Profil

Hammad Grégory

GIGA Neurosciences - Sleep and chronobiology

Département de Psychologie > Neuropsychologie de l'adulte

See author's contact details
ORCID
0000-0003-1083-3869
Main Referenced Co-authors
Schmidt, Christina  (52)
Muto, Vincenzo  (40)
Deantoni, Michele  (33)
Reyt, Mathilde  (32)
Baillet, Marion  (30)
Main Referenced Keywords
ageing (7); cognition (6); napping (4); Actigraphy (3); Neurology (clinical) (3);
Main Referenced Unit & Research Centers
GIGA CRC (Cyclotron Research Center) In vivo Imaging-Aging & Memory - ULiège (14)
GIGA-SLEEP - GIGA CRC In vivo Imaging-Sleep and chronobiology - ULiège (3)
GIGA CRC In vivo Imaging-Cognitive Neurosciences - ULiège (1)
Main Referenced Disciplines
Neurosciences & behavior (46)
Theoretical & cognitive psychology (6)
Neurology (4)
Life sciences: Multidisciplinary, general & others (2)
Electrical & electronics engineering (1)

Publications (total 59)

The most downloaded
1857 downloads
Hammad, G., Reyt, M., Beliy, N., Baillet, M., Deantoni, M., Lesoinne, A., Muto, V., & Schmidt, C. (2020). pyActigraphy: open-source python package for actigraphy data visualisation and analysis. ORBi-University of Liège. https://orbi.uliege.be/handle/2268/255113. doi:10.1101/2020.12.03.400226 https://hdl.handle.net/2268/255113

The most cited

47 citations (OpenAlex)

Hammad, G., Reyt, M., Beliy, N., Baillet, M., Deantoni, M., Lesoinne, A., Muto, V., & Schmidt, C. (19 October 2021). pyActigraphy: Open-source python package for actigraphy data visualization and analysis. PLoS Computational Biology, 17 (10), 1009514. doi:10.1371/journal.pcbi.1009514 https://hdl.handle.net/2268/267574

Articles in scientific journals with peer reviewing

Dourte, M., Hammad, G., Schmidt, C., & Peigneux, P. (22 March 2025). Uncorrelated Age-Related Changes in Visuo-Spatial Working Memory Binding and Thermoregulation. Clocks and Sleep, 7 (2), 17. doi:10.3390/clockssleep7020017
Peer reviewed

de Haan, S., Dourte, M., Deantoni, M., Reyt, M., Baillet, M., Berthomier, C., Muto, V., Hammad, G., Cajochen, C., Reichert, C. F., Maire, M., Schmidt, C., & Postnova, S. (02 January 2025). Impact of Varying Sleep Pressure on Daytime Sleep Propensity in Healthy Young and Older Adults. Clocks and Sleep, 7 (1). doi:10.3390/clockssleep7010002
Peer reviewed

Deantoni, M., Reyt, M., Dourte, M., de Haan, S., Lesoinne, A., Vandewalle, G., Phillips, C., Berthomier, C., Maquet, P., Muto, V., Hammad, G., Schmidt, C., & Baillet, M. (22 June 2024). Circadian rapid eye movement sleep expression is associated with brain microstructural integrity in older adults. Communications Biology, 7 (1), 758. doi:10.1038/s42003-024-06415-y
Peer Reviewed verified by ORBi

Hammad, G., Wulff, K., Skene, D. J., Münch, M., & Spitschan, M. (2024). Open-Source Python Module for the Analysis of Personalized Light Exposure Data from Wearable Light Loggers and Dosimeters. LEUKOS - Journal of Illuminating Engineering Society of North America, 1-10. doi:10.1080/15502724.2023.2296863
Peer Reviewed verified by ORBi

Spitschan, M., Hammad, G., Blume, C., Schmidt, C., Skene, D. J., Wulff, K., Santhi, N., Zauner, J., & Münch, M. (2024). Metadata recommendations for light logging and dosimetry datasets. BMC digital health, 2 (1), 73. doi:10.1186/s44247-024-00113-9
Peer reviewed

Beliy, N., Guillemin, C., Pommier, E., Hammad, G., & Phillips, C. (04 December 2023). Bidsme: expandable BIDS-ifier of brain imagery datasets. Journal of Open Source Software, 8 (92), 5575. doi:10.21105/joss.05575
Peer Reviewed verified by ORBi

Deantoni, M.* , Reyt, M.* , Baillet, M., Dourte, M., de Haan, S., Lesoinne, A., Vandewalle, G., Maquet, P., Berthomier, C., Muto, V., Hammad, G.* , & Schmidt, C.*. (2023). Napping and circadian sleep-wake regulation during healthy aging. Sleep. doi:10.1093/sleep/zsad287
Peer Reviewed verified by ORBi
* These authors have contributed equally to this work.

Deantoni, M., Reyt, M., Berthomier, C., Muto, V., Hammad, G., de Haan, S., Dourte, M., Taillard, J., Lambot, E., Cajochen, C., Reichert, C. F., Maire, M., Baillet, M.* , & Schmidt, C.*. (2023). Association between circadian sleep regulation and cortical gyrification in young and older adults. Sleep. doi:10.1093/sleep/zsad094
Peer Reviewed verified by ORBi
* These authors have contributed equally to this work.

Deantoni, M.* , Baillet, M.* , Hammad, G.* , Berthomier, C., Reyt, M., Jaspar, M., Meyer, C., Van Egroo, M., Talwar, P., Lambot, E., Chellappa, S. L., Degueldre, C., Luxen, A., Salmon, E., Balteau, E., Phillips, C., Dijk, D.-J., Vandewalle, G., Collette, F., ... Schmidt, C.*. (29 March 2023). Association between sleep slow-wave activity and in-vivo estimates of myelin in healthy young men. NeuroImage, 272, 120045. doi:10.1016/j.neuroimage.2023.120045
Peer Reviewed verified by ORBi
* These authors have contributed equally to this work.

Reyt, M., Deantoni, M., Baillet, M., Lesoinne, A., Laloux, S., Lambot, E., Demeuse, J., Calaprice, C., Le Goff, C., Collette, F., Vandewalle, G., Maquet, P., Muto, V., Hammad, G.* , & Schmidt, C.*. (29 July 2022). Daytime rest: Association with 24-h rest-activity cycles, circadian timing and cognition in older adults. Journal of Pineal Research, e12820, 1-11. doi:10.1111/jpi.12820
Peer Reviewed verified by ORBi
* These authors have contributed equally to this work.

Guillemin, C., Hammad, G., Read, J., Requier, F., Charonitis, M., Delrue, G., Vandeleene, N., LOMMERS, E., Maquet, P., & Collette, F. (June 2022). Pupil response speed as a marker of cognitive fatigue in early Multiple Sclerosis. Multiple Sclerosis and Related Disorders, 65, 104001. doi:10.1016/j.msard.2022.104001
Peer Reviewed verified by ORBi

Hammad, G., Reyt, M., Beliy, N., Baillet, M., Deantoni, M., Lesoinne, A., Muto, V., & Schmidt, C. (19 October 2021). pyActigraphy: Open-source python package for actigraphy data visualization and analysis. PLoS Computational Biology, 17 (10), 1009514. doi:10.1371/journal.pcbi.1009514
Peer Reviewed verified by ORBi

Muto, V.* , Koshmanova, E.* , Ghaemmaghami Tabrizi, P.* , Jaspar, M., Meyer, C., Elansary, M., Van Egroo, M., Chylinski, D., Berthomier, C., Brandewinder, M., Mouraux, C., Schmidt, C., Hammad, G., Coppieters, W., Ahariz, N., Degueldre, C., Luxen, A., Salmon, E., Phillips, C., ... Vandewalle, G. (16 July 2021). Alzheimer’s disease genetic risk and sleep phenotypes: association with more slow-waves and daytime sleepiness. Sleep, 44 (1), 137. doi:10.1093/sleep/zsaa137
Peer Reviewed verified by ORBi
* These authors have contributed equally to this work.

Narbutas, J., Van Egroo, M., Chylinski, D., Villar Gonzalez, P., Garcia Jimenez, C., Besson, G., Ghaemmaghami Tabrizi, P., Hammad, G., Muto, V., Schmidt, C., Luxen, A., Salmon, E., Maquet, P., Bastin, C., Vandewalle, G., & Collette, F. (2019). Cognitive efficiency in late midlife is linked to lifestyle characteristics and allostatic load. Aging, 11, 7169-7186. doi:10.18632/aging.102243
Peer Reviewed verified by ORBi

Scientific congresses and symposiums

Published communications

Hammad, G., Baillet, M., Reyt, M., Deantoni, M., Laloux, S., de Haan, S., Dourte, M., Muto, V., & Schmidt, C. (2024). Habitual napping in ageing; sex-specific associations with fractal motor activity regulation and hypothalamic integrity. Journal of Sleep Research. Supplement. doi:10.1111/jsr.14392
Peer reviewed

Schmidt, C., Reichert, C., Deantoni, M., Reyt, M., Maire, M., Gaggioni, G., Vandewalle, G., Collette, F., Cajochen, C., Hammad, G., & Muto, V. (26 September 2018). Age-related changes in circadian sleep-wake regulation: Impact on cognitive performance and cerebral correlates. Journal of Sleep Research. Supplement, Volume 27 (S1).
Peer reviewed

Oral communications or posters

Patino Rana, D., Talwar, P., Zubkov, M., Gasparello, A., Mortazavi, N., Beckers, E., Robert, A., Schmidt, C., Hammad, G., & Vandewalle, G. (2025). FRACTALz- Fractal Dynamics as a Diagnostic Tool in Alzheimer’s Disease [Poster presentation]. MaRBEL congress, Liège, Belgium.
Peer reviewed

Gasparello, A., Talwar, P., Zubkov, M., Beckers, E., Mortazavi, N., Hammad, G., Spruyt, M., Patino Rana, D., Schmidt, C., & Vandewalle, G. (2025). Pre-clinical manifestations of Parkinson’s disease: Locus coeruleus, sleep, genetics and cognition [Poster presentation]. MaRBEL congress, Liège, Belgium.
Peer reviewed

Dourte, M., Hammad, G., de Haan, S., Reyt, M., Deantoni, M., Baillet, M., Peigneux, P., & Schmidt, C. (27 September 2024). Napping and episodic memory performance in healthy older adults: a one-year interventional study [Paper presentation]. Sleep Europe 2024, Séville, Spain.
Peer reviewed

Dourte, M., Hammad, G., de Haan, S., Reyt, M., Deantoni, M., Baillet, M., Peigneux, P., & Schmidt, C. (27 September 2024). Regular napping and episodic memory performance in healthy older adults: a one-year intervention study [Paper presentation]. Sleep Europe 2024, Séville, Spain.
Peer reviewed

de Haan, S., Dourte, M., Reyt, M., Deantoni, M., Baillet, M., Berthomier, C., Muto, V., Hammad, G., Cajochen, C., Reichert, C. F., Maire, M., Schmidt, C., & Postnova, S. (September 2024). Impact of varying sleep pressure levels on sleep propensity in healthy young and older adults [Poster presentation]. ESRS 2024, Seville, Spain.
Editorial reviewed

de Haan, S., Dourte, M., Deantoni, M., Reyt, M., Baillet, M., Muto, V., Hammad, G., Berthomier, C., Cajochen, C., Reichert, C., Maire, M., Schmidt, C., & Svetlana, P. (04 September 2023). Modelling of daytime sleep under a napping protocol [Poster presentation]. GIGA Day, Liège, Belgium.

Charonitis, M., Guillemin, C., Hammad, G., & Collette, F. (10 August 2023). The effects of cognitive load on cognitive fatigue across the lifespan [Poster presentation]. SARMAC 2023, Nagoya, Japan.
Peer reviewed

Dourte, M., Deantoni, M., Reyt, M., Baillet, M., de Haan, S., Muto, V., Christian, B., Peigneux, P., Hammad, G., & Schmidt, C. (01 June 2023). Effect of daytime napping on skin-temperature regulation and sleep in healthy older adults [Paper presentation]. 34th Annual Meeting of the Society for Light Treatment and Biological Rhythms (SLTBR), Lausanne, Switzerland.
Peer reviewed

Dourte, M., Deantoni, M., Reyt, M., Baillet, M., de Haan, S., Lesoinne, A., Muto, V., Peigneux, P., Hammad, G., & Schmidt, C. (2023). Thermoregulation, sleep dynamics and napping in the aged [Poster presentation]. GIGA-Day 2023.
Peer reviewed

Dourte, M., Hammad, G., Schmidt, C., & Peigneux, P. (2023). Circadian rhythm of temperature and visuospatial working memory in aging [Poster presentation]. NEUROCOG 2023.
Peer reviewed

Dourte, M., Deantoni, M., Reyt, M., Baillet, M., de Haan, S., Lesoinne, A., Berthomier, C., Muto, V., Peigneux, P., Hammad, G., & Schmidt, C. (24 November 2022). Siestes chroniques et modulation de la température corporelle dans le vieillissement [Paper presentation]. Congrès du Sommeil, Lille, France.
Editorial reviewed

de Haan, S., Baillet, M., Deantoni, M., Reyt, M., Dourte, M., Muto, V., Phillips, C., MAQUET, P., Berthomier, C., Postnova, S., Schmidt, C., & Hammad, G. (27 September 2022). Modelling age-related changes in human sleep across the 24h-cycle: impact of circadian amplitude and wake-promoting inputs to the monoaminergic system [Poster presentation]. Sleep Europe 2022, Athens, Greece.
Editorial reviewed

Dourte, M., Deantoni, M., Reyt, M., Lesoinne, A., Muto, V., Baillet, M., de Haan, S., Peigneux, P., Hammad, G., & Schmidt, C. (27 September 2022). Thermoregulation, sleep efficiency and napping in the elderly [Poster presentation]. SLEEP EUROPE 2022, Athènes, Greece.
Peer reviewed

Dourte, M., Deantoni, M., Reyt, M., Muto, V., Baillet, M., de Haan, S., Peigneux, P., Hammad, G., & Schmidt, C. (07 September 2022). Napping and daily modulation in body temperature and sleep efficiency during healthy aging [Poster presentation]. GIGA Day, Liège, Belgium.
Editorial reviewed

de Haan, S., Baillet, M., Deantoni, M., Reyt, M., Dourte, M., Muto, V., Phillips, C., Maquet, P., Berthomier, C., Postnova, S., Schmidt, C.* , & Hammad, G.*. (06 September 2022). Modelling age-related changes in human sleep across the 24h-cycle: impact of circadian amplitude and wake-promoting inputs to the monoaminergic system [Poster presentation]. GIGA Day, Liège, Belgium.
Editorial reviewed
* These authors have contributed equally to this work.

Reyt, M., Deantoni, M., Baillet, M., Lesoinne, A., Laloux, S., Lambot, E., Demeuse, J., Calaprice, C., Le Goff, C., Collette, F., Vandewalle, G., Maquet, P., Muto, V., Hammad, G.* , & Schmidt, C.*. (September 2022). Daytime rest, circadian timing and cognitive performance in healthy older adults [Poster presentation]. The 26th Congress of the European Sleep Research Society, Athènes, Greece.
Peer reviewed
* These authors have contributed equally to this work.

Reyt, M., Deantoni, M., Baillet, M., Lesoinne, A., Laloux, S., Collette, F., Muto, V., Hammad, G., & Schmidt, C. (September 2022). Chronic napping alters cognitive performance in healthy older adults [Paper presentation]. The 26th Congress of the European Sleep Research Society, Athènes, Greece.
Peer reviewed

Hammad, G., Reyt, M., Baillet, M., Deantoni, M., de Haan, S., Lesoinne, A., Laloux, S., Lambot, E., Muto, V., & Schmidt, C. (July 2022). Fractal regulation of human motor activity, hypothalamic integrity and napping during ageing [Poster presentation]. European Biological Rhythms Society (EBRS) Congress, Zürich, Switzerland.
Editorial reviewed

Dourte, M., Grignard, M., Hammad, G., Schmidt, C., & Peigneux, P. (03 June 2022). Circadian rhythm of temperature and visuospatial working memory in aging [Poster presentation]. BAPS Annual Meeting 2022, Leuven, Belgium.

Guillemin, C., Requier, F., Delvenne, J., Hammad, G., DELRUE, G., LOMMERS, E., Maquet, P., & Collette, F. (28 May 2021). The effects of cognitive load on cognitive fatigue in Multiple Sclerosis - Preliminary results [Poster presentation]. BAPS 2021 Annual Meeting.

Dourte, M., Reyt, M., Deantoni, M., Lesoinne, A., Muto, V., Baillet, M., Hammad, G., & Schmidt, C. (21 May 2021). Repos diurne, perturbation circadienne et mémoire chez les personnes âgées [Poster presentation]. Journées d'Etude du Vieillissement, Lyon, France.

Koshmanova, E., Muto, V., Jaspar, M., Meyer, F., Grignard, M., Hammad, G., Berthomier, C., Brandewinder, M., Luxen, A., Degueldre, C., Salmon, E., Phillips, C., Posthuma, D., Georges, M., Schmidt, C., Maquet, P., van Someren, E., & Vandewalle, G. (22 September 2020). Higher polygenic risk for insomnia is associated with lower delta power during habitual sleep in young individuals without sleep disorders [Poster presentation]. 25th Congress of the European Sleep Research Society (ESRS) 2020.
Peer reviewed

Deantoni, M., Muto, V., Hammad, G., Berthomier, C., Baillet, M., Reyt, M., Jaspar, M., Meyer, C., Vanegroo, M., Lambot, E., Chellappa, S. L., Brandewinder, M., Degueldre, C., Luxen, A., SALMON, E., Phillips, C., Balteau, E., Collette, F., Dijk, D.-J., ... Schmidt, C. (22 September 2020). Association between sleep regulation and neuroimaging-derived myelin markers [Paper presentation]. 25th Congress of the European Sleep Research Society ESRS.

Hammad, G., Reyt, M., Baillet, M., Deantoni, M., Lesoinne, A., Laloux, S., Lambot, E., Muto, V., & Schmidt, C. (September 2020). Fractal regulation of human motor activity and its manifestation at circadian and ultradian time scales [Poster presentation]. European Sleep Research Society.

Reyt, M., Deantoni, M., Lesoinne, A., Baillet, M., Lambot, E., Laloux, S., Muto, V., Hammad, G., & Schmidt, C. (September 2020). It's about time: resting during daytime alters attention in the aged [Poster presentation]. European Sleep Research Society.

Hammad, G., Reyt, M., Beliy, N., Baillet, M., Deantoni, M., Lesoinne, A., Muto, V., & Schmidt, C. (September 2020). pyActigraphy, an open-source python package for actigraphy data visualisation and analysis [Poster presentation]. European Sleep Research Society.

Guillemin, C., Requier, F., Delvenne, J., Hammad, G., DELRUE, G., LOMMERS, E., Maquet, P., & Collette, F. (29 May 2020). Conséquences de la charge mentale sur la fatigue cognitive dans la Sclérose en Plaques - Résultats préliminaires [Poster presentation]. 44ème Journée de Printemps 2020 de la Société de Neuropsychologie de Langue Française (SNLF).

Reyt, M., Deantoni, M., Collette, F., Lesoinne, A., Baillet, M., Laloux, S., Lambot, E., SALMON, E., Phillips, C., Bahri, M. A., Muto, V., Hammad, G., & Schmidt, C. (2020). Impact of wake fragmentation on working memory performance and associated cerebral correlates in the aged [Paper presentation]. European Sleep Research Society.

Baillet, M., Reyt, M., Deantoni, M., Lesoinne, A., Laloux, S., Lambot, E., Berthomier, C., Brandewinder, M., Salmon, E., Balteau, E., Phillips, C., Bastin, C., Muto, V., Hammad, G., & Schmidt, C. (2020). Association between daytime rest, night-time sleep and hippocampal integrity in healthy older adults [Poster presentation]. European Sleep Research Society.

Lesoinne, A., Reyt, M., Deantoni, M., Baillet, M., Laloux, S., Lambot, E., Hammad, G., Muto, V., & Schmidt, C. (2020). Impact of napping and sleep-education on daytime functioning in older adults [Poster presentation]. 25th Congress of the European Sleep Research Society.

Narbutas, J., Van Egroo, M., Chylinski, D., Villar Gonzalez, P., Garcia Jimenez, C., Hagelstein, C., Lambot, E., Besson, G., Ghaemmaghami Tabrizi, P., Hammad, G., Muto, V., Schmidt, C., Salmon, E., Maquet, P., Bastin, C., Vandewalle, G., & Collette, F. (14 May 2019). Cognitive efficiency in late midlife is linked to cognitive reserve and allostatic load [Poster presentation]. BAPS 2019, Liège, Belgium.

Reyt, M., Latteur, A., Schmidt, C., Muto, V., & Hammad, G. (23 November 2018). La sieste comme indice de fragmentation du cycle de veille-sommeil : impact sur la cognition [Paper presentation]. Le Congrès du Sommeil, Lille, France.

Narbutas, J., Van Egroo, M., Chylinski, D., Villar Gonzalez, P., Hagelstein, C., Lambot, E., Besson, G., Ghaemmaghami Tabrizi, P., Hammad, G., Gaggioni, G., Muto, V., Schmidt, C., Salmon, E., Maquet, P., Bastin, C., Vandewalle, G., & Collette, F. (19 October 2018). Cognitive efficiency in late midlife is linked to cognitive reserve and heart rate variability [Poster presentation]. Belgian Brain Congress 2018, Liège, Belgium.

Narbutas, J., Van Egroo, M., Chylinski, D., Villar Gonzalez, P., Boraita-Amador, G., Muto, V., Hammad, G., Besson, G., Lambot, E., Laloux, S., Hagelstein, C., Degueldre, C., Schmidt, C., MAQUET, P., SALMON, E., Phillips, C., Bahri, M. A., Bastin, C., Collette, F., & Vandewalle, G. (27 September 2018). Sleep-wake fragmentation is linked to amyloid beta brain deposition in healthy ageing [Paper presentation]. 24th Congress of the European Sleep Research Society, Basel, Switzerland.

Hammad, G., Muto, V., Gaggioni, G., Jaspar, M., Meyer, C., Maquet, P., Schmidt, C., Phillips, C., & Coppieters't Wallant, D. (26 September 2018). New spectral analysis method to identify trait-like features in NREM sleep power spectra [Paper presentation]. 24th Congress of the European Sleep Research Society (ESRS), Basel, Switzerland.

Reyt, M., Latteur, A., Maire, M., Reichert, C., Cajochen, C., Schmidt, C., Muto, V., & Hammad, G. (26 September 2018). Impact of age and napping on actimetry-derived sleep and 24-h rest-activity indices [Poster presentation]. 24th Congress of the European Sleep Research Society (ESRS), Basel, Switzerland.

Narbutas, J., Van Egroo, M., Chylinski, D., Villar Gonzalez, P., Hagelstein, C., Lambot, E., Besson, G., Ghaemmaghami Tabrizi, P., Hammad, G., Gaggioni, G., Muto, V., Schmidt, C., Salmon, E., Maquet, P., Bastin, C., Vandewalle, G., & Collette, F. (14 September 2018). Cognitive efficiency in late midlife is linked to cognitive reserve and heart rate variability [Paper presentation]. 20th EURON PhD days, Brussels, Belgium.

Deantoni, M., Hammad, G., Maire, M., Ali Bahri, M., Berthomier, C., Cajochen, C., Reichert, C., & Schmidt, C. (September 2018). Association of circadian sleep-wake regulation and brain structure in older adults: a multi-modal approach [Paper presentation]. 24th Congress of the European Sleep Research Society (ESRS), Basel, Switzerland.

Hammad, G., Raty, J.-Y., & Ghosez, P. (March 2006). Structure and electronic properties of GeTe nanoparticles from ab initio calculations [Paper presentation]. 2006 March Meeting of the American Physical Society, Baltimore, United States.
Editorial reviewed

Other publications and communications

Computer developments

Hammad, G., Reyt, M., & Schmidt, C. (2019). pyActigraphy. Zenodo. doi:10.5281/zenodo.2537921

Speeches and writings for a general audience

Others

Muto, V., Schmidt, C., & Hammad, G. (2018). Atelier sur le sommeil pour enfants [Paper presentation]. Atelier de sommeil dans le cadre d'un stage d'été pour enfants, Malmedy, Belgium.

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