The judgment of very weak sensory stimuli : with special reference to the absolute threshold of sensation for common salt / by Warner Brown.

  • Brown, Warner, 1882-1956.
Date:
1914
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Licence: In copyright

Credit: The judgment of very weak sensory stimuli : with special reference to the absolute threshold of sensation for common salt / by Warner Brown. 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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    i 1914] Brown: The Judgment of Very Weak Sensory Stimuli 209 the sight and taste of the water itself and partly by the continual loss of saliva and consequent dryness of the throat. While the mouth was being rinsed the experimenter was pre- paring the next pipette and entering the judgment. As soon as the rinse Avater had been spit out, the next pipette was handed to the observer. This routine was continued until the series of fifteen or sixteen solutions had been gone through once; then a two-minute rest was taken, and then the routine was resumed.^® answer by an inspection of one of the tables published by Camerer, Ztsch. f. Biol., vol. 21 (1885), p. 601. The distribution of answers found by Camerer when there were 3 bitter, 3 salt, and 2 water cases in each series. The judgments are given in per cent out of 160 for each solution for each of two observers. The upper number refers to Observer I, the lower to Observer II. The method of work was “ unwissentliches, gemischt” as in our own experiments. Salt Solutions Quinine Solutions A A . Jadement No. 2 No. 3 No. 8 No.l No. 1.5 No. 3 Wator Water “Salt” 27.5 66.9 98.7 0.6 52.5 71.9 98.7 .... “Bitter” 1.9 41.2 55.6 81.9 10.0 1.9 0.6 64.4 83.1 90.6 1.2 0.6 “Water” 23.1 9.4 28.7 20.6 6.2 81.1 85.0 15.6 3.7 6.9 1.9 0.6 92.5 97.5 41.9 21.2 1.2 1.2 1.2 0.6 3.7 22.5 19.4 0.6 .... “Uncertain, per- 2.5 1.2 26.2 21.9 10.0 7.5 5.6 haps bitter” 0.6 0.6 22.5 10.0 7.5 5.0 1.2 “Not water, and and not surely 3.1 0.6 2.5 0.6 1.9 0.6 3.1 salt or bitter” 8.1 4.4 1.2 5.6 4.4 1.2 0.6 .... No judgment 0.6 0.6 .... 0.6 0.6 Here three salt, three bitter, and two water stimuli occurred in the series. In this case the judgments “uncertain, perhaps salt” or “uncertain, per- haps bitter” should really be listed as correct judgments. They-are as apt to be right as the ‘ ‘ surely salt ” or “ surely bitter. ’ ’ The judgment ‘ ‘ not water and not surely salt or bitter” is correct in so far as it stands for a sensation which is positive tbut not clear as to quality. “No judgment” gives practically no returns at all; there was always a judgment. Under these circumstances it becomes evident that the doubtful answers, instead of being half right and half wrong, are nearly all right. Under ordinary circumstances, when the alternative of “salt” or “not salt” is offered, the judgment “uncertain” means “uncertain, perhaps salt” as in this table of Camerer’s. It is absurd to decide a priori that half or any part of these judgments are wrong. The rational thing to do is to exclude such judgments from the start. 18 The interval between successive stimulations was much less than is customary in such experiments. Careful preliminary experiments indi-