DUAL CONSCIOUSNESS.
IIGOOD deal of bewilderment and almost of conster- nation has been aroused in those who have studied some of the recent cases of French hysteria by the apparent change of character which takes place between different nervous conditions of the same individual, — cases, for example, in which a change of the paralysis from one side of the brain to the other, appears to effect a change from a sober, patient, and industrious woman, to a violent, disreputable, and lazy person imprisoned in the same body. We very much doubt whether this is the true reading of any of these cases. For there can be no doubt that the change from the activity of certain powers and certain desires to that of a quite new set of powers and desires might effect a very great apparent change in the character without effecting a real change in it; and there is every reason to believe that this is what the change from the activity of one side of the brain to the other, when they are not used in co-ordination, really effects. It is more or less like the change which the loss of interests and active occupations in old age often effects, or like the change which growth from infancy to maturity in children whose hearts have never been really touched by their parents and teachers, often effects, though the true character may have undergone very little real change at all. In the quarterly journal of the Neurological Society, called Brain, just issued, there is a curious and interesting paper by Mr. Lewis C. Bruce, late Assistant Medical Officer to the Derby Borough Lunatic Asylum, on a case he had carefully studied while at that insti- tution. The peculiarity of the case was this—that it appeared to show that while some general deterioration of the brain was going on, it was going on at a different rate in the two lobes of the brain ; that sometimes the right side of the brain alone acted, in which case the patient talked almost only Welsh, and had hardly any interest in life at all, showing no sort of eagerness either for money or tobacco, or anything but his food alone, and that he was almost entirely left-handed and idiotic; while when that aide of the brain became inert, and the other took its place, he spoke chiefly English, was eager for money and tobacco, and even thievish in his desire to possess himself of these objects, and right-handed in his physical habits; and that for a certain interval between the two conditions he had a short period in which he mingled Welsh and English words, used both hands, and showed an interme- diate sort of disposition, being more alive than in his lef t- handed condition, when he spoke Welsh almost exclusively, and, we imagine, less alive than in his right-handed condition, when he spoke chiefly English. The suggestion of the paper is, we gather, that in the more deteriorated or Welsh stage, he had lost all command of the acquisitions of the most active part of his life, and retained only a trace of those which were most automatic and deeply imbedded in his habits, being very nearly an idiot; while in his English stage, though restless and maniacal, he had still some eager desires left, was far more excitable, far keener to enjoy the few pleasures which were then still open to him, and kept some feeble command over the powers which, at the brightest period of his life, he had possessed. Specimens of his writing are given in both stages; and while his Welsh writing is almost wholly illegible, and appears to go from right to left, like the reversed image of writing as seen in a mirror, the English writing is more legible, goes from left to right, and is in every way more normal. In his Welsh state he was so inert that he sat crouched together, and could hardly be induced to make any effort at all. In his English stage, when he used his right hand and the left side of his brain was at work, though thievish, he was good- humoured, and keen to get money or tobacco by any means in his power. In short, it seemed as if the little trace of mind he had left, almost all belonged to the time when the left side of his brain was at work, and hardly any of it to the Welsh or right lobe of the brain. The disease had begun apparently in the lobe which is less closely connected with mental associations, and had proceeded farthest there. It had attacked, but not proceeded so far in, the lobe which is most closely connected with the effort to think and speak, and write, and wish. What may be called the more animal brain was going first, and the more intellectual brain was slowly following. For very short intervals, there was a period when both sides of the brain still seemed to work together ; but there seems to have been no evidence that in that very temporary stage, he was more intelligent than in his English stage only. But these intervals were so brief, so merely transition stages, that there was hardly any fair opportunity of testing their character. Mr. Bruce seems to think, though he does not give us his
grounds for thinking, that even in health, Hugh Parry,—that was his name,—had used the two sides of his brain inde- pendently, and not in co-ordination, not as the eyes are used in binocular vision. Even if both were used together, they would, he thinks, be used simultaneously, but not so as to help each other in a common effort. And when disease set in they began to be used alternately with very brief intervals of simultaneous activity.
The interest of this case is that it appears to suggest that the two sides of the brain are like the two eyes and two ears, modes of communication with the external world of the same kind, but often of very different degrees of power. Hugh Parry had far keener senses when he used the left side of his bran than he had when he used the right. He then distinguished sweet from bitter, pleasant smells from unpleasant, and one colour from another, while when he used the right side of his brain only he could not distinguish colours at all, though he could feel the difference between hard and soft, and the dif- ference between hot and cold. In fact, he had access to the secondary qualities as they are called with the left side of his brain as well as to the primary, and chiefly to the primary with his right ; but the right, though it was much more diseased than the left, had evidently taught him the same kind of things as the other, and had been used, for instance, in learning to speak and write Welsh, though it had lost more by deterioration. He was more crippled on the right side of his brain than on the left ; but though organs of unequal force, they were organs of the same kind. It would not be true to say that he either thought or remembered or even felt with one side only, and not with the other side ; he used the two sides of his brain, like a man with two eyes of unequal visual power which he cannot bring to the same focus. He got a very different amount of experience from the two sides of his brain, but not experience of a totally different kind, except so far as disease had made greater progress in one lobe than in the other.
What the case appears to us to show is that the two sides of the brain may be, or may become, two very different instruments for connecting us with the external world, and for giving information, and providing us with objects of desire in that world ; and that one of the two lobes of the brain provides us a good deal more of access to the external world of thoughts and things and external objects of desire than the other. Indeed, they resemble two instruments of very different power, which, when they are in harmony, are stronger and more powerful than either taken alone ; but if they happen to act separately, are of very different calibre and efficiency. Now it seems to us that, in this case at least, and probably in most of the other cases, the difference between the action of the two lobes of the brain in cases of mental disease is this, that the more powerful instrument, the left lobe, opens a much wider field of experience to the action of the character and will than the right lobe, and therefore opens the mind to a larger field of desires, being an instrument of much greater power for gratifying those desires, and presenting therefore a much more considerable field both of temptation and of motive for resisting temptation, than the other. Whenever, there- fore, they do not act together, the true motives and character of the man is much better determined by what he is and does when the left lobe of the brain is in order, than by what he is and does when only the right lobe is in order. In the present case neither was in order, but the more powerful instrument was not quite so much crippled as the less power- ful, and consequently, so far as you could judge of the man's character at all, the English stage was more of an index to his habitual tone of mind, than the Welsh stage which hardly opened to him any field of action at all, just as a man with one eye nearly blind and the other only rather dim, would see much less when he used the blind eye only, than he would when he used the other which was only a little dim. But it would be a mistake to infer that the man's character was totally different in the one case from what it was in the other. It would be true that the will and character had fuller play when it had the use of the least crippled organ, than it had when it used the most crippled organ, but it would not be true to infer that the personality behind the brain was different in kind. And in other cases we suspect it might be shown that though there might be much more steadiness and sobriety of action, and much more reasonableness and good husaour when the more powerful organ was in use, than there was in the converse case, there would be pretty much the same kind of moral judgment in both cases. There is a Jekyll and a Hyde in many men, and it is quite possible that the Hyde might be kept in better order and more completely controlled with the aid of the more effective side of the brain than it would be without that aid. But for the most part the difference would be that the same man sought the same things with his true nature, but had less control over himself in the one case than he had in the other. We do not believe in two different men inhabiting the same body, but rather in one and the same man being subjected to a different class of temptations, and commanding a different class of powers in the one case and in the other. Ha gh Parry is even a poorer creature when he has only the right lobe of the brain at work than he is when he has the left ; he has more animal desires and more intelligence as to the best mode of satisfying them, so that he might seem to be a worse man, with the left side of his brain at work than he is with the right. Bat in all probability it is the difference only between the larger and the smaller field of temptation and opportunity which gives this appearance. In other cases the more powerful side of the brain would on the other hand often strengthen the better class of habits rather than the worse, by securing attention to the conventional conditions which impose a certain decency, sobriety, and respect for public opinion, a field of motive far beyond poor Hugh Parry's reach in either state of his diseased brain. But we do not believe that any of these cases fully examined would prove that the patient had a really double character, bat only much more defective means of communicating with the world in one state than in the other, and therefore a different set of desires, memories, and powers. So it is often with the very young and very old. You see, both in childhood and in old age, what the true bias of the will is, better perhaps than in youth and the full activity of worldly cares. In the storms of youth and middle life the complexities of motive are so great that you can with difficulty determine what is due to the true character of the man and what only to the accident of opportunity and the balance of conflicting in- clinations.
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