In these dreams of failure of movement, it seems to me, the dream process, as the result of an approximation to the waking state, has become mixed with actual sensori-motor impulses, but the threshold of waking life is still too far off for actual movements to be completely and successfully accomplished, and in the case of the limbs the eye cannot be used to guide movements which the muscular and cutaneous sensations are still too dead to guide. It is important to remember that in waking life, under pathological conditions, we may have a precisely similar state of things. In some states of cerebro-spinal degeneration, resulting in defective sensibility of muscle and nerve, the subject sways unsteadily when he closes his eyes, and when there is loss of sensibility in the arm it is sometimes impossible to hold objects in the hand except with the guiding aid afforded by the eye.[81]
In a dream, dating from fifteen years back, that I now regard as conditioned by the approach of the moment of awakening, I imagined that I was making huge efforts to copy in a copy-book a capital H, engraved in a rather peculiar fashion, but really offering no difficulties to any waking schoolchild. By no means could I get the proportions right, if, indeed, I could make any stroke at all, and at the end of my painful and ineffectual efforts I seemed to be trying to write on sand, which was merely displaced by my hand. This final impression seems clearly to be that of a dreamer who is already sufficiently awake to be conscious of the bedclothes yielding to the touch.
The foregoing dream suggests that failure of movement in dreaming may tend to be associated with an accentuation of that shifting of imagery which is one of the most primary elements in dreaming, both failure of movement and accentuation of shifting imagery being, perhaps, alike due to the approach towards the waking state. Thus, if in a dream one is brushing one's coat, one finds, without any overwhelming surprise, that fresh patches of dust appear again and again, even when one's efforts in brushing them away are successful. Even when we feel able to effect movement in our dream, there may still be a failure of that movement to effect its object.
The question of movement in dreams, of the presence or absence of effort and inhibition, is thus seen to be explicable by reference to the depth of sleep and the particular groups of centres involved. In full normal sleep movements are purely ideatory, and no difficulty arises in executing any movement, for the reason that there really is no movement at all, or even any attempt at movement, while, even if slight movement occurs, no message of its actual defectiveness can reach the brain. Movement or attempt at movement, with more or less inhibition, tends to occur when the motor and sensory centres are in a partially aroused state; it is a phenomenon which belongs to the period immediately before awakening.[82]
It is doubtless mainly due to the diffusion of inhibited nervous impulses through many channels, and the vague and massive character which they hence assume in consciousness, that we must attribute the magnification of dream imagery, and the exaggeration of dream feelings. This is not a constant tendency of our dreams; sometimes, indeed, perhaps in special stages of sleep-consciousness, there is diminution, and people look no larger than dolls, and houses like doll's houses, while, on the emotional side, events which in real life would overwhelm us, may, in dreams, be accepted as matters of course. But the heightening of imagery and ideas and feelings is very common. There is a kind of normal megalomania in our dreams. We have already incidentally encountered many instances of this: a tooth appears large enough for a mouse to play in, or like a great jagged rock; the irritation of a mosquito evokes the image of a huge scarlet beetle; in vesical dreams endless streams are seen to flow; a canary's song is heard as Haydn's Creation, and the howling of the wind becomes a chanted Te Deum.
A French author has written an impressive literary description of his own purely visual dreams, with their magnificent exaggerations and joyous expansiveness, seeking to show that their chief character is their excessiveness; 'the flowers are almost women.'[83] I cannot, however, recognise this as characteristic of normal dreaming. It bears more resemblance to De Quincey's opium dreams, or to the visions which came to Heine as he listened to Berlioz's music. In normal dreaming the imagery may, indeed, be stupendously vast, or fantastically absurd, or poignantly intense. But normal dreams are not built on a consistently colossal scale. The megalomania of dreaming is only accidental and occasional, not systematic.[84]
The heightening of dream experiences may, however, be very complete in, as it were, every direction: thus a botanical friend joined a large party for a pleasant country excursion, in the course of which, while sitting in a waggonette, an acquaintance, a miller, standing in the road, handed up to him a dog-rose. In the course of a dream of agreeable emotional tone on the night following, this incident was reproduced, but the miller had become an angel, who handed down to him, instead of up from below, a flower which was a moss-rose.
Thus, not only do the actual stimuli taking place during sleep suggest to dream-consciousness imagery of a magnitude out of all proportion to their real intensity, but even the repercussion of the day's incidents in dreams under the influence of a favourable emotional tone may partake of the same heightening influence.
We may say, therefore, that while the excessiveness of dream imagery is mainly due to the conditions of the nervous sensory and motor channels, there is also probably a heightened affectability of the cerebral centres themselves—perhaps due to their state of dissociation or absence of apperception[85]—which leads us in our dreams to react extravagantly to the stimuli that reach the brain. A lady tells me that she often dreams of being very angry at things which, on awaking, she finds are mere trifles that would never make her angry when awake.[86] It is a common experience that the things which, in our dreams, impress us as beautiful, eloquent, witty, profound, or amusing, no longer seem so, or only seem so in a much slighter degree, when we are able to recall them awake.
All these various considerations lead us up to a central fact in the psychology of dreaming: the controlling power of emotion on dream ideas. From our present point of view we are now able to say that the chief function of dreams is to supply adequate theories to account for the magnified emotional impulses which are borne in on sleeping consciousness. This is the key to imagination in dreams. From the first we have seen that in dream life the mind is always freely and actively reasoning; we now see what is usually the real motive and aim of that reasoning. Sleeping consciousness is assailed by waves of emotion from various parts of the organism, but is entirely unable to detect their origin, and, therefore, invents an explanation of them. So that in sleep we have to weave theories concerning the unknowable origin of our emotions, just as when we are awake we weave theories concerning the ultimate origin of the totality of our experiences. The fundamental source of our dream life may thus be said to be emotion.[87]