title: Circadian preference modulates the neural substrate of conflict processing across the day.
abstract: Human morning and evening chronotypes differ in their preferred timing for sleep and wakefulness, as well as in optimal daytime periods to cope with cognitive challenges. Recent evidence suggests that these preferences are not a simple by-product of socio-professional timing constraints, but can be driven by inter-individual differences in the expression of circadian and homeostatic sleep-wake promoting signals. Chronotypes thus constitute a unique tool to access the interplay between those processes under normally entrained day-night conditions, and to investigate how they impinge onto higher cognitive control processes. Using functional magnetic resonance imaging (fMRI), we assessed the influence of chronotype and time-of-day on conflict processing-related cerebral activity throughout a normal waking day. Sixteen morning and 15 evening types were recorded at two individually adapted time points (1.5 versus 10.5 hours spent awake) while performing the Stroop paradigm. Results show that interference-related hemodynamic responses are maintained or even increased in evening types from the subjective morning to the subjective evening in a set of brain areas playing a pivotal role in successful inhibitory functioning, whereas they decreased in morning types under the same conditions. Furthermore, during the evening hours, activity in a posterior hypothalamic region putatively involved in sleep-wake regulation correlated in a chronotype-specific manner with slow wave activity at the beginning of the night, an index of accumulated homeostatic sleep pressure. These results shed light into the cerebral mechanisms underlying inter-individual differences of higher-order cognitive state maintenance under normally entrained day-night conditions.
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Christina
authors.initials: C
authors.lastname: Schmidt
authors.forename: Philippe
authors.initials: P
authors.lastname: Peigneux
authors.forename: Yves
authors.initials: Y
authors.lastname: Leclercq
authors.forename: Virginie
authors.initials: V
authors.lastname: Sterpenich
authors.forename: Gilles
authors.initials: G
authors.lastname: Vandewalle
authors.forename: Christophe
authors.initials: C
authors.lastname: Phillips
authors.forename: Pierre
authors.initials: P
authors.lastname: Berthomier
authors.forename: Christian
authors.initials: C
authors.lastname: Berthomier
authors.forename: Gilberte
authors.initials: G
authors.lastname: Tinguely
authors.forename: Steffen
authors.initials: S
authors.lastname: Gais
authors.forename: Manuel
authors.initials: M
authors.lastname: Schabus
authors.forename: Martin
authors.initials: M
authors.lastname: Desseilles
authors.forename: Thanh
authors.initials: T
authors.lastname: Dang-Vu
authors.forename: Eric
authors.initials: E
authors.lastname: Salmon
authors.forename: Christian
authors.initials: C
authors.lastname: Degueldre
authors.forename: Evelyne
authors.initials: E
authors.lastname: Balteau
authors.forename: André
authors.initials: A
authors.lastname: Luxen
authors.forename: Christian
authors.initials: C
authors.lastname: Cajochen
authors.forename: Pierre
authors.initials: P
authors.lastname: Maquet
authors.forename: Fabienne
authors.initials: F
authors.lastname: Collette
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001931:Brain Mapping; D002909:Chronobiology Phenomena / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D003220:Conflict, Psychological; D055724:Electrophysiological Phenomena; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006184:Habits; D006801:Humans; D007206:Individuality; D008279:Magnetic Resonance Imaging; D008297:Male; D017008:Negotiating / Q000523:psychology*; D009474:Neurons / Q000378:metabolism*; D012890:Sleep / Q000502:physiology; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult
chemical_list: D015415:Biomarkers