Figure 1. Sleep Studies and Data Overview.
(A) Set-up for polysomnographic sleep recordings.
(B) Hypnogram: time-course ofsleep-wake stages in one representative individual. W, wake; R, REM sleep; N1-N3, NREM sleep, stages 1–3.
(C) Average power spectra of scalp EEG in the same individual computed separately in stages N2 (blue), N3 (red) and REM sleep (green). Note high power in slow wave (<4 Hz) and spindle (10–16 Hz) range in NREM sleep.
(D) Diagram of flexible probes used for concomitant recording of depth EEG (platinum contacts, blue) and unit activity (microwires, green).
(E) Overview of 129 depth electrode locationsin13 individuals encompassing multiple brain regions seen from medial view. Abbreviations: OF, orbitofrontal cortex; AC, anterior cingulate; SM, supplementary motor; PC/P, posterior cingulate / parietal cortex; PH, parahippocampal gyrus; HC, hippocampus; E, entorhinal cortex; Am, amygdala; L, left hemisphere; R, right hemisphere.
(F) Example of data acquired during 6 s of NREM sleep. Rows (top to bottom) show activity in scalp EEG (Cz, red), depth EEG (entorhinal cortex, blue), multiunit activity (MUA) in one microwire (green), and spiking activity in six isolated single-units (black bars).