CA. Peak of circadian melatonin rhythm occurs later within the sleep of older subjects.
Am J Physiol Endocrinol Metab. 2002 Feb;282(2):E297-303. [PMID: 11788360]
Duffy JF, Czeisler CA. Age-related change in the relationship between circadian period, circadian phase, and diurnal preference in humans.
Neurosci Lett. 2002 Feb 1;318(3):117-20. [PMID: 11803113]
Duffy JF, Rimmer DW, Czeisler CA. Association of intrinsic circadian period with morningness-eveningness, usual wake time, and circadian phase.
Behav Neurosci. 2001 Aug;115(4):895-9. [PMID: 11508728]
Dijk DJ, Duffy JF, Czeisler CA. Age-related increase in awakenings: impaired consolidation of nonREM sleep at all circadian phases.
Sleep. 2001 Aug 1;24(5):565-77. [PMID: 11480654]
Klerman EB, Zeitzer JM, Duffy JF, Khalsa SBS, Czeisler CA. Absence of an increase in the duration of the circadian melatonin secretory episode in totally blind human subjects.
J Clin Endocrinol Metab 2001; 86:3166-3170. [PMID: 11443183]
Klerman EB, Duffy JF, Dijk DJ, Czeisler CA. Circadian phase resetting in older people by ocular bright light exposure.
J Investig Med. 2001 Jan;49(1):30-40. [PMID: 11217145]
Rimmer DW, Boivin DB, Shanahan TL, Kronauer RE, Duffy JF, Czeisler CA. Dynamic resetting of the human circadian pacemaker by intermittent bright light.
Am J Physiol. 2000; 279:R1574-R1579. [PMID: 11049838]
Dijk DJ, Duffy JF, Czeisler CA. Contribution of circadian physiology and sleep homeostasis to age-related changes in human sleep.
Chronobiol Int. 2000; 17:285-311. [PMID: 10841208]
Khalsa SBS, Jewett ME, Duffy JF, Czeisler CA. The timing of the human circadian clock is accurately represented by the core body temperature rhythm following phase shifts to a three-cycle light stimulus near the critical zone.
J Biol Rhythms. 2000; 15:524-530. [PMID: 11106069]
Duffy JF, Viswanathan N, Davis FC. Free-running circadian period does not shorten with age in female Syrian hamsters.
Neurosci Lett. 1999; 271:77-80. [PMID: 10477106]
Dijk DJ, Duffy JF. Circadian regulation of human sleep and age-related changes in its timing, consolidation and EEG characteristics.
Ann Med. 1999; 31:130-140. [PMID: 10344586]
Zeitzer JM, Daniels JE, Duffy JF, Klerman EB, Shanahan TL, Dijk DJ, Czeisler CA. Do plasma melatonin concentrations decline with age?
Am J Med. 1999 Nov;107(5):432-6. [PMID: 10569297]
Dijk DJ, Duffy JF, Riel E, Shanahan TL, Czeisler CA. Ageing and the circadian and homeostatic regulation of human sleep during forced desynchrony of rest, melatonin and temperature rhythms.
J Physiol (Lond). 1999; 516:611-627. [PMID: 10087357]
Shanahan TL, Kronauer RE, Duffy JF, Williams GH, Czeisler CA. Melatonin rhythm observed throughout a three-cycle bright light stimulus designed to reset the human circadian pacemaker.
J Biol Rhythms. 1999; 14:237-253. [PMID: 10452336]
Czeisler CA, Duffy JF, Shanahan TL, Brown EN, Mitchell JF, Rimmer DW, Ronda JM, Silva EJ, Allan JS, Emens JS, Dijk DJ, Kronauer RE. Stability, precision, and near-24-hour period of the human circadian pacemaker.
Science. 1999 Jun 25;284(5423):2177-81. [PMID: 10381883]
Duffy JF, Dijk DJ, Hall EF, Czeisler CA. Relationship of endogenous circadian melatonin and temperature rhythms to self-reported preference for morning or evening activity in young and older people.
J Investig Med. 1999 Mar;47(3):141-50. [PMID: 10198570]
Duffy JF, Dijk DJ, Klerman EB, Czeisler CA. Later endogenous circadian temperature nadir relative to an earlier wake time in older people.
Am J Physiol. 1998 Nov;275(5 Pt 2):R1478-87. [PMID: 9791064]
Boivin DB, Czeisler CA, Dijk DJ, Duffy JF, Folkard S, Minors D, Totterdell P, Waterhouse J. Complex interaction of the sleep-wake cycle and circadian phase modulates mood in healthy subjects.
Arch Gen Psychiatry. 1997;54:145-152. [PMID: 9040282]
Jewett ME, Rimmer DW, Duffy JF, Klerman EB, Kronauer RE, Czeisler CA. Human circadian pacemaker is sensitive to light throughout subjective day without evidence of transients.
Am J Physiol. 1997;273:R1800-R1809. [PMID: 9374826]
Dijk DJ, Shanahan TL, Duffy JF, Ronda JM, Czeisler CA. Variation of electroencephalographic activity during nonREM and REM sleep with phase of circadian melatonin rhythm in humans.
J Physiol (Lond). 1997;505:851-858. [PMID: 9457658]
Duffy JF, Kronauer RE, Czeisler CA. Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure.
J Physiol (Lond). 1996 Aug 15;495 ( Pt 1):289-97. [PMID: 8866371]
Boivin DB, Duffy JF, Kronauer RE, Czeisler CA. Dose-response relationships for resetting of human circadian clock by light.
Nature. 1996 Feb 8;379(6565):540-2. [PMID: 8596632]
Boivin DB, Duffy JF, Kronauer RE, Czeisler CA. Sensitivity of the human circadian pacemaker to moderately bright light.
J Biol Rhythms. 1994;9:315-331. [PMID: 7772798]
Waldstreicher J, Duffy JF, Brown EN, Rogacz S, Allan JS, Czeisler CA. Gender differences in the temporal organization of prolactin (PRL) secretion: Evidence for a sleep-independent circadian rhythm of circulating PRL levels.
J Clin Endocrinol Metab. 1996;81:1483-1487. [PMID: 8636355]
Czeisler CA, Dumont M, Duffy JF, Steinberg JD, Richardson GS, Brown EN, Sánchez R, Ríos CD, Ronda JM. Association of sleep-wake habits in older people with changes in output of circadian pacemaker.
Lancet. 1992;340:933-936. [PMID: 1357348]
Dijk DJ, Duffy JF, Czeisler CA. Circadian and sleep-wake dependent aspects of subjective alertness and cognitive performance.
J Sleep Res. 1992;2:112-117. [PMID: 10607036]
Johnson MP, Duffy JF, Dijk DJ, Ronda JM, Dyal CM, Czeisler CA. Short-term memory, alertness and performance: a reappraisal of their relationship to body temperature.
J Sleep Res. 1992 Mar;1(1):24-9. [PMID: 10607021]
Czeisler CA, Chiasera AJ, Duffy JF. Research on sleep, circadian rhythms and aging: Applications to manned space flight.
Exp Gerontol. 1991;26:217 232. [PMID: 1915692]
Czeisler CA, Johnson MP, Duffy JF, Brown EN, Ronda JM, Kronauer RE. Exposure to bright light and darkness to treat physiologic maladaptation to night work.
N Engl J Med. 1990 May 3;322(18):1253-9. [PMID: 2325721]
Czeisler CA, Kronauer RE, Allan JS, Duffy JF, Jewett ME, Brown EN, Ronda JM. Bright light induction of strong (Type 0) resetting of the human circadian pacemaker.
Science 1989;244:1328 1331. [PMID: 2734611]
Book Chapters
Duffy JF, Czeisler CA. Effect of light on human circadian physiology.
Sleep Med Clin. 2009; in press.
Duffy JF. Shift work and aging: Roles of sleep and circadian rhythms.
Clinics in OEM. 2003; 3:311-332.
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