DREAMING (from dream. OS. drCon, Icel. drauni•, 011(;. /roam, I:er. Truism. dream: prob ably connected with 1111t:. Ger. t rii gen, Skt, drub. to deeeko, uPyr•. drool a lie). ln the profoundest there is. so far as we can tell, a total lapse (if mentation: the condition- of the formation of a conscionsnes- are not realized. There has been, it is true, much dispute as to whether the mental life is ever really extinguished in sleep; and we cannot deny the possibility of a tont inilance of ban / rganie sentiency, xvhielt is lust. on Avaking. in the richer ideation of the normal VI Put. however that may be, introspection gives 11' 1i° psychological warrant for the loll of mental process during deep skip. In the lighter stages of sleep. on the other hand. there is in termittent nictitation: we 'dream.' and the dream eonseiousness is. in large measure. accessible to 1.111' analysis.
It is probable that dreams. in the great ma jority of cases, are started by the stimulation of some sense-organ. and do not take their origin within the brain itself. XVc may darken our bedroom as we Will, hilt we eammt out the 'intrin-de gray' or 'light dust' of the retina: or the throbbing and buzzing of the blood eireulation in the ear: still le-- can we eliminate cutaneous and stimulation-. There i-, then. always the possibility of a sense.impres-ion its way to the brain during sleep. If. now. we keep our eyes clo-ed as we wake from a visual dream, we can often trace 1recnn paltvrn in the 112111 'lust that is seen upon the field of t he while, conversely. if we note the pattern of the light dust before we fall asleep, and then ourselves waked. we find that the dream has taken it- form and (diameter from the peripheral excitations. lIere is clear evi dence that the brain has received its dream-cue from the eye. Similar tests have been carried out. with similar though le-s strikilg result, upon the other sense-organs. As a general rule. then. the dream-eonseiousuess is started by some sensory stimuhts. though. having once orig inated, it may continue it course in obedience to the laws of association (q.v.) without any further interference from the outside.
We have supported this conclusion by an appeal to the eye; and the appeal has, doubtless, appeared quite natural. For dreams are pre dominantly visual: so strongly visual. indeed, that it is not rare to find them defined, in so many words. as 'trains of fantastic images.' There is good for this preponderance of visual mind-stuff in dreams: ( I) Most of us, in the waking life, are likely to think, imagine, and remenher in visual terms: we are 'eye minded.' It is evident that this ingrained habit of mind toward visualization must show itself in dreams. (2) The retina is in a constant
state of intrinsic excitation during sleep: the retinal gray and the light dust will, if only the chance he given them, make themselves known in sensation. (3) And the chance must he given them fairly frequently. For sight is the first sense to disappear. as sleep comes on, and the last sense to be regained on waking: so that the eye may be stimulated, during sleep, with a moderately high degree of intensity, while the sleeper is still not disturbed. Dreams, how ever, are by no means exclusively visual. Next in order of frequency to dreams of sight stand, perhaps, the dreams whose principal material is organic and temperature sensations. It is curious to note that dreams which are initiated by au organic sensation (a pain, a suffocation, a cramp) are oftentimes translated into terms of vision. A slight intercostal pain may be dreamed of 'in kind' as a dagger-thrust. or the bite of a muid dog: hut we shall probably see the dagger and the dog—and, in many cases, these will be the main objects of the dream. the organic sensation being present merely as a vague discomfort. So the rhythm of breathing may he 'seen' as a flight of birds or of angels: and an irritation of the skin may be 'seen' as a host of caterpillars or beetles crawling over us. This fact of translation into the language of sight has done much to divert attention from the very common occurrence of organic sensa tion in the dream-life. In the third for, as some authors would say. in the second) place, come dreams of hearing. Conversation is the one Iona of external stimulus that, in every-day life. approaches the visual stimuli of our sur roundings in regularity and insistency, and frag ments of conversation arc the most frequent auditory constituents of dreams. Sounds like the humming of bees and the clatter of musketry —the dream interpretations of the intrinsic noises of the ear—follow next in order. Tonal or musieal dreams ()emir, but are rare. Finally, the senses of smell, taste, and cutaneous pres sure may and do contribute elements to Our dreams: but these elements are extremely liable to visual translation, and appear but rarely in pure form.
The dream-consciousness is not confined, of course, to sensations. perceptions. and ideas. Every mental formation that is found in the waking life may be represented umr simulated) in the dreaming state. Thus the presence of emotion in dreams—surprise and excitement; fear and shame: disappointment and anger; Jealousy and perplexity—is a matter of experience. In deed, the appearance of emotion follows almost as a matter of cour,e from the large part played in dreaming by the organic seusa lions. (ScP