THE NUMEROUS anecdotal accounts of incorporations of naturally occurring external and internal stimuli (falling out of bed, thunder, stomachaches, etc) into dreams,1-4 as well as some early, systematic studies,5-7 attest to man's continuing interest in the nature of his commerce with the environment during sleep.
Dement and Wolpert8 studied the effects of three different types of stimuli (water spray, light, and pure tone) on dreams. They presented the various stimuli during rapid eye movement (REM) periods, the stage of sleep from which dream reports are most often elicited on awakening,9-12 and found the tactile stimulus (water) to be the most potent, being incorporated 42% of the time as compared to 9% for the tone and 23% for the light. Berger13 obtained over 50% incorporation for both meaningful and nonmeaningful names. The immense discrepancy between the amount of incorporation of an auditory