TABLE II

SUBJECTS, ORAL STIMULI AND IST, 2D, AND 3D JUDGMENTS OF ANOSMIC AND CONTROL SUBJECTS

Note: In the above table "?" represents doubt expressed by the subject. In a few cases substances were missed with one or both controls. The serial order of words represents the order of the subject's judgments.

that the breath was to be held preceding and during the two judgments to prevent the passage of particles by air to the nasal epithelium by way of the choana. Later (with the controls still blinded) the cotton plugging was removed and the experiments were repeated; here the subject was allowed to breathe normally.

The results of these 'recognition' experiments are presented in Table II.

Examination of the foregoing table reveals that, with the possible exception of two or three judgments, Subject Y correctly named the oral stimulus on each second judgment, while neither of the controls could name it correctly with the frequency of Y until the third judgment, which was based upon both mastication, with its attendant cues, and smell. Subject Y's nostrils were unclosed during his second judgments so that, in this respect, these judgments were comparable to the third judgments of the control subjects. His anosmic condition, however, and the correctness of his second judgments, as contrasted with the doubts expressed by the controls on some of their third judgments, would rate Y's second judgments as being superior to those of the controls when they had the additional aid of smell. At any rate, the results seem to demonstrate that, in spite of his anosmia, he is as efficient as normal persons who cannot see, in naming correctly the substance or object placed in his mouth and that he is superior to the blindfolded person who is deprived of smell. The table also suggests that secondary cues may have been of great significance not only to the anosmic

2 That kinæstheses and other syntheses do play rôles in what are regarded as comparatively simple perceptions has been demonstrated by S. W. Fernberger, An introspective analysis of the process of comparing, Psychol. Monog., 1919, 26; J. Philippe & J. Claviere, Rev. phil., 1895, 40, 672–682; H. N. Loomis, Psychol. Monog., 1907, 8, 334-348; L. B. Hoisington, Amer. J. Psychol., 1920, 31, 114-146; E. Shults, Amer. J. Psychol., 1922, 33, 135–139; A. S. Baker, Amer. J. Psychol., 1922, 33, 139–144; Mueller & Schumann, Pflüger's Arch., 1889, 45; Goldscheider (see Ortmann, J. Comp. Psychol., 1923, 3, 12-14); Woodworth, ibid., p. 15; Fechner & Steffens, Zsch. f. Psychol., 1900, 23; C. N. Waterman, J. Exp. Psychol., 1917, 2, 289–294; and syntheses, possibly not involving kinæstheses, in comparatively simple perceptions have been demonstrated by I. Bershansky, Amer. J. Psychol., 1922, 33, 584-587; 1923, 34, 291-295; Cobbey & Sullivan, ibid., 1922, 33, 121–127; and L. Knight, ibid., 1922, 33, 587-590.

subject but also to the controls in reaching both judgments one and two and also judgment three. These secondary cues were in the nature of such characteristics as warmth or coldness, roughness or smoothness, hardness or softness, slickness, stinging and burning. Unfortunately our results contain no descriptions of kinæstheses, except perhaps as these are included in the above listed secondary cues, and no suggestions are given as to their importance in acts of recognizing and judging.

As we have already observed, we had no way of knowing what sensitivities and what abilities of oral recognition our anosmic subject possessed before his accident. He may always have excelled the normal person in the ability to judge, without relying on smell, the nature of food placed in the oral cavity. It is an intriguing possibility, however, that, following upon his accident, practice in using, and dependence upon, secondary cues led to improvement so that he became more skillful than the control subjects.

We have arrived, in summary, at the following conclusions.

1. Subject Y is anosmic; and his anosmia is probably complete.

2. His taste sensitivity, considering only the usual four taste qualities, was not impaired by the accident and its consequences.

3. Our experimental results seem to indicate that his gustatory sensibility has not been made more acute by the accident and by subsequent practice.

4. Y's ability to name correctly the object placed in his mouth even though unaided by vision excelled that possessed by two control subjects under similar conditions.

5. Y's skill in naming food stimuli was developed, as we believe, by the circumstances of his being compelled to attend to and to rely upon secondary cues in his experiences of the anosmic year prior to our observations.

BIBLIOGRAPHY

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A CURVE OF GROWTH DESIGNED TO REPRESENT

THE LEARNING PROCESS

BY H. J. ETTLINGER

Department of Mathematics, University of Texas

Thurstone has recently determined an empirical equation for the learning process in the form of an hyperbola,3

2

where Y = attainment in terms of the number of successful

and

(2)

acts performed per unit period,

X = amount of practice in terms of total number of
practice acts,

L = limit of attainment in terms of the number of
successful acts performed per unit period,
R = ratio of LY to the rate of change of Y with
regard to X.

To evaluate R and L, Thurstone "rectifies" equation (1) as

If X/Y is plotted against X, the graph of (2) is a straight line. The straight line which yields the "best" fit for the experimental data is determined by (1) inspection, (2) the method of three equidistant points, (3) the theory of least squares, or (4) the method of the regression equation. The latter two methods give approximately the same values for R and L.

1 L. L. Thurstone, The learning curve equation, Psychol. Monog. (Stud. Psychol. Lab. Univ. of Chicago), 1919, 26 (no. 114), 1–51.

* Suitable restrictions are made to safeguard the validity of the conclusions. The process is typified by typewriter learning (op. cit., introd., pp. 1, 2, 11).

A modified form of the equation is given in which X is replaced by X + P, where P represents the actual or equivalent practice previous to the experiment. However, by setting X' = X + P the modified form returns to equation (1), where initially X' has the value P.