Combined effects of moderate normobaric hypoxia and sleep restriction on visual and auditory integration

Figures

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  Fig. 1. Visual and auditory P300 amplitudes are decreased during sleep restriction, while only visual P300 latencies are increased by both constraints. (a) Topographical representation of event-related potentials (µV) at 300 ms from stimulus onset (P300), during the Psychomotor Vigilance Task (PVT) and for the four experimental conditions. HSNO habitual sleep and NOrmoxia, HSHY habitual sleep and HYpoxia, SRNO sleep restriction and NOrmoxia, SRHY sleep restriction and HYpoxia. (b) and c) P300 amplitudes and latencies respectively over parieto-occipital regions for all experimental conditions. (d-f) Same as (a-c) during the auditory oddball. Amplitudes and latencies were calculated over centro-parietal regions. Error bars represent standard error. Statistical differences from HSNO (*): ** p < 0.01, *** p < 0.001, Statistical differences from HSHY ($): $$ p < 0.01, $$$ p < 0.001, Statistical differences from SRNO (#): ### p < 0.001

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  Fig. 2. Visual and auditory alpha power and alpha inter-trial precision are differentially impaired by hypoxia and sleep restriction. (a) Time-frequency representation (-0.3 ms to + 0.7 ms) of alpha band (7–13 Hz) power (µV²) for all conditions. (b) Event-related desynchronization of alpha band power (ERD), the more negative the better alpha desynchronization. (c) Time-frequency representation of alpha band inter-trial phase coherence (ITPC, arbitrary unit) for all conditions and its quantification in (d). (e-h) Same as A-D) during the auditory oddball. Error bars represent standard error. Statistical differences from HSNO (*): ** p < 0.01, *** p < 0.001, Statistical differences from HSHY ($): $$ p < 0.01, $$$ p < 0.001

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  Fig. 3. Pre-stimulus alpha power and frequency during the PVT and the auditory oddball. (a-c) Assessment of lower alpha band (7–10 Hz) relative power (%), upper alpha band (10–13 Hz) relative power (%) and individual alpha frequency (IAF, Hertz (Hz)) respectively during the PVT. (d-f) Same as (a-c) during the auditory oddball. Statistical differences from HSNO (*): * p < 0.05, ** p < 0.01, *** p < 0.001, Statistical differences from HSHY ($): $ p < 0.05, $$ p < 0.01, $$$ p < 0.001, Statistical differences from SRNO (#): # p < 0.05, ## p < 0.01, ### p < 0.001

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  Fig. 4. Experimental protocol. TIB: time in bed, FiO2 Fraction of inspired oxygen, HS Habitual Sleep, SR Sleep restriction, NO Normoxia, HY Hypoxia, PVT psychomotor vigilance task.