<P> Brain energy use in REM sleep, as measured by oxygen and glucose metabolism, equals or exceeds energy use in waking . The rate in non-REM sleep is 11--40% lower . </P> <P> Neural activity during REM sleep seems to originate in the brain stem, especially the pontine tegmentum and locus coeruleus . REM sleep is punctuated and immediately preceded by PGO (ponto - geniculo - occipital) waves, bursts of electrical activity originating in the brain stem . (PGO waves have long been measured directly in cats but not in humans because of constraints on experimentation; however comparable effects have been observed in humans during "phasic" events which occur during REM sleep, and the existence of similar PGO waves is thus inferred .) These waves occur in clusters about every 6 seconds for 1--2 minutes during the transition from deep to paradoxical sleep . They exhibit their highest amplitude upon moving into the visual cortex and are a cause of the "rapid eye movements" in paradoxical sleep . Other muscles may also contract under the influence of these waves . </P> <P> Research in the 1990s using positron emission tomography (PET) confirmed the role of the brain stem and suggested that, within the forebrain, the limbic and paralimbic systems showed more activation than other areas . The areas activated during REM sleep are approximately inverse to those activated during non-REM sleep and display greater activity than in quiet waking . The "anterior paralimbic REM activation area" (APRA) includes areas linked with emotion, memory, fear and sex, and may thus relate to the experience of dreaming during REMS . More recent PET research has indicated that the distribution of brain activity during REM sleep varies in correspondence with the type of activity seen in the prior period of wakefulness . </P> <P> The superior frontal gyrus, medial frontal areas, intraparietal sulcus, and superior parietal cortex, areas involved in sophisticated mental activity, show equal activity in REM sleep as in wakefulness . The amygdala is also active during REM sleep and may participate in generating the PGO waves, and experimental suppression of the amygdala results in less REM sleep . The amygdala may also cardiac function in lieu of the less active insular cortex . </P>

Which functional brain area is activated during rem sleep (where we dream)
find me the text answering this question