Changes in the kinesthetic content of dreams following somatosensory stimulation of leg muscles during REM sleep.

Abstract

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.

Nightmares and oxygen desaturations: is sleep apnea related to heightened nightmare frequency?

“…As the application of external stimuli has a marked effect on dream content [incorporation rates varying from 9% (sinus tone; [26]) to 87% (blood pressure cuff on the legs; [27])], it is extraordinary that the intense internal stimuli of "sleep apnea" so rarely affects dream content. Schredl et al [20] speculated that there might be an adaptation to this internal stimuli, which seems plausible as severity of the sleep apnea syndrome worsens over a long period of time.…”

Dream content of patients with sleep apnea

“…Stimuli such as sinus tones, flashes, words, olfactory stimuli, minor electroshocks, pressure stimuli were applied; the incorporation rates varied from 9 % (Sinus tone [3]) to 87 % (pressure stimuli [10]). These studies support the view that information from the sensory organs are at least partly processed by the sleeping brain, can be incorporated into the dream and, thus, be remembered upon awakening.…”

Towards an olfactory computer-dream interface

“…Wiseman however does state that a priming effect may be in place and that even when the app was playing no sound at all during the night, "many still dreamed about the scenery of their chosen soundscape" [12:49]. This could although, as other researchers have concluded, be due to the finding that sound stimuli are less effective than other stimuli, especially somatosensory stimuli at influencing the content of dreams [7,10]. In any case, Wiseman has created a platform that offers a first, yet limited, personally controllable interface for our dreams.…”