It is evident that my own sense of oppression, my own unconscious and involuntary movements in disturbing the bedclothes, were reconstructed by sleeping consciousness as the actions of an external person, in the second case, a supernatural creature, which, it is interesting to note, I duly accepted as such and addressed in the conventionally appropriate manner of old romance. The illusion may persist for some moments after waking. A lady, after breathing rather loudly and convulsively for a few seconds, wakes up, saying 'There is a rat or a mouse on the bed, shaking it up and down.' 'You were asleep,' her husband replied, 'as I knew by your breathing.' 'Oh, I was breathing like that,' she said, 'to make it jump off.' Here we see that, somewhat as in the previous cases, the dreamer's own muscular activity is, during sleep, reconstructed into the image of an external force; but when she is in the semi-waking hypnagogic stage, she recognises that the activity was her own, though still unable to dismiss the delusion based on the theory formed during sleep.
At this point we reach the threshold of hallucination, and the next case to be brought forward may be said to lie on the threshold, for an impression received in the hypnagogic (or hypnopompic) stage is accepted in its illusional form, even when the dreamer is fully awake. A farmer's daughter--a bright girl of twenty-one, with quick nervous reactions, but untrained mind--dreamed that she saw her brother (dead some years previously) with blood streaming from his fingers. She awoke in a fright, and was comforting herself with the thought that it was only a dream when she felt a hand grip her shoulder three times in succession. There was no one in the room, the door was locked, and no explanation seemed possible to her. She was very frightened, got up at once, dressed, and spent the rest of the night downstairs working. She was so convinced that a real hand had touched her that, although it seemed impossible, she asked her brothers if they had not been playing a trick on her. The nervous shock was considerable, and she was unable to sleep well for some weeks afterwards. She naturally knew nothing about abnormal psychic phenomena, and was utterly puzzled to explain the experience, except by supposing that it may have been a ghost. The explanation is really very simple. It is well recognised that involuntary muscular twitches may occur in the shoulder, especially after it has been subjected to pressure, and that in some cases such contractions may simulate a touch.[164] The dream of a bleeding hand indicates, when we bear in mind the tendency to objectify sensations symbolically, now familiar to us in dreaming, that the dreamer's arm was probably pressed beneath her in a cramped position.[165] This pressure would account, not only for the dream, but for the muscular twitches occurring on awakening. The nature of the dream, the terrified emotional state it produced, and the mental obscurity of the hypnagogic state, naturally combined, in a subject unaccustomed to self-analysis, to create an illusion which reflection is unable to dispel, though in the normal waking state she would probably have given no attention at all to such muscular twitches. Strictly speaking, such an experience is an illusion--that is to say, a misinterpretation of a real sensation--and not a hallucination--or perception without known objective causation--but there is no clear line of demarcation. In any case it may now be taken as proved that hallucinations tend to occur in the neighbourhood of sleep, and therefore to partake of the nature of dreams.[166]