Mismatch negativity during objective and subjective sleepiness


  • This study was supported in part by a grant to M. Sallinen from the Academy of Finland.

  • We thank Jakka Kaartinen. Timo Rossi, and Timo Russuvirta for their contribution to this study.


The mismatch negativity (MMN) and P.3 of auditory event related potentials were studied during subjectively and objectively (physiologically) defined sleepiness under optimal stimulus conditions for MMN elicitation. The MMN and P3 were elicited by either small or large unattended auditory deviants presented to the left ear The participant's task was to defect either rare auditory targets presented to the right ear or rare changes in the light Hashes Eleven young adults served as participants in a nighttime experiment. The MMN declined especially at Fz and Cz bin not so markedly at the right mastoid as either subjective or objective alertness decreased The amplitude of P3 also decreased during sleepiness The attenuation of the MMN was paralleled by a decline in behavioral performance The results show that the MMN is attenuated by a decrease in alertness even before an actual sleep stale is reached.