An investigation into the functions of the occipital and temporal lobes of the monkey's brain / by Sanger Brown and E.A. Schäfer.

  • Sanger Brown
Date:
1888
Catalogue details

Licence: Public Domain Mark

Credit: An investigation into the functions of the occipital and temporal lobes of the monkey's brain / by Sanger Brown and E.A. Schäfer. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    visual perceptions. There was no loss of movement of the eyeball or eyelid, nor any anaesthesia of the cornea. Second Operation.—Was performed eight days after the first, and consisted in the destruction of the remaining angular gyrus in the same manner. Tested in less than an hour after the operation, shows no impairment of vision, nor of the motion of the eyeballs or lids, nor was the cornea of either eye rendered anaesthetic, or even, so far as could be determined, diminished in sensibility. The animal was kept for a month without further operation, during which time it was frequently tested, but always with negative results. Third Operation.—A month after the last. This operation was intended to effect the destruction of the superior temporal gyri on both sides, the greater part being cut away with the knife, and the destruction of the remainder right up to the bounding fissures being completed by the actual cautery. It was found, however, on post-mortem examination, that on the right side the second temporal gyrus had been mistaken for the first, and that the latter had remained almost intact. This mistake was not suspected during life, and the animal was always shown as one with both superior temporal gyri destroyed. Results.— The only noticeable symptom in this animal is an apparent stiffness of the neck, so that when she desires to rotate the head, the shoulders and upper part of the trunk move also. This appears to produce a certain amount of reluctance to turn towards sounds and objects which might attract the attention, and a consequent appearance of stupidity; but she nevertheless gives unmistakable signs that she hears acutely, and also that she is able to localise the direction of sounds. No other symptoms but the one mentioned—the appearance, namely, of stiffness of the neck— could be detected in this animal, although she was under daily observation for some months, and was frequently carefully tested with respect to all the special senses. About four months after the first operation, having been in very fair health during that time, the animal was seized with epileptiform convulsions, which continued without intermission for a number of hours and only ended with death. Autopsy: Condition of the Brain.—The superficial grey matter of both angular gyri is destroyed. The lesion also involves the posterior border of the external parieto-occipital fissure. On the left side the superior temporal gyrus is destroyed. On the right side this convolution remains, but the second temporal gyrus and the portion of the temporal lobe immediately below it are destroyed. The rest of the brain is healthy, with the exception of a small patch of yellow softening in the middle of the left ascending parietal gyrus. The brain is represented in Plate 49, figs. 5a, 56, and 5c. Remarks.—This experiment is of especial interest, firstly on account of the totally negative results, both immediate and remote, of decorticization of the angular gyri; secondly, by reason of the peculiar stiffness and immobility of the neck which followed the second operation; and thirdly, because it is the only one of our experi-
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