Abstract
Bilateral thermal lesions in the feline pontine tegmentum release elaborate behaviours during rapid eye movement sleep (REM). The behaviours, which are lesion-site specific, are consistent with the brain's paradoxical appearance of 'alertness' in REM and are largely isolated from environmental events, as are human dreams. This phenomenon may aid in understanding the neurophysiology underlying human dreams but offers little to the unravelling of their cognitive aspects.