Comparative Neurology and Psychology Volume XIV 1904 Number 4 THE ASSOCIATIVE PROCESSES OF THE GUINEA PIG. A STUDY OF THE PSYCHICAL DEVELOPMENT OF AN ANIMAL WITH A NERVOUS SYSTEM WELL MEDULLATED AT BIRTH. By JESSIE ALLEN. CONTENTS. INTRODUCTION. Review of literature. Problem of the work. 294 PART I. THE ASSOCIATIVE PROCESSES OF THE GUINEA PIG. 300 Test I. Is the mother a specific stimulus for her young? 306 Test XII. Efficiency of contact stimuli for following a path. 334 Conclusions from Tests X, XI and XII. 337 Summary of work with adult. 337 IV. The Development of the Guinea Pig Compared with that of the White Rat. 338 V'. The Psychic Life of the Guinea Pig Compared with that of the 339 PART II. THE CENTRAL NERVOUS SYSTEM OF THE GUINEA PIG. Introduction. 341 Cervical. Thoracic. Lumbar. 11. Development of the Medulla Spinalis from Birth to Maturity. Cervical. Lumbar. Summary of changes in medullation of the medulla spinalis. 1. Description of Transverse Sections Through the Medulla Spinalis 341 343 343 345 345 347 347 349 350 350 351 353 353 355 356 357 358 Development of the cerebral hemispheres. Cerebellum. Increase in the area of cross-sections of the encephalon. IV. Comparison Between the Nervous System of the Guinea Pig and that of the White Rat. INTRODUCTION. In the study of animal psychology the attempt is made to understand in their simplest manifestations the psychical factors entering into reactions to stimuli. With this in view reactions of all grades of intelligence have been investigated. Two different points of view have given opposing interpretations of the phenomena manifested by the lower animals. 1 M. BINET has observed the reactions of Paramecia to acids and alkalis, and has concluded that an action of adaptation involves spatial perception of the external object, choice between objects and movements of approach or avoidance. On the other hand, JENNINGS3 gives a physio-chemical explanation of these same reactions. All the movements of approach and retreat are automatically performed without regard to the "pleasure" or "pain" involved. The mechanism of the BINET. Psychic Life of Micro-organisms. Transl., Chicago, Open Court Pub. Co., 1889. 2 P. 61. 3 H. S. JENNINGS and E. M. MOORE. Studies on Reactions to Stimuli in Unicellular Organisms, VIII. Amer. Jour. Physiol., Vol. VI, 1902. movements is put into play by the physical or chemical properties of the medium. The insects exhibit a comparatively complex organization. LUBBOCK and ROMANES attribute a high degree of psychical development to bees, wasps, spiders and ants. Dr. and Mrs. PECKHAM are more conservative, but conclude that there are present memory, spatial perception, and occasional adaptations of means to end. ALBRECHT BETHE1 represents the extreme mechanical interpretation of insect activities, believing them to be expressible in terms of immediate sensory stimuli followed by the motor response. BETHE'S principal opponent is AUGUST FOREL,' whose recent work on the ants leads him to conclude "that sensation, perception and association, inference, memory and habit follow in the social insects on the whole the same fundamental laws as in the vertebrates and ourselves. Furthermore, attention is surprisingly developed in insects." These faculties are, however, manifested in a feeble form. LOEB is inclined to attribute a small amount of intelligence to ants. The question here is whether these animals do or do not have any psychical life. The criterion of intelligence now generally used in experimental work with lower animals is that of educability. LOEB' discusses the distribution of the associative processes among the lower animals. When his book was published only tree frogs, among frogs, were known to possess memory. 5 YERKES, in an extended series of careful experiments, finds that the green frog has associative processes, but that as 1 BETHE. Dürfen wir den Ameisen und Bienen psychische Qualitäten zuschreiben? Arch. f. d. ges. Physiologie (PFLÜGER'S), LXX, p. 15, 1898. 2 FOREL. Ants and Some Other Insects. (Translated by W. M. WHEELER.) Monist, Vol. XIV, pp. 33-66, 177-193, 1903-1904. 3 LOEB. Comparative Physiology of the Brain, 1902, p. 224. Loc. cit., pp. 219, f. 5 YERKES. The Instincts, Habits and Reactions of the Frog. Harvard Psychological Studies, Vol. I, 1902. sociations are very slowly acquired. The sensory elements which enter into them are visual, tactual and kinesthetic. YERKES used a simple labyrinth, testing the frog's memory of a path to water; he kept records of time as well as of movements made. A straight path was learned by a process of selection from random movements of those which led to the desired object. YERKES' Work on the crustaceans stands almost alone. The green crab and the crawfish both profit a little by experience and learn simple labyrinth paths. BETHE had shown that Carcinus maenas could not readily learn to inhibit deep-seated instincts.2 SPAULDING 3 finds that hermit crabs profit by experience with considerable rapidity when visual and taste sensations may be associated. Upon comparing the fish, the frog and the turtle' YERKES found that the turtle's associations were formed most rapidly, a somewhat complex path being learned in five trials. Very little other experimental work has been attempted with animals of this grade. TRIPLETT' found that perches can remember a glass partition which has been removed from the aquarium. He verified the possibility of teaching pikes to inhibit their habit of devouring minnows (MOEBIUS' experiment). DELBOEUF has observed lizards in captivity and finds that they differ in disposition and intelligence. They can remember people and places, and they seem to possess the higher emotions as fear,.love, jealousy. R. M. YERKES and GURRY E. HUGGINS. Habit Formation in the Crawfish. Harvard Psychological Studies, Vol. I, 1902. YERKES. Habit Formation in the Green Crab, Carcinus granulatus. Biological Bulletin, Vol. III, 1902. 2 BETHE. Das Centralnervensystem von Carcinus maenas. II Theil, Arch. f. mikr. Anat., Bd. LI, p. 447. 3 E. G. SPAULDING. Association in Hermit Crabs. Jour. Comp. Neurol. and Psychol., Vol. XIV, p. 49, 1904. 1901. YERKES. Formation of Habits in the Turtle. Pop. Sci. Mo., LVIII, p. 519, 5 TRIPLETT. The Educability of the Perch. Amer. Jour. Psychol., Vol. XII, p. 354, 1901. 6 DELBOEUF. The Affections and Jealousies of Lizards. Pop. Sci. Mo., Vol. L, 1897 and Revue Scientifique, Vol. IV, pp. 363-367, 690 and 805. |