How We Experiment on the Mind : Part 6

The Story of the Mind
by James Mark Baldwin

(Page 11 of 15)

Another result came out in connection with these experiments on memory, which, apart from its practical interest, may serve to show an additional resource of experimental psychology. In making up the results of a series of experiments it is very important to observe the way in which the different cases differ from one another. Some cases may be so nearly alike that the most extreme of them are not far from the average of them all; as we find, for example, if we measure a thousand No. 10 shot. But now suppose we mix in with the No. 10 some No. 6 and some No. 14, and then take the average size; we may now get just the same average, and we can tell that this pile is different from the other only by observing the individual measurements of the single shot and setting down the relative frequency of each particular size. Or, again, we may get a different average size in one of two ways: either by taking another lot of uniform No. 14 shot, let us say, or by mixing with the No. 10 a few very large bullets. Which is actually the case would be shown only by the examination of the individual cases. This is usually done by comparing each case with the average of the whole lot, and taking the average of the differences therefore secured - a quantity called the "mean variation."

In the case of the experiments with the squares, the errors in the judgments of the students were found to lie always in one direction. The answers all tended to show that they took, for the one originally shown, a square which was really too large. Casting about for the reason of this, it was considered necessary to explain it by the supposition that the square remembered had in the interval become enlarged in memory. The image was larger when called up after ten or twenty minutes than it was before. This might be due to a purely mental process; or possibly to a sort of spreading-out of the brain process in the visual center, giving the result that whenever, by the revival of the brain process, the mental image is brought back again to mind, this spreading out shows itself by an enlargement of the memory image. However it may be explained, the indications of it were unmistakable - unless, of course, some other reason can be given for the uniform direction of the errors; and it is further seen in other experiments carried out by Messrs. W. and B. and by Dr. K. at a later date.

If this tendency to the enlargement of our memories with the lapse of time should be found to be a general law of memory, it would have interesting bearings. It would suggest, for instance, an explanation of the familiar fact that the scenes of the past seem to us, when we return to them, altogether too small. Our childhood home, the old flower garden, the height of house and trees, and even that of our hero uncle, all seem to the returning traveler of adult life ridiculously small. That we expect them to be larger may result from the fact that the memory images have undergone change in the direction of enlargement.

V. Suggestion. - Space permits only the mention of another research, which, however, should not be altogether omitted, since it illustrates yet other problems and the principles of their solution. This is an investigation by Messrs. T. and H., which shows the remarkable influence of mental suggestions upon certain bodily processes which have always been considered purely physiological. These investigators set out to repeat certain experiments of others which showed that if two points, say those of a pair of compasses, be somewhat separated and put upon the skin, two sensations of contact come from the points. But if while the experiment is being performed the points be brought constantly nearer to each other, a time arrives when the two are felt as only one, although they may be still some distance apart. The physiologists argued from this that there were minute nerve endings in the skin at least so far apart as the least distance at which the points were felt as two; and that when the points were so close together that they only touched one of these nerve endings, only one sensation was produced.

Mr. T. had already found, working in Germany, that, with practice, the skin gradually became more and more able to discriminate the two points - that is, to feel the two at smaller distances; and, further, that the exercise of the skin in this way on one side of the body not only made that locality more sensitive to minute differences, but had the same effect, singularly, on the corresponding place on the other side of the body. This, our experimenters inferred, could only be due to the continued suggestion in the mind of the subject that he should feel two points, the result being an actual heightening of the sensibility of the skin. When he thought that he was becoming more sensitive on one side - and really was - this sense or belief of his took effect in some way in both hemispheres of his brain, and so both sides of the body were alike affected.

This led to other experiments in Princeton in which suggestions were actually made to the subjects that they were to become more or less sensitive to distance and direction between the points on the skin, with the striking result that these suggestions actually took effect all over the body. This was so accurately determined that from the results of the experiments with the compasses on the skin in this case or that, pretty accurate inferences could be made as to what mental suggestions the subject was getting at the time. There was no chance for deception in the results, for the experiments were so controlled that the subject did not know until afterward of the correspondences actually reached between his states of mind and the variations in sensibility of the skin.

This slight report of the work done in one laboratory in about two sessions, involving a considerable variety of topics, may give an idea, so far as it goes, of the sort of work which experimental psychology is setting itself to do. It will be seen that there is as yet no well-knit body of results on which new experiments may proceed, and no developed set of experimental arrangements, such as other positive sciences show. The procedure is, in many important matters, still a matter of the individual worker's judgment and ability. Even for the demonstrations attempted for undergraduate students, good and cheap apparatus is still lacking.

For these reasons it is premature as yet to expect that this branch of the science will cut much of a figure in education. There can be no doubt, however, that it is making many interesting contributions to our knowledge of the mind, and that when it is more adequately organized and developed in its methods and apparatus, It will become the basis of discipline of a certain kind lying between that of physical science and that of the humanities, since it will have features in common with the biological and natural sciences. Its results may be expected also to lead to better results than we now have in the theory and practice of education.

Copyright 1902 by D. Appleton and Company.

About the Author

James Mark Baldwin (1861-1934) was an American philosopher and psychologist who was educated at Princeton under the supervision of Scottish philosopher James McCosh. He made important contributions to early psychology, psychiatry, and to the theory of evolution.