Based on observations in five patients, we review the main theories concerning dreams and propose a comprehensive theory on their cognitive function. We classify dreams based on the role performed by them in inhibition, stimulation or creation of cognitive strategies around an emotional nucleus. These are stored in the memory bank and retrieved by an elicitation mechanism linking affective experiences on awareness and the strategies processed in previous dreams. We also propose that the changes in logical and emotional patterns in dreams are based on fronto-limbic dominance oscillations during each REM period. Preliminary observations we made show that awakening patients during most rapid frontal EEG activity during REM sleep elicits more logical and less bizarre dreams. Contrariwise, when they are awakened during slower REM cortical EEG activity, mainly over the frontal lobes, their dreams are more bizarre and consequently less elaborated from a cognitive point of view.
dream; neuropsychology; electroencephalography