In an intensive single-subject design, electroencephalographic (EEG) a
lpha power and receptive and expressive language in dreaming were stud
ied in 12 dreams during rapid eye movement (REM) sleep on 12 separate
nights. Bilateral EEG was recorded continuously from 21 sites and digi
tized. We used the Fast Fourier transformation (FFT) for power spectra
l analysis to measure EEG power in the alpha frequency range (8-12 Hz)
at each of the EEG sites. The subject was awakened after about 14 min
utes into the second REM period, and dream reports were collected. We
scored the dream reports for expressive and receptive language. The lo
wer the alpha power on the left sides of those homologous pairs that r
oughly correspond to Broca's (C3) or Wernicke's area (P3), the more ex
pressive or receptive language in dream reports. The largest differenc
e between the correlation of the left and that of the right homologous
pair of regions was found in the central (C3, C4) area for expressive
language and in the parietal (P3, P4) area for receptive language. Ou
r finding suggests lateralized and localized cortical activation in re
lation to language in dreaming.