Abstract
illustrates that the development of brain imaging techniques such as positron emission tomography (PET), computed tomography (CT), and magnetic resonance imaging (MRI) has made it possible to visualize the regional activation (and inactivation) patterns associated with changes in conscious state. It is shown that dreaming is characterised by a set of related, cognitive features that are deficient compared with waking, including diminished selfawareness, diminished reality testing, poor memory, defective logic, and, most strikingly, the inability to maintain directed thought. The effect of brain damage — especially strokes and epileptic seizures — on dreaming is also considered.
