Changes in the Kinesthetic Content of Dreams Following Somatosensory Stimulatipn of Leg Muscles During REM Sleep

The notion that dreaming is isolated from sensory activity is chal/~ng~d by demonstrations that somatosensory stimuli are frequently incorporated illlo dreiUlI colllent. To further study such effects, four volunteers were administered pressure stimulation to either the left or the right leg during REM sleep and awakened to report tlu:ir dreams. These dreams were rated and compared to non-stimulated drcams. Stimulated dreams more frequently contained leg sensations and references to the pressure stimulus than did non-stimulated dreams; dreamed leg activity, but not dreamed arm activity, was also rated as more intense. Incorporations of the jjtinllllllS were typically simple, direct kinesthetic sensations of pressure or squeezing but were also sometimes embedded in more extended 'problem-solving' sequences. Stimulation also increased bodily biza"eness. The latter included change:,' in kinesthetic 'lulliity vf movement, instabilities of posture and the environment, as well as visual-kil/estlll:tic ~Yllthe~'ias. Although micro-arousals may be an explanatory factor, the re:,'ults sllggest that somato~'ensory ~.timulation influences 'kinesthetic fantasy', a dimension of dreumillg uj'~'ociated with both cel/tral and peripheral ~'ources of kinesthetic activity.