Effects of sleep deprivation on auditory change detection: a N1-mismatch negativity study.

The effects of sleep deprivation on neural activity underlying stimulus change detection are still debated. The aim of this study was to investigate the effects of sleep deprivation on the relationship between N1 refractoriness and Mismatch Negativity (MMN) as indexes of different stages of change detection. Respectively, N1 represents the sensory feature trace creation with stimulus repetition and MMN represents the memory-based detection of deviance in a new incoming stimulus. Event-related potentials (ERPs) were recorded from 22 healthy participants during a passive auditory oddball task after a night of normal sleep and after a night of total sleep deprivation (TSD). Importantly, stimulus presentation was organized as a train of 10 stimuli, so that N1 refractoriness could be measured as amplitude decrease with stimulus repetition within each train. Results showed that N1 refractoriness and MMN were not affected by TSD suggesting that the change detection process was preserved in our paradigm. However, the overall N1 amplitude increased after TSD, an effect that may be related to an enhancement of cortical excitability.