Any modification of attention is of course likely to be at once a check and a stimulus;—a check to certain thoughts and emotions, a stimulus to others. And in many cases it will be the dynamogenic aspect of the change—the new vigour supplied in needed directions—which will be for us of greatest interest. Yet from the inhibitive side also we have already had important achievements to record. All these arrests and destructions of idées fixes, of which so much has been said, were powerful modifications of attention, although the limited field which they covered made it simpler to introduce them under a separate heading.
And even now it may not be without surprise that the reader finds described under the heading of inhibition of attention a phenomenon so considerable and so apparently independent as hypnotic suppression of pain. This induced analgesia has from the first been one of the main triumphs of mesmerism or hypnotism. All have heard that mesmerism will stop headaches;—that you can have a tooth out "under mesmerism" without feeling it. The rivalry between mesmerism and ether, as anæsthetic agents in capital operations, was a conspicuous fact in the medical history of early Victorian times. But the ordinary talk, at any rate of that day, seemed to assume that if mesmerism produced an effect at all it was an effect resembling that produced by narcotics—a modification of the intimate structure of the nerve or of the brain which rendered them for the time incapable of transmitting or of feeling painful sensations. The state of a man's nervous system, in fact, when he is poisoned by chloroform, or stunned by a blow, or almost frozen to death, or nearly drowned, etc., is such that a great part of it is no longer fit for its usual work,—is no longer capable of those prolongations of neurons, or whatever they be, which constitute its specific nervous activity. We thus get rid of pain by getting rid for the time of a great deal of other nervous action as well; and we have to take care lest by pushing the experiment too far we get rid of life into the bargain. But on the other hand, a man's nervous system, when hypnotic suggestion has rendered him incapable of pain, is quite as active and vigorous as ever,—quite as capable of transmitting and feeling pain,—although capable also of inhibiting it altogether. In a word, the hypnotic subject is above instead of below pain.
To understand this apparent paradox we must remind ourselves that pain probably originated as a warning of danger,—a warning which, while useful to active creatures with miscellaneous risks, has become only a mixed advantage to beings of more advanced intelligence and sensitivity. There are many occasions when, knowing it to be useless, we wish to shut off pain, to rise as definitely above it as our earliest ancestors were below it, or as the drunken or narcotised man is below it. This is just what hypnotic suggestion enables us to do.
Hypnotism attacks the real origo mali;—not, indeed, the pressure on the tooth-nerve, which can only be removed by extraction, but the representative power of the central sensorium which converts that pressure for us into pain. It diverts attention from the pain, as the excitement of battle might do; but diverts it without any competing excitement whatever. To this topic of influence on attention we shall have to recur again and again. For the present it may suffice if I refer the reader to a few cases—chosen from among some thousands where hypnotic practice has removed or obviated the distress or anguish till now unmistakably associated with various bodily incidents—from the extraction of a tooth to the great pain and peril of childbirth.[72]
This suppression of pain has naturally been treated from the therapeutic point of view, as an end in itself; and neither physician nor patient has been inclined to inquire exactly what has occurred;—what physiological or psychological condition has underlain this great subjective relief. Yet in the eye of experimental psychology the matter is far from a simple one. We are bound to ask what has been altered. Has there been a total ablation, or some mere translation of pain? What objective change on the bodily side has occurred in nerve or tissue? and, on the mental side, how far does the change in consciousness extend? How deep does it go? Does any subliminal knowledge of the pain persist?
The very imperfect answers which can at present be given to these questions may, at any rate, suggest directions for further inquiry.
(1) In the first place, it seems clear that when pain is inhibited in any but the most simple cases, a certain group of changes is produced whose nexus is psychological rather than physiological. That is to say, one suggestion seems to relieve at once all the symptoms which form one idea of pain or distress in the patient's mind; while another suggestion is often needed to remove some remaining symptom, which the patient regards as a different trouble altogether. The suggestion thus differs both from a specific remedy, which might relieve a specific symptom, and from a general narcotisation, which would relieve all symptoms equally. In making suggestions, moreover, the hypnotiser finds that he has to consider and meet the patient's own subjective feelings, describing the intended relief as the patient wishes it to be described, and not attempting technical language which the patient could not follow. In a word, it is plain that in this class, as in other classes of suggestion, we are addressing ourselves to a mind, an intelligence, which can of itself select and combine, and not merely to a tissue or a gland responsive in a merely automatic way.
(2) It will not then surprise us if,—pain being thus treated as a psychological entity,—there shall prove to be a certain psychological complexity in the response to analgesic suggestion.
By this I mean that there are occasional indications that some memory of the pain, say, of an operation has persisted in some stratum of the personality;—thus apparently indicating that there was somewhere an actual consciousness of the pain when the operation was performed.[73] We find accounts of the revival of pain in dreams after operations performed under chloroform.[74]
(3) Such experiences, if more frequent, might tempt us to suppose that the pain is not wholly abrogated, but merely translated to some stratum of consciousness whose experiences do not enter into our habitual chain of memories. Yet we possess (strangely enough) what seems direct evidence that the profoundest organic substratum of our being is by suggestion wholly freed from pain. It had long been observed that recoveries from operations performed in hypnotic trance were unusually benign;—there being less tendency to inflammation than when the patient had felt the knife. The same observation—perhaps in a less marked degree—has since been made as to operations under chemical anæsthesia. The shock to the system, and the irritation to the special parts affected, are greatly diminished by chloroform. And more recently Professor Delbœuf, by an experiment of great delicacy on two symmetrical wounds, of which one was rendered painless by suggestion, has distinctly demonstrated that pain tends to induce and keep up inflammation.[75]