A Sleep Researcher Who Is Monitoring the Sleep of Volunteers

A sleep researcher who is monitoring the sleep of volunteers in the study notices that the electroencephalogram (EEG) of one person, who is sleeping quietly, is showing large peaks of activity at regular intervals.What is most likely occurring in the person's brain at the cellular level?

A) Cells in the thalamus and cortex are depolarized and are firing more action potentials.
B) Cortical cells are hyperpolarized, and the bursts of activity indicate slow-wave sleep.
C) The peaks indicate REM sleep and some depolarization of the brainstem.
D) Cells are responding to dreams that the person may be having and firing action potentials accordingly.
E) The peaks correspond to the activity of only a few neurons and do not indicate much about the overall cellular activity.