Obviously, then, he is not blind to the kind of stroke in the least.He is blind only to one individual stroke of that kind in a particular position on the board or paper, -- that is, to a particular complex object;
and, paradoxical as it may seem to say so, he must distinguish it with great accuracy from others like it, in order to remain blind to it when the others are brought near.He 'apperceives' it, as a preliminary to not seeing it at all! How to conceive of this state of mind is not easy.It would be much simpler to understand the process, if adding new strokes made the first one visible.There would then be two different objects apperceived as totals, -- paper with one stroke, paper with two strokes; and, blind to the former, he would see all that was in the latter, because he would have apperceived it as a different total in the first instance.
A process of this sort occurs sometimes (not always) when the new strokes, instead of Being mere repetitions of the original one, are lines which combine with it into a total effect, say a human face.The subject of the trance then may regain his sight of the line to which he had previously been blind, by seeing it as part of the face.
When by a prism before one eye a previously invisible line has been made visible to that eye, and the other eye is closed or screened , its closure makes no difference; the line still remains visible.But if then the prism is removed, the line will disappear even to the eye which a moment ago saw it, and both eyes will revert to their original blind state.
We have, then, to deal in these cases neither with a sensorial anæsthesia, nor with a mere failure to notice, but with something much more complex;
namely, an active counting out and positive exclusion of certain objects.
It is as when one 'cuts' an acquaintance, 'ignores' a claim, or 'refuses to be influenced' by a consideration of whose existence one remains aware.
Thus a lover of Nature in America finds himself able to overlook and ignore entirely the board- and rail-fences and general roadside raggedness, and revel in the beauty and picturesqueness of the other elements of the landscape, whilst to a newly- arrived European the fences are so aggressively present as to spoil enjoyment.
Messrs.Gurney, Janet, and Binet have shown that the ignored elements are preserved in a split-off portion of the subjects' consciousness which can be tapped in certain ways, and made to give an account of itself (see Vol.I.p.209).
Hyperæsthesia of the senses is as common a symptom as anæsthesia.
On the skin two points can be discriminated at less than the normal distance.
The sense of touch is so delicate that (as M.Delboeuf informs me) a subject after simply poising on her finger-tips a blank card drawn from a pack of similar ones can pick it out from the pack again by its 'weight.' We approach here the line where, to many persons, it seems as if something more than the ordinary senses, however sharpened, were required in explanation.
I have seen a coin from the operator's pocket repeatedly picked out by the subject from a heap of twenty others, by its greater 'weight' in the subject's language.-- auditory hyperæsthesia may enable a subject to hear a watch tick, or his operator speak, in a distant room.-- One of the most extraordinary examples of visual hyperæsthesia is that reported by Bergson, in which a subject who seemed to be reading through the back of a book held and looked at by the operator, was really proved to be reading the image of the page reflected on the latter's cornea.The same subject was able to discriminate with the naked eye details in a microscopic preparation.Such cases of 'hyperæsthesia of vision' as that reported by Taguet and Sauvaire, where subjects could see things mirrored by non-reflecting bodies, or through opaque pasteboard, would seem rather to belong to 'psychical research' than to the present category.-- The ordinary test of visual hyperacuteness in hypnotism is the favorite trick of giving a subject the hallucination of a picture on a blank sheet of card-board, and then mixing the latter with a lot of other similar sheets.The subject will always find the picture on the original sheet again, and recognize infallibly if it has been turned over, or upside down, although the bystanders have to re-sort to artifice to identify it again.The Subject notes peculiarities on the card, too small for waking observation to detect. If it be said that the spectators guide him by their manner, their breathing, etc., that is only another proof of his hyperæsthesia; for he undoubtedly is conscious of subtler personal indications (of his operator's mental states especially) than he could notice in his waking state.Examples of this are found in the so-called 'magnetic rapport.' This is a name for the fact that in deep trance, or in lighter trance whenever the suggestion is made, the subject is deaf and blind to everyone but the operator or those spectators to whom the latter expressly awakens his senses.The most violent appeals from anyone else are for him as if non-existent, whilst he obeys the faintest signals on the part of his hypnotizer.If in catalepsy, his limbs will retain their attitude only when the operator moves them;
when others move them they fall down, etc.A more remarkable fact still is that the patient will often answer anyone whom his operator touches, or at whom he even points his finger, in however concealed a manner.All which is rationally explicable by expectation and suggestion, if only it be farther admitted that his senses are acutely sharpened for all the operator's movements. He often shows great anxiety and restlessness if the latter is out of the room.A favorite experiment of Mr.E.Gurney's was to put the subject's hands through an opaque screen, and cause the operator to point at one finger.That finger presently grew insensible or rigid.
