Open Access

JSON Export

{"created":"2022-01-31T15:21:11.590662+00:00","id":"lit28740","links":{},"metadata":{"alternative":"Studies from the Yale Psychological Laboratory","contributors":[{"name":"Rice, James F.","role":"author"}],"detailsRefDisplay":"Studies from the Yale Psychological Laboratory 5: 81-87","fulltext":[{"file":"p0081.txt","language":"en","ocr_en":"THE SIZE-WEIGHT ILLUSION AMONG THE BLIND.\nBY\nJames F. Rice, M.A.\nIt is a well known fact that when two objects of equal weight but different size are lifted, the smaller appears heavier than the larger. The phenomenon has been made the subject of experiment in various ways.1\nIt was suggested to me that some experiments on the blind might be of interest. The experiments were performed at the New York Institution for the Blind. They were carried out under the direction of the Yale laboratory with the suggestion-blocks formerly used by Dr. Seashore. Many suggestions in regard to the details of the experiments were received from Dr. Seashore personally.\nApparatus.\nThe apparatus consisted of two sets of cylindrical blocks 31\u201c\u2019\u201c in length. Each set consisted of 17 blocks. Set A varied in size and had a uniform weight, while Set B varied in weight and had a uniform size. The blocks in Set A varied in diameter according to a geometric series in which the regular increment is one-tenth. Those in Set B were arranged in arithmetic series according to weight with a successive difference of 5g.\nIn the following account the blocks will be dintisguished by the names A and B with their respective numbers in the series.\n\u25a0Fkchner, Usher die Contrastempfilulling, Ber. d. k.-s\u00e4chs. Ges. d. Wiss., math, phys. Cl., 1S60 XII 76.\nMueller and Schumann, Uebcr die psychologischen Grundlagen der Vergleichung gehobener Gewichte, Archiv, f. d. ges. Physiol. ( l\u2019fl\u00fcger), 18S9 XLV 37.\nCharpentier, Analyse de quelques \u00e9l\u00e9ments de la sensation de poids, Archives de Physiol., 1891 (5) III 122.\nDresslar, Studies in the psychology of touch, Am. Jour. Psych., 1894 VI 313.\nFLOURNOY, De /\u2019 influence de la perception visuelle des corps sur leur poids apparent, L\u2019Ann\u00e9e Psychol., 1S94 I 198.\nGilbert, Researches on the mental and physical development of school-children, Stud. Yale Psych. Lab., 1S94 II 43-45, 59-63.\nPhilippe and Claviere, Sur une illusion musculaire, Revue Philos., 1S94 XL 674.\nVan Biervi.iet, La mesure des illusions de poids, L\u2019Ann\u00e9e Psychol., 1895 II 79.\nGripping, On the sensations of pressure and impact, Psychol. Rev., 1895 II Suppl. I.\nScripture, Remarks on Dr. Gilbert's article, Stud. Vale Psych. Lab., 1894 II 102.\n6\t81","page":81},{"file":"p0082.txt","language":"en","ocr_en":"82\nJames F. Rice,\nThe blocks of Set A were of a constant weight, 80% and of diameters in millimeters as follows, beginning with the smallest : 20.0, 22.0, 24.2,\n26.6,\t29.3, 32.2, 35.4, 39.0, 42.9, 47.2, 51.9. 57.1, 62.8, 69.1, 76.0,\n83.6,\t91.9.\nPig. 24.\n\u2019\nThe blocks of Set B were of a constant diameter, 42.9\"\"\", and of weights in grams as follows, beginning with the lightest : 40, 45, 50, 55> 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, no, 115, 120.\nIt is to be observed that the uniform weight for Set A is the same as the weight of B (9), the middle block in Set B ; and the uniform size in Set B is the size of A (9), the middle block in Set A.\u2019\nThe observer placed himself by the table, on which the blocks were arranged in order, in such a position that by moving back and forth he could lift any block from its place in Set B and still retain approximately the same angle of the arm and hand. He was requested to select for each block in Set A a corresponding one in Set B, by taking one at a time from A and placing it by the side of successive blocks in B with which he wished to compare it, lifting one at a time until he found the one in B which he thought had the same weight as the one from A.\nOne series of tests D was made in which the size of the weights was learned by grasping the curved surface of the block ; a second series of tests E was so made that the observer could only judge of the size from\n\u25a0Seashore, as before; Scripture, New Psychology, Pig. 65, London 1897.","page":82},{"file":"p0083.txt","language":"en","ocr_en":"Size-ivcight illusion among the blind.\n83\n1\nthe area of pressure when the block was placed gently upon the palm of his hand. All the A blocks were used in each series. Each series of tests was made ten times, and, to eliminate as far as possible the error of prejudice, the equivalent B for each A block was approached five times from above, five times from below. That is, in five of each series an A block was compared first with a B that was very perceptibly heavier and then with the B of next lower weight until apparent equality was reached. In the other five the steps were from the perceptibly lighter.\nFig. 25.\nTo eliminate the error of sequence, the observer lifted the blocks in the orders A, B, B, A, and B, A, A, B alternately. The position of the blocks was reversed after each trial, so that the observer\u2019s judgment was not affected by the varying sensations caused by the slight movement ot the forearm to the right or left. By this exchange of position there was also to a slight extent avoided the fixing of the observer\u2019s attention upon the A with which the several 7>\u2019s were being compared ; his judgment was, without explicit reference to either block as a standard, merely a judgment of equality. In case of a perceived difference he indicated which was the heavier.\nSubjects.\nIt is desirable for experiments on the psychology of the blind that the subject should have been totally blind from birth. It has been held, in-","page":83},{"file":"p0084.txt","language":"en","ocr_en":"\u00bb\n84\tJames F. Rice,\ndeed, that with the congenitally blind we should class as competent observers those who became blind during their first year,1 and many who have studied the blind have included in their observations those who had lost their sight as late as the seventh year.2 Obviously the mental life of those whose experience includes light sensations cannot be identical with that of those totally blind from birth. The assumption that the conditions are similar cannot be established until the psychology of the congenitally blind, who have never seen light, has been first studied. The subjects in the experiments here described have been blind from birth and have never seen light.\nM is a college graduate and university professor ; he is a mathematician of international reputation. O, his brother, is in business in New York. They are both graduates of the New York Institution for the Blind.\nFig. 26.\nMwas from the start quite aware of the illusion, and though he was kept in ignorance of the purpose of the tests, he repeatedly spoke of the impossibility of correct estimates of weight when the objects compared were of different sizes. It was his opinion that of the two tests the second, i. e., with the weights on the palm of the hand, was the least accurate. His custom had always been to compare weights by grasping in quick\n\u25a0Hki.LER, Studien zur Blindai-Psychologie, Fhil. Stud., 1895 XI 252.\n2 Hocheisen, (Jeher den Muskclsin hei Blinden, Zt. f. Psych, u. Phys. d. Sinn., 1893 V 239.","page":84},{"file":"p0085.txt","language":"en","ocr_en":"Size-weight illusion among the blind.\n35\nsuccession the objects to be judged, and dropping them, if small, from one hand to the other, or by weighing them upon the tips of the fingers, as in the case of coins. In the methods of these experiments he had no previous experience.\nO was also fully aware of the illusion. He, like M, considered the third series of judgments the least satisfactory, and expressed the same\npreference for grasping rather than mere lifting upon the palm. O thought that size was less diverting in the first series than in the second.\nExperiments.\n(1) The first series of tests was that in which the knowledge of size was gained through the muscle sense, corresponding to Seashore\u2019s \u201c fourth series, H, muscle sense.\u201d An A and a B block, resting on end upon a soft pad, were lifted in succession, being grasped around the circumference by the thumb and middle finger of the right hand. If the weights were judged unequal, the B was replaced by another of the same set. Because the observer did not have to make any choice of B\u2019s, but to consider only two blocks at a time (selected by the one conducting the experiment), he could fix his attention upon the question of equality of weight undistracted by the knowledge of the number of blocks that might possibly be compared.\n( 2 ) In another set of experiments the block was laid on the palm of","page":85},{"file":"p0086.txt","language":"en","ocr_en":"86\tJames F. Rice,\nhand ; this gave an idea of the size, the height being known to be constant. This corresponds to Seashore\u2019s \u201c fourth series, I, touch.\u201d\nFic. 28.\nIllusion or \u00bbeicht from oirpewi\u00bb\u00bb SENSES\nSize estimated by H. MUSCLE SENSE I .TOUCH J, SICHT\nD. MUSCLE SENSE TOUCH \u00bb SICHT\nFig. 29.\n","page":86},{"file":"p0087.txt","language":"en","ocr_en":"Size-weight illusion among the blind.\n87\nThe results are given in the table. Each result in the columns D, and Du is the average of 5 original measurements ; the probable error for these results never exceeds 4% and is generally less than 2%. The results in the table are indicated graphically in Figures 24, 25, 26, 27. Figure 28 shows the average results for both observers together with the curve H of Dr. Seashore\u2019s experiments.\nc\tDi\tD\u201e\tD\t\tM Ei\t\tE\u201e\t\tE\t\tD,\t\tD\u201e\t\t0 D E,\t\t\u25a0E11\t\tE\n\u2014 22.9\t+9\t+ 22\tT\u201c\tl6\t+\tS\t+ 16\t\t+ 11\t\t+ X2\t\tH\tb 34\t+ 23\t\u2014 4\tH\th 37\t+ 17\n\u2014 20.9\t+ 5\t4- 26\t+16\t\t-1-\t6\t+ \u00ab4\t\t+ 10\t\t+ *3\t\t-\t-30\t+ 22\t\t 2\t\t-31\t+ 15\n-18.7\t-f7\t+ 16\t+ 12\t\t+\t3\t-f-\t14\t-1-\t9\t-\t- 9\t-\t-29\t+ 19\t+ 2\t\t-27\t+ 15\n\u2014 16.3\t+ 5\t4- 9\t+\t7\t+\tI\t-j-\t14\t-j-\t8\t\t- S\t-\t-25\t+ 15\t\u2014 4\t\t\u201c35\t4-16\n\u2014 13.6\t+ 4\t+ 12\t+\t8\t+\t2\t4-\tii\t+\t7\t-\t- 7\t\t- 19\t+ 13\t\u2014 4\tH\t-32\t+14\n\u201410.7\t+ 5\t+ 7\t+\t6\t\tI\t+\t7\t+\t4\t-\t- 2\t\t- 17\t4* IO\t\t I\t\t-23\t-Mi\n\u2014 7-5\t+ 3\t+ 9\t\t6\t\u2014\tI\t\ts\t+\t2\t\t- 2\t-\t- 19\t4- ii\t\u2014 3\t-\t-18\t+ \u00ab\n\u2014 3-9\t+ 1\t+ 6\t+\t4\t-f-\t2\t-f\tI\t+\t2\t\t- I\t\tII\t+ 5\t\u2014 S\t-\t-23\t+ 9\n0\t0\t+ 2\t-t-\tI\t\u2014\t3\t+\t4\t-f\tI\t\t- 5\t\t- 3\t\t I\t\t I\t-\t-10\t+ 5\n+ 4-3\t\u2014 I\t\u2014 2\t\u2014\tI\t+\t2\t+\t2\t+\t2\t\t- S\t\t- 2\t\t I\t\t II\t\t- 5\t\u2014 3\n+ 9.0\t\u2014 3\t\u2014 9\t\u2014\t6\t\tO\t\u2014\t2\t\u2014\tI\t\t- 2\t\t- 3\t\u2014 5\t\u2014 14\t\tO\t\u2014 7\n+ 142\t\u2014 3\t\u2014 9\t\u2014\t6\t\u2014\t2\t+\tI\t\tO\t\t- IO\t\t- 5\t\u2014 7\t\u201418\t\t- 2\t\u2014 IO\n+ 19.9\t\u2014 4\t\u2014 9\t\u2014\t6\t\u2014\t3\t\u2014\t3\t\u2014\t3\t\t-15\t\t- 12\t\u2014 13\t\u2014 21\t\t- 6\t\u2014 13\n+ 26.2\t\u2014 5\t\u2014 10\t\u2014\t7\t\u2014\t5\t\u2014\t7\t\u2014\t0\t\t-17\t\t- 5\t\t II\t\u2014 19\t\t- 6\t\u2014 12\n+ 33-1\t\u2014 6\t\u2014 7\t\u2014\t6\t\u2014\t8\t\u2014\t5\t\u2014\t6\t\t-17\t\t- 2\t\u2014 9\t\u201429\t\t- 6\t\u2014 17\n+ 40.7\t\u2014 6\t\u2014 7\t\u2014\t6\t\u2014\t8\t\u2014\t6\t\u2014\t7\t\t-24\t\t- 6\t\u2014 15\t\u201429\t\t- 8\t\u2014 18\n+ 49-0\t\u2014 7\t\u2014 IO\t\u2014\t8\t\u2014\t13\t\u2014\t8\t\tIO\t\t-26\t\t- 5\t\u2014 15\t\u2014 3\u00b0\t\t- 12\t\u2014 21\nAT, O, subjects.\nC, number of millimeters by which the diameter in Set A differed from that in Set B (having a weight of 8o?).\nD1, Du, D, number of grams by which the estimated weight of the block in Set A differed from its true weight, the block being grasped.\nEi, Eu, E, same as D1, Du, D, the block resting on the skin.\nDi, Ei, experiment begun with the lighter blocks.\nDu, Eu, experiment begun with the heavier blocks.\nD, E, averages of Di and Du, and of Ei and Eu respectively.\nFor the sake of comparison the curves obtained by Seashore for the same senses in the seeing are reproduced in Fig. 29 from Fig. 5 of Seashore\u2019s monograph.\nConclusions.\nThe results seem to justify the following conclusions :\n1.\tThe size-weight illusion obtains among the blind.\n2.\tIt follows the same general law as among the seeing, but is not so great either for the muscle sense or for touch as for the same senses among the seeing.\n3.\tThe illusion tends towards the side on which the weight is approached.","page":87}],"identifier":"lit28740","issued":"1897","language":"en","pages":"81-87","startpages":"81","title":"The size-weight illusion among the blind","type":"Journal Article","volume":"5"},"revision":0,"updated":"2022-01-31T15:21:11.590668+00:00"}