288 



SCIENCE. 



[Vol. XX. No. sy 



TliE INTERNATIONAL CONGRESS OF EXPERIMENTAL 

 PSYCHOLOGY, HELD IN LONDON, AUGUST, 1893. 



BT ARTHUB MACDONA.LD, SPECIALIST IN THE U. S. BUREAU OF EDU- 

 CATION, AND OFFICIAL DELEGATE TO THE CONGRESS. 



One of the distinguishing features of the late International 

 Congress for Psychology is the prominent part that phvsiological 

 investigations assumed. This may be taken as an iodication of 

 the prevalent tendency to study the objective rather than the 

 subjective side of consciousness. Yet not a few of the members 

 read papers, which gave the results of an empirical study of sub- 

 jective reality. The subject of hypnotism and allied states was 

 also one of great interest to all. 



Some of the most important questions considered were in the 

 domain of the physiology of the brain, about which compara- 

 tively little is known. The statement has often been made that 

 the frontal convolutions are the seat of the intellect as distin- 

 guished from the will and desire. This was based upon com- 

 parison in the development of this region in man and the lower 

 animals, upon results of accident or disease in man and experi- 

 ments upon monkeys by Ferrier, Horsley. and Schafer, and 

 upon dogs by Hitzig and Goltz. For the reason that antiseptic 

 precautions were not taken in either Ferrier's earlier experiments 

 «r Goltz's or Hitzig's, it isnot certain but that the results obtained 

 may have been due to an extension of the effects of the injury. 

 Professor Schafer thought it worth while to repeat these experi- 

 ments upon the prefrontal region by a mode of operation that en- 

 tu-ely avoided the shock following from a bilateral removal of a 

 more or less extensive part of the brain. He said that he had 

 often noticed in operating upon the brain that extensive bilateral 

 lesions are liable to be followed by apathy and apparent idiocy, 

 whether the operations were in the frontal or in other regions, 

 more in fact in the temporal than in the frontal region. He 

 Ihinks it is very probable, therefore, that (1) the question of shock 

 and (2) that of considerable loss of brain substance and removal 

 of support from the rest of the brain (thus impairing the cerebral 

 functions generally) may modify the result. For these reasons 

 Professor Schafer has recently operated, not by actually remov- 

 ing the portions of the brain, but by severing their connections 

 with the rest of the mantle and with the brain-stem. This can 

 he effected with scarcely any hemorrhage and with no perceptible 

 shock. In several instances in which Professor Schafer has 

 thus severed the prefrontal lobes in monkeys, there was an entire 

 want of appreciable symptoms. In no case did the animals show 

 the dullness and apathy previously noticed, but they appeared as 

 bright and intelligent after recovering from the effects of the 

 anaesthetic as before the operation. These experiments, there- 

 fore, do not support the view that the prefrontal lobes are espe- 

 cially the seat of intelligent attention. 



In this connection it will be interesting to note Professor 

 Horsley's demonstration of localization of functions in the mon- 

 key 's brain, which was given before a number of specialists and 

 psycho-physicists. The monkey was put under the influence of 

 an anaesthetic, and quite a portion of the cranium removed. By 

 electric stimulation Professor Horsley demonstrated clearly the 

 fact of localization; he was able to predict before applying the 

 electrodes what movements would take place, as in the arm, fin- 

 gers, and face. The experiment was very satisfactory to the 

 witnesses, although Professor Horsley did not think it had suc- 

 ceeded as well as in many former cases when he had performed 

 St before his classes. These now well-known localized areas in 

 the brain of monkeys have been found also by Horsley and 

 Schafer in the anthropoid ape, which is still nearer man. But 

 the proof has been made complete in a demonstration upon human 

 beings by Professor Horsley. It was in the case of two epileptics 

 in whom an operation was necessary. As far as the operation 

 permitted, it was found that the same localization of function 

 existed in man. It is well to note that the success of experi- 

 ments upon animals is often due to developed operative skill, as 

 is obtained in surgery. The writer has witnessed many opera- 

 tions of this nature by well-known specialists, but has never seen 

 it so neatly done as by Professor Horsley. Professor Horsley 



was also very careful to see that the animal felt no pain through- 

 out the whole operation. One is reminder! of Professor Munk's 

 experiments on the dog at Berlin, which attracted great attention 

 at the time. Both Munk and Horsley are surgeons 



It is true that, if one single function is localized, brain localiza- 

 tion is established ; but this a priori method is being made less 

 and less necessary by experimentation. It would seem from these 

 and other investigations that the intellectual function is diffused 

 over the whole brain; this is strengthened by purely psychologi- 

 cal considerations from the directing power of the reasoning fac- 

 ulty over the psychical functions in general. It would seem 

 probable that by moreexact methods and skilful operations general 

 localized areas will be established throughout the brain, but that 

 these areas can be absolutely defined is quite improbable; first, 

 because they seem gradually to overreach, one area into the other, 

 and, second, the brain is a vicarious organ and the extent of this 

 characteristic will be difficult to determine. But when one 

 thinks of the complexity of the finer anatomy of the brain, not 

 to mention its histo-physiology and chemism, the vastness of the 

 field of investigation is evident; yet these positive results in the 

 coarser anatomy and physiology are an initial starting-point of 

 the highest importance, and may lead in the future to things as 

 yet unthought of. 



A recent experiment illustrating kinsesthesis was described by 

 Dr. Ransom; it was a case of epilepsy where the convulsions be- 

 gan by tingling and spasm in the left hand ; the following perma- 

 nent abnormal conditions resulted in this hand: (1) Slight tactile 

 ansBsthesia, (3) diminution of muscular sense, (3) diminution of 

 motor power. The operation showed a cyst compressing the 

 cortical centre for the left hand. After recovery from the opera- 

 tion this area was faradized by electrodes inserted through the 

 scalp, without an anEesthetic. From this resulted (1) contraction 

 of groups of muscles in arm and hand by moderate current, (3) 

 production of sensation with a weaker current, contraction added 

 when current was strengthened, (3) improvement of muscular 

 sense during and after stimulation, (4) weakening of voluntary 

 motor power, after a strongly induced contraction. 



Dr. H. Donaldson, in his observations on the anatomy of the 

 brain of Laura Bridgman, found the following peculiarities: de- 

 pression of the moter speech-centre, a slenderness of the first tem- 

 poral gyrus on both sides and a blunting of both occipital poles 

 with a special disturbance of the fissures in the right cuneus, 

 poor development of temporal lobes, the cranial nerves connected 

 with the defective sense organs were slender, the left optic nerve 

 being the one most affected; the extent of cortex was normal 

 but unduly thin all over; this thinness, however, was most 

 marked in the areas for the defective senses, due in part at least 

 to the smallness of the cortical c,ells there present. In general, 

 the case represents a maximum peripheral disturbance in the sen- 

 sory cranial nerves, associated with only such central lesions as 

 followed from lack of exercise and growth. 



In his investigations of the muscular sense in the blind, Dr. 

 Goldscheider found a developed sense of touch in the hand and 

 finger joints, and the cause of this was psychical, consisting in a 

 sharpening of the attention and in practice. The sense of loca- 

 tion in the skin is small in the blind. In order to recognize 

 forms by touch, the sensation of motion is of greater importance 

 than the sensibility of the skin. Children, whether blind or not, 

 possess a finer sensibility for passive motion than adults. 



An interesting paper was that on " A Law of Perception,'' by 

 Professor Lange of Odessa. The process of every perception con- 

 sists in a rapid change of a whole series of psychical moments or 

 steps, in which every preceding step presents a less concrete and 

 more general condition, and every following step a more concrete 

 and differentiated psychical condition. There are four principal 

 steps, or stages, in this process of perception: (1) the simple 

 shock, without quality, (3j the consciousness of general modality 

 in the sensibility, (3) consciousness of its specific quality, and (4) 

 consciousness of its spacial form. 



The steps, or stages, of our perception correspond to the devel- 

 opment of perception in general biological evolution. The so- 

 called muscular reactian consists in a reaction in consciousness 

 upon a simple and undifferentiated shock; the muscular or the in- 



