Elsevier

NeuroImage

Volume 16, Issue 1, May 2002, Pages 251-258
NeuroImage

Regular Article
Altered Processing of Acoustic Stimuli during Sleep: Reduced Auditory Activation and Visual Deactivation Detected by a Combined fMRI/EEG Study

https://doi.org/10.1006/nimg.2002.1071Get rights and content

Abstract

Although there is evidence that acoustic stimuli are processed differently during sleep and wakefulness, little is known about the underlying neuronal mechanisms. In the present study, the processing of an acoustic stimulus was investigated during different non rapid eye movement (NREM) sleep stages using a combined EEG/fMRI approach in healthy human volunteers: A text stimulus was presented to sleep-deprived subjects prior to and after the onset of sleep, and single-slice silent fMRI were acquired. We found significantly different blood oxygenation level-dependent (BOLD) contrast responses during sleep compared to wakefulness. During NREM sleep stages 1 and 2 and during slow wave sleep (SWS) we observed reduced activation in the auditory cortex and a pronounced negative signal in the visual cortex and precuneus. Acoustic stimulation during sleep was accompanied by an increase in EEG frequency components in the low delta frequency range. Provided that neurovascular coupling is not altered during sleep, the negative transmodal BOLD response which is most pronounced during NREM sleep stages 1 and 2 reflects a deactivation predominantly in the visual cortex suggesting that this decrease in neuronal activity protects the brain from the arousing effects of external stimulation during sleep not only in the primary targeted sensory cortex but also in other brain regions.

References (28)

  • K. Carlsson et al.

    Tickling expectations: Neural processing in anticipation of a sensory stimulus source

    J. Cog. Neurosci.

    (2000)
  • W.C. Drevets et al.

    Blood flow changes in human somatosensory cortex during anticipated stimulation

    Nature

    (1995)
  • S.D. Forman et al.

    Improved assessment of significant activation in functional magnetic resonance imaging (fMRI): Use of a cluster-size threshold

    Magn. Reson. Med.

    (1995)
  • Cited by (0)

    This work was in part presented at the 9th scientific meeting of the International Society for Magnetic Resonance in Medicine, 21–27 April 2001, Glasgow, Scotland, UK.

    2

    These authors contributed equally.

    View full text