With this kind of material it was no longer necessary for the operator to show the subject in advance of the series what the movements were in order to avoid hesitation and confusion, for the objects were of such a nature as obviously to suggest in connection with the words the proper movements.

TABLE IV.

SHOWING RECALL AFTER TWO, NINE AND SIXTEEN DAYS FOR TWO SUBJECTS, AND AFTER FIVE HOURS AND TWENTY-ONE HOURS FOR FOUR OTHER SUBJECTS.

Days. Two. Nine. Sixteen Two. Nine. Sixteen N. O. N. O. N. O. V. M. V. M. V. M. Series M. C^{1-4} 4 4 4 4 3 2 3 2 2 2 1 1 C^{5-8} 2 2 2 2 2 1 1 1 1 2 1 0 C^{9-12} 3 2 3 1 3 0 2 4 3 2 2 1 C^{13-16} 4 3(1) 4 2(1) 4 2(1) 3 4 2 3 2 3 Total 13 1(1) 13 9(1) 12 5(1) 9 11 8 9 6 5 Per cent. 81 73 81 60 75 33 56 69 50 56 38 31

Mo C^{1-4} 2 4 1 1 1 1 1 4 1 2 1 2 C^{5-8} 3 2 4 1 3 1 4 3(1) 4 3(1) 2 2(1) C^{9-12} 0 1 0 1 0 1 0 3 0 1 0 2 C^{13-16} 0 0(1) 0 0(1) 0 0(1) 1(1) 4 1(1) 2 0(1) 0 Total 5 7(1) 5 3(1) 4 3(1) 6(1) 14(1) 6(1) 8(1) 3(1) 6(1) Per cent. 31 46 31 20 25 20 40 93 40 53 20 40

Hours. Five. Twenty-one. Five. Twenty-one N. O. N. O. V. M. V. M. Series S. C^{1-4} 1 3 1 1 0 1 0 1 C^{5-8} 0(1) 3 0 2 0 1 0 1 C^{9-12} 0(1) 3 0(1) 4 3 4 3 4 C^{13-16} 1 3 1 3 2 3(1) 3 3(1) Total 2(2) 12 2(1) 10 5 9(1) 6 9(1) Per cent. 14 75 14 63 33 60 40 60

Hn. C^{1-4} 1 4 1 4 0 4 1 4 C^{5-8} 0(2) 1 0(2) 1 0(1) 2 1(1) 2(2) C^{9-12} 3 4 3 4 2 4 2 4 C^{13-16} 1 3 3 3 0 3(1) 0 2(1) Total 5(2) 12 7(2) 12 2(1) 13(3) 4(1) 12(3) Per cent. 36 75 50 75 14 100 29 92

B. C^{1-4} 3 4 3 4 3 4 3 4 C^{5-8} 3 2 3 3 2 2 2 4 C^{9-12} 2 4 2 3 2 1 2 2 C^{13-16} 3 4 3 4 2 4 2 4 Total 11 14 11 14 9 11 9 14 Per cent. 69 88 69 88 56 69 56 88

Ho. C^{1-4} 3(1) 2(2) 3(1) 2(2) 0 3(1) 0 1(1) C^{5-8} 3(1) 4 3(1) 4 3 3(1) 3 3(1) C^{9-12} 1(2) 4 1(2) 4 2(1) 3(1) 2(1) 3(1) C^{13-16} 0 2 0 2 2 4 2 4 Total 7(4) 12(2) 7(4) 12(2) 7(1) 13(3) 7(1) 11(3) Per cent. 58 92 58 92 50 100 50 85

The object series were also changed to conform to the movement series. Formerly the objects had been shown successively through the aperture and synchronously with their corresponding words; now they were on the table in front of the subject and all uncovered and covered at once as in the movement series. The subjects therefore had a single mental image of these four objects also.

In both the object and the movement series the objects as before were small and fairly uniform in size and so selected as not to betray to the subject their presence beneath the cloth in the I. test. In the II., III. and IV. tests there were no objects on the table.

The previous table shows the results of the C set. The figures give the number of couplets correct out of four; the figures in brackets give the number of indirect associations; the total number recalled in any series is their sum.

In the following summary the recall of M and Mo after two days and of S, Hu, B and Ho after twenty-one hours are combined.

SUMMARY FROM TABLE IV.

N. O. V. M. M. 81 per cent. 73 per cent. 56 per cent. 69 per cent. Mo. 31 " 46 " 40 " 93 " S. 14 " 63 " 40 " 60 " Hu. 50 " 75 " 29 " 92 " B. 69 " 88 " 56 " 88 " Ho. 58 " 92 " 50 " 85 " —————- —————- —————- —————- Av. 51 per cent. 73 per cent. 45 per cent. 81 per cent.

Av. gain in object couplets, 22 per cent. " " " movement couplets, 36 per cent.

Before asking whether the results of the C set confirm the conclusions already reached, we must compare the conditions of the three sets to see whether the changes in the conditions in the C set have rendered it incomparable with the other two. The first change was the substitution of dissyllabic words in the verb and the movement series in the place of monosyllabic words. Since the change was made in both the verb and the movement series their comparability with each other is not interfered with, and this is the point at issue. Preliminary tests, however, made it highly probable that simple concrete dissyllabic words are not more difficult than monosyllabic in 5 secs. exposure. This change is therefore disregarded.

The first important change introduced in the C set was the reduction of the intervals between the tests for four subjects. The second was the lengthening of the exposure from 3 to 5 secs. These changes also do not lessen the comparability of the noun, object, verb and movement series with one another, since they affected all series of the C set.

The third change in the conditions was the substitution in the movement series of movements employing objects for movements of the body alone, and the consequent placing of objects on the table in the movement and in the object series of which the subject obtained a single mental image. All of the subjects were of the opinion that this single mental image was an aid in recall. Each of the objects contributing to form it was individualized by its spatial order among the objects on the table. The objects shown through the aperture were connected merely by temporal contiguity. On this account the object and the movement series of the C set are not altogether comparable with those of the A and the B sets. We should expect a priori that the object and the movement series in the C set would be much better recalled than those of the A and the B sets.

The fourth change was from imaged or made movements of the body alone to imaged or made movements employing objects. If, as the A and the B sets have already demonstrated, the presence of objects at all is an aid to recall, the movement series of the C set should show a greater gain over their corresponding verb series than the simple movements of the body in the A and the B sets showed over their corresponding verb series. For, employing objects in movements is adding the aid of objects to whatever aid there is in making the movements.

Turning to the results, we consider the C set by itself with reference to the effect of the use of objects vs. images in general. The summary from Table IV. shows that under the conditions given, after intervals of from slightly less than one day to two days, five of the six subjects recall object couplets better than noun couplets. One subject, M recalls noun couplets better. It also shows that under the conditions and after the intervals mentioned all six subjects recall movement couplets better than verb couplets. In view of the small difference here and of his whole record, however, M is probably to be classed as indifferent in both substantive and action series.

RECALL AFTER NINE AND SIXTEEN DAYS.

Thus far recall after these longer intervals has not been discussed. The experiment was originally devised to test recall after two days only, but it was found that with two of the subjects, M and Mo, recall for greater intervals could be obtained with slight additional trouble. This was accordingly done in the B and C sets. The results of the four other subjects in the B set are not so satisfactory on this point, because not enough was recalled.

The most interesting fact which developed was an apparently slower rate of forgetting, in many cases, of the nouns and verbs than of the objects and movements. In the noun-object group of the B set it is noticeable in three out of the four possible subjects, viz., B, Ho, and Mo. M alone does not show it. The two other subjects, S and B, did not recall enough for a comparison. In the verb-movement group of the B set it is also marked in three out of the four possible subjects, viz., M, Ho, and Mo. B alone does not show it. It is also seen in the C set in the results of M and Mo, in both the noun-object and the verb-movement groups. With the four other subjects in the C set it could not be noticed, since the series ran their course in a day. In M (verb-movement group, C set) and Mo (noun-object group, C set) the originally higher object or movement curves actually fall below their corresponding noun or verb curves.

The results of the tests for recall after nine and sixteen days are summarized in the following tables. They should be compared with the recall of these same series after two days given in Tables II. and IV., nor should it be forgotten that all four types started with perfect immediate recall. The figures give per cents, correct after eliminating indirect-association couplets.

TABLE V.

SHOWING RECALL AFTER NINE AND SIXTEEN DAYS.—SUMMARY FROM B SET.

Days. Nine. Sixteen Nine. Sixteen. N. O. N. O. V. M. V. M. M. 36 38 29 31 56 19 50 31 S. 0 6 0 6 0 7 0 0 Hu. 0 7 0 20 0 25 0 6 B. 13 21 13 13 7 20 7 13 Ho. 25 23 17 0 25 33 0 8 Mo. 57 63 57 56 20 79 20 69 Av. 22 26 19 21 18 31 13 21

TABLE VI.

SAME FOR M AND Mo.—SUMMARY FROM C SET.

Days. Nine. Sixteen. Nine. Sixteen. N. O. N. O. V. M. V. M. M. 81 60 75 33 50 56 38 31 Mo. 31 20 25 20 40 53 20 40

THE D SET.

A few series of nouns, objects, verbs, and movements dissociated from foreign symbols were obtained. The material was of the same kind as the words used in the couplet series, being mostly monosyllabic and seldom dissyllabic words. They had not been previously used with these subjects. Each series contained ten words or ten objects. The same kind of precautions were taken as in the couplet sets to avoid phonetic aids and the juxtaposition of words which suggest each other. The apparatus employed in the couplet sets was used. The objects in the object series were shown through the aperture. Visual images were required in the noun and in the verb series. The noun and the object series were exposed at the rate of one word every 2 secs. (or 20 secs. for the series) for M, S, and Hu, and one every 3 secs. (or 30 secs. for the series) for B, Ho, and Mo. Only one exposure of the series was given. At its completion the subject at once wrote as many of the words or objects as he could recall. Two days later at the same hour he was asked to write without further stimulus as many words of each series as he could recall, classifying them according to their type of series.

The verbs were similar to the verbs of the couplet series. There was a tendency in the verb series among most of the subjects to make a more or less connected story of the verbs and thus some subjects could retain all ten words for two days. This was an element not present in the couplet verb series, according to the subjects, nor in any other series, and the subjects were, therefore, directed to eliminate it by imaging each action in a different place and connected with different persons. The effort was nearly successful, some of the subjects connecting two or three verbs, and others none. The movements employed ten objects which were uncovered and covered by the subject as in the C set. The exposure for the verbs and movements was 5 secs. for each word, or 50 secs. for the series. The tests were the same as in the series of ten nouns and ten objects, but in a number of cases (to be specified in the table) it seemed best to shorten the interval for deferred recall to one day.

The series were always given in pairs—a noun and an object series, or a verb and a movement series forming a pair. Only one pair was given per day and no other series of any kind were given on that day. Usually several days intervened between the II. test of one pair and the learning of the next, but in a little less than half of the cases a new pair was learned on the same day shortly after the II. test of the preceding pair.

The noun-object pairs and the verb-movement pairs were not given in any definite order with reference to each other.

The figures in the following table indicate the number of words out of ten which the subject correctly recalled and placed in their proper columns. Immediate recall is also given.

TABLE VII.

Series. Im. Rec. Two Days. Im. Rec. Two Days. N. O. N. O. V. M. V. M.

M. D^{1-4} 8 9 7 7 7 10 4 5 D^{5-8} 9 7 6 6 8 8 6 6 D^{9-12} 7 7 5 6 8 10 7 7 Av. 24 23 18 19 23 28 17 17

Mo. D^{1-4} 6 6 2 1 8 10 0 7 D^{5-8} 6 5 0 3 8 9 2 4 D^{9-12} 5 7 1 6 10 10 2 7 Av. 17 18 3 10 26 29 4 18

S. D^{1-4} 8 9 2 3 9 10 6 9 D^{5-8} 8 10 2 4 9 10 4 9 D^{9-12} 8 10 2 5 8 10 3 7 Av. 24 29 6 12 26 30 13 25

Hu. D^{1-4} 6 8 3 7 9 10 4 9 D^{5-8} 7 9 0 2 9 10 2 7 D^{9-12} 7 9 4 6 8 10 1 8 Av. 20 26 7 15 26 30 7 24

Ho. D^{1-4} 9 9 3 3 10 9 5 7 D^{5-8} 9 8 1 6 9 9 6 8 D^{9-12} 8 8 5 5 10 10 6 7 Av. 26 25 9 14 29 28 17 22

One day.

The results of the D set strongly confirm the results of the A, B, and C sets. Table VII. shows that after from one to two days' interval four subjects recall objects better than nouns and movements better than verbs. One subject, M., shows no preference.

CONCLUSIONS.

We are now in a position to answer specifically the problem of this investigation. The results show: (1) that those five subjects who recall objects better than nouns (involving images) when each occurs alone, also recall objects better than nouns when each is recalled by means of an unfamiliar verbal symbol with which it has been coupled; (2) that the same is true of verbs and movements; (3) that these facts also receive confirmation on the negative side, viz.: the one subject who does not recall objects and movements better than nouns and verbs (involving images) when they are used alone, also does not recall them better when they are recalled by means of foreign symbols with which they have been coupled.

MINOR QUESTIONS.

The problem proposed at the outset of the investigation having been answered, two minor questions remain: (1) as to images, (2) indirect associations.

1. All the subjects were good visualizers. The images became clear usually during the first of the three presentations, i.e., in 1-3 secs., and persisted until the next couplet appeared. In the second and third presentations the same images recurred, rarely a new one appeared.

An interesting side light is thrown on M.'s memory by his work in another experiment in which he was a subject. This experiment required that the subject look at an object for 10 secs. and then after the disappearance of its after-image manipulate the memory image. M. showed unusually persistent after-images. The memory images which followed were unusually clear in details and also persistent. They were moreover retained for weeks, as was shown by his surprising ability to recall the details of an image long past, and separated from the present one by many subsequent images. His memory was capacious rather than selective. His eyesight was tested and found to be normal for the range of the apparatus. Possibly his age (55 yrs.) is significant, although one of the two subjects who showed the greatest preference for objects and movements, Mo., was only six yrs. younger. The ages of the other subjects were S. 36 yrs., Hu. 23 yrs., B. 25 yrs., Ho. 27 yrs.

That some if not all of the subjects did not have objective images in many of the noun and verb couplets if they were left to their own initiative to obtain them is evident from the image records in the A set, in which the presence of the objective images was optional but the record obligatory. The same subject might have in one noun or verb series no visual images and in another he might have one for every couplet of the series. After the completion of the A set, the effect of the presence of the objective images in series of 10 nouns alone, or 10 objects alone after two days' interval, was tested. This was merely a repetition of similar work by Kirkpatrick after three days' interval, and yielded similar results. As a matter of fact some of the subjects were unable wholly to exclude the objective images, but were compelled to admit and then suppress them as far as possible, so that it is really a question of degree of prominence and duration of the images.

The presence of the objective images having been shown to be an aid in the case of series of nouns, the subjects were henceforth requested to obtain them in the noun and verb series of the B and C sets, and the image records show that they were entirely successful in doing so.

2. The total number of couplets in any one or in several sets may be divided into two classes: (1) Those in which indirect associations did not occur in the learning, and (2) those in which they did occur. For reasons already named we may call the first pure material and the second mixed. We can then ascertain in each the proportion of correctly recalled couplets after one, two, nine and sixteen days' interval, and thus see the importance of indirect associations as a factor in recall. This is what has been done in the following table.

The figures give the number of couplets correctly or incorrectly recalled out of 64. In the case of the interval of one day the figures are a tabulation of the III. test (twenty-one hours) of the C set, which contained 16 series of 4 couplets each. The figures for the intervals of two, nine and sixteen days are a tabulation of the B set, which also contained 16 series of 4 couplets each. C denotes correct, I incorrect.

TABLE VIII.

SHOWING GREATER PERMANENCE OF COUPLETS IN WHICH INDIRECT ASSOCIATIONS OCCURRED.

Pure Material. Mixed Material. Days. One. Two. Nine. Sixteen. One. Two. Nine. Sixteen. C I C I C I C I C I C I C I C I M. 40 22 23 39 22 40 2 0 2 0 3 0 Mo. 36 22 31 27 29 29 6 0 6 0 5 1 S. 27 34 6 55 2 59 1 60 2 1 3 0 3 0 3 0 Hu. 35 22 16 45 5 56 4 57 6 1 3 0 3 0 3 0 B. 48 16 17 43 9 51 7 53 0 0 4 0 1 3 1 3 Ho. 37 15 17 30 13 36 3 46 10 2 9 6 8 7 7 8

Total: 147 87 132 217 83 268 66 285 18 4 27 6 23 10 21 12 P'c't.: 63 37 38 62 24 76 19 81 82 18 82 18 70 30 64 36

We see from the table that the likelihood of recalling couplets in which indirect associations did not occur in learning is 63 per cent. after one day, and that there is a diminution of 44 per cent. in the next fifteen days. The fall is greatest during the second day. On the other hand, the likelihood of recalling couplets in which indirect associations did occur is 82 per cent. after one day, and there is a diminution of only 18 per cent. during the next fifteen days. The fading is also much more gradual.

It is evident, then, that in all investigations dealing with language material the factor of indirect associations—a largely accidental factor affecting varying amounts of the total material (in these six subjects from 3 per cent. to 23 per cent.) is by far the most influential of all the factors, and any investigations which have heretofore failed to isolate it are not conclusive as to other factors.

The practical value of the foregoing investigation will be found in its bearing upon the acquisition of language. While it is by no means confined to the acquisition of the vocabulary of a foreign language, but is also applicable to the acquisition of the vocabulary of the native language, it is the former bearing which is perhaps more obvious. If it is important that one become able as speedily as possible to grasp the meaning of foreign words, the results of the foregoing investigation indicate the method one should adopt.

* * * * *



MUTUAL INHIBITION OF MEMORY IMAGES.

BY FREDERICK MEAKIN.

The results here presented are the record of a preliminary inquiry rather than a definitive statement of principles.

The effort to construct a satisfactory theory of inhibition has given rise, in recent years, to a good deal of discussion. Ever since it was discovered that the reflexes of the spinal cord are normally modified or restrained by the activity of the brain and Setschenow (1863) attempted to prove the existence of localized inhibition centers, the need of such a theory has been felt. The discussion, however, has been mainly physiological, and we cannot undertake to follow it here. The psychologist may not be indifferent, of course, to any comprehensive theory of nervous action. He works, indeed, under a general presumption which takes for granted a constant and definite relation between psychical and cerebral processes. But pending the settlement of the physiological question he may still continue with the study of facts to which general expression may be given under some theory of psychical inhibition not inconsistent with the findings of the physiologist.

A question of definition, however, confronts us here. Can we, it may be asked, speak of psychical inhibition at all? Does one conscious state exercise pressure on another, either to induce it, or to expel it from the field? 'Force' and 'pressure,' however pertinent to physical inquiries, are surely out of place in an investigation of the relations between the phenomena of mind. Plainly a distinction has to be made if we are to carry over the concept of inhibition from the domain of nervous activity to the conscious domain. Inhibition cannot, it should seem, have the same sense in both. We find, accordingly, that Baldwin, who defines nervous inhibition as 'interference with the normal result of a nervous excitement by an opposing force,' says of mental inhibition that it 'exists in so far as the occurrence of a mental process prevents the simultaneous occurrence of other mental processes which might otherwise take place.'[1]

[1] Baldwin, J.M.: 'Dictionary of Philosophy and Psychology,' New York and London, 1901, Vol. I., article on 'Inhibition.'

Even here, it may be said, there is in the term 'prevents' an implication of the direct exercise of force. But if we abstract from any such implication, and conceive of such force as the term inhibition seems to connote, as restricted to the associated neural or physiological processes, no unwarranted assumptions need be imported by the term into the facts, and the definition may, perhaps, suffice.

Some careful work has been done in the general field of psychical inhibition. In fact, the question of inhibition could hardly be avoided in any inquiry concerning attention or volition. A. Binet[2] reports certain experiments in regard to the rivalry of conscious states. But the states considered were more properly those of attention and volition than of mere ideation. And the same author reports later[3] examples of antagonism between images and sensations, showing how the latter may be affected, and in some respects inhibited, by the former. But this is inhibition of sensations rather than of ideas. Again, Binet, in collaboration with Victor Henri,[4] reports certain inhibitory effects produced in the phenomena of speech. But here again the material studied was volitional. More recently, G. Heymans[5] has made elaborate investigation of a certain phase of 'psychische Hemmung,' and showed how the threshold of perception may be raised, for the various special senses, by the interaction of rival sensations, justly contending that this shifting of the threshold measures the degree in which the original sensation is inhibited by its rival. But the field of inquiry was in that case strictly sensational. We find also a discussion by Robert Saxinger,[6] 'Ueber den Einfluss der Gefuehle auf die Vorstellungsbewegung.' But the treatment there, aside from the fact that it deals with the emotions, is theoretical rather than experimental.

[2] Binet, A.: Revue Philosophique, 1890, XXIX., p. 138.

[3] Binet, A.: Revue Philosophique, 1890, XXX., p. 136.

[4] Binet, A., et Henri, V.: Revue Philosophique, 1894, XXXVII., p. 608.

[5] Heymans, G.: Zeitschrift f. Psych. u. Physiol. d. Sinnesorgane, 1899, Bd. XXI., S. 321; Ibid., 1901, Bd. XXVI., S. 305.

[6] Saxinger, R.: Zeitschrift f. Psych. u. Physiol. d. Sinnesorgane, 1901, Bd. XXVI., S. 18.

In short, it appears that though much has been said and done upon the general subject of psychical inhibition, experimental inquiry into the inhibitory effect of one idea upon another—abstraction made, as far as possible, of all volitional influence—virtually introduces us to a new phase of the subject.

The term 'idea,' it should be noted, is here used in its broadest sense, and includes the memory image. In fact, the memory image and its behavior in relation to another memory image formed the material of the first part of the research, which alone is reported here. Apparatus and method were both very simple.

The ideas to be compared were suggested by geometrical figures cut out of pasteboard and hung, 25 cm. apart, upon a small black stand placed on a table in front of the observer, who sat at a distance of four feet from the stand. The diagrams and descriptions which follow will show the character of these figures.

Before the figures were placed in position, the subject was asked to close his eyes. The figures being placed, a few seconds' warning was given, and at the word 'look' the subject opened his eyes and looked at the objects, closing his eyes again at the word 'close.' The time of exposure was five seconds. This time was divided as equally as possible between the two figures, which were simultaneously exposed, the observer glancing freely from one to the other as in the common observation on which our ideas of objects are founded. At the end of the exposure the subject sat with closed eyes and reported the several appearances and disappearances of the ideas or mental images of the objects just presented. The conditions required of him were that he should await passively the entry of the rival claimants on his attention, favoring neither and inhibiting neither; that is to say, he was to remit all volitional activity, save so far as was necessary to restrict his attention to the general field upon which the ideated objects might appear, and to note what occurred on the field. The period of introspection, which followed immediately the disappearance of such retinal images as remained, after the closing of the eyes to the external objects, lasted sixty seconds. The reports, like the signals, were given in a just audible tone. They were in such terms as 'right—left,' 'small—large,' 'circle—star,' terms the simplest that could be found, or such as seemed, in any given case, most naturally or automatically associated with the object, and therefore least likely to disturb the course of the observation. And each report was noted down by the experimenter at the instant it was given, with the time of each phase, in seconds, as indicated by a stop-watch under the experimenter's eye.

It will be remarked that the attitude required of the observer was one which is not commonly taken. And it may be objected that the results of an attitude so unusual towards objects so ghostly and attenuated must be too delicate, or too complex, or influenced by too many alien suggestions, to be plumply set down in arabic numerals. The subjects, in fact, did at first find the attitude not easy to assume. A visual object may hold the attention by controlling the reflexes of the eye. But an ideational object has ordinarily no sure command of the conscious field save under the influence of a volitional idea or some strongly toned affectional state. But with a little practice the difficulty seemed to disappear. The subject became surer of his material, and the mental object gradually acquired the same sort of individuality as the visual object, though the impression it made might be less intense.

After a few preliminary experiments, figures were devised for the purpose of testing the effect of mere difference in the complexity of outline. That is to say, the members of every pair of objects were of the same uniform color-tone (Bradley's neutral gray No. 2), presented the same extent of surface (approximately 42 sq. cm.), were exposed simultaneously for the same length of time (5 seconds), and were in contour usually of like general character save that the bounding line in the one was more interrupted and complex than in the other.

In another series the variant was the extent of surface exposed, the color-tone (neutral gray), outline, and other conditions being the same for both members of each pair. The smaller figures were of the same area as those of the preceding series; in the larger figures this area was doubled. Only one member of each pair is represented in the diagrams of this and the next series.

In a third series brightness was the variant, one member of each pair being white and the other gray (Bradley's cool gray No. 2). All other conditions were for both figures the same.

In still another series strips of granite-gray cardboard half a centimeter wide were cut out and pasted on black cards, some in straight and some in broken lines, but all of the same total length (10 cm.). These were exposed under the same general conditions as those which have already been described, and were intended to show the relative effects of the two sorts of lines.

TABLE I.

1 2 3 4 5 Totals. Averages. L R L R L R L R L R L R L R I. 45 45 25 29 27 27 31 24 36 20 164 145 32.8 29 II. 20 25 28 28 28 19 31 31 28 14 135 117 27 23.5 III. 11 12 17 28 0 7 0 15 27 23 55 85 11 17 IV. 7 6 47 22 17 21 17 45 31 30 119 124 23.8 24.8 V. 27 33 46 36 40 31 44 31 26 35 183 165 36.6 33.2 VI. 11 14 32 29 34 21 14 35 0 46 91 145 18.2 29 VII. 36 33 30 30 50 50 22 22 52 52 190 187 38 37.4 VIII. 41 44 33 33 45 45 34 44 37 28 190 194 38 38.8 IX. 45 45 39 46 42 47 47 47 44 44 217 229 43.4 45.8 X. 40 39 24 25 19 21 21 23 18 25 122 133 24.4 26.6 XI. 51 53 52 50 42 42 42 42 42 42 229 229 45.8 45.8

334 349 373 356 344 331 303 359 341 359 1695 1754 30.8 31.9

The Arabic numerals at the head of the columns refer, in every table, to the corresponding numerals designating the objects in the diagram accompanying the table.

L: left-hand object. R: right-hand object.

The Roman numerals (I to XI) indicate the different subjects. The same subjects appear in all the experiments, and under the same designation. Two of the subjects, IV and VIII, are women.

The numbers under L and R denote the number of seconds during which the left-hand image and the right-hand image, respectively, were present in the period of introspection (60 seconds).

General average: L, 30.8 sec.; R, 31.9 sec.



Series No. 1.—For the purpose of obtaining something that might serve as a standard of comparison, a series of observations was made in which the members of every pair were exact duplicates of each other, and were presented under exactly the same conditions, spatial position of course excepted. The records of these observations are for convenience placed first as Table I.

In treating the facts recorded in the accompanying tables as phenomena of inhibition no assumption is implied, it may be well to repeat, that the ideational images are forces struggling with each other for mastery. Nor is it implied, on the other hand, that they are wholly unconditioned facts, unrelated to any phenomena in which we are accustomed to see the expression of energy. Inhibition is meaningless save as an implication of power lodged somewhere. The implication is that these changes are conditioned and systematic, and that among the conditions of our ideas, if not among the ideas themselves, power is exerted and an inferior yields to a superior force. Such force, in accordance with our general presupposition, must be neural or cerebral. Even mental inhibition, therefore, must ultimately refer to the physical conditions of the psychical fact. But the reference, to have any scientific value, must be made as definite as the case will allow. We must at least show what are the conditions under which a state of consciousness which might otherwise occur does not occur. When such conditions are pointed out, and then only, we have a case of what has been called psychical inhibition; and we are justified in calling it inhibition because these are precisely the conditions under which physiological inhibition may properly be inferred. And, we may add, in order that the conditions may be intelligibly stated and compared they must be referable to some objective, cognizable fact. Here the accessible facts, the experiential data, to which the psychical changes observed and the cerebral changes assumed may both be referred, are visual objects, namely, the figures already described.

What may occur when these objects are precisely alike, and are seen under conditions in all respects alike except as to spatial position, is indicated in Table I. The general average shows that the image referred to the left-hand object was seen some 30 seconds per minute; that referred to the right-hand image, some 31 seconds. Sometimes neither image was present, sometimes both were reported present together, and the time when both were reported present is included in the account. In this series it appears, on the whole, that each image has about the same chance in the ideational rivalry, with a slight preponderance in favor of the right. Individual variations, which may be seen at a glance by inspection of the averages, show an occasional preponderance in favor of the left. But the tendency is, in most cases, towards what we may call right-handed ideation.

Series No. II.—In the second series (Table II.) we find that, other things being equal, an increase in the relative complexity of the outline favors the return of the image to consciousness. Including the time when both images were reported present at once, the simpler appears but 27 seconds per minute as against 34 seconds for the more complex. No attempt was made to arrange the figures on any regularly increasing scale of complexity so as to reach quantitative results. The experiment was tentative merely.

TABLE II.

1 2 3 4 S C S C S C S C I. 21.5 23.5 14.5 35 22.5 21.5 15 27 II. 35.5 21.5 32.5 48 32 33.5 32.5 21.5 III. 27.5 39 20.5 47.5 24.5 46.5 8 22.5 IV. 31.5 26.5 38 23.5 34.5 22 24 29.5 V. 48 50 48 39.5 41.5 51.5 51 47.5 VI. 11.5 35 26.5 28.5 21 33 29 17 VII. 29.5 35 47 47 10.5 52 29.5 33.5 VIII. 12.5 41 32 28.5 13 26.5 17 41.5 IX. 10.5 25.5 27.5 34.5 14.5 44 33 44.5 X. 24 25.5 20 23 16.5 28 23 21 XI. 46 46.5 31.5 53.5 18 53.5 27 50.5

298 369 338 408.5 248.5 412 289 356

5 6 7 Averages. S C S C S C S C I. 20.5 21 14.5 27 7.5 37.5 16.57 27.50 II. 31.5 32 50 45.5 49.5 39.5 37.64 34.50 III. 19.5 32.5 13 31 29 18 20.28 33.85 IV. 40.5 46.5 27 30.5 26 32 31.64 30.07 V. 47.5 47.5 50.5 48.5 38 38 46.35 46.07 VI. 14.5 29 14 33 21 28.5 19.64 29.14 VII. 25.5 43 42.5 30 28 41.5 30.35 40.28 VIII. 8 34 24 27 33 14.5 19.92 30.42 IX. 41.5 27 29.5 27.5 29.5 28 26.57 33.00 X. 10.5 36.5 17 27 18 25 18.42 26.57 XI. 21.5 53.5 40.5 43.5 30 45 30.64 49.42

281 402.5 322.5 370.5 309.5 347.5 27.10 34.62

S: Outline simple.

C: Outline complex.

In this and the following tables the numbers in the body of the columns represent, in each case, the combined result of two observations, in one of which the simpler figure was to the left, in the other the more complex. The figures were transposed in order to eliminate any possible space error.

General average: S, 27.10 sec.; C, 34.62 sec.

Can anything be said, based on the reports, by way of explanation of the advantage which complexity gives? In the first place, the attitude of the subject towards his image seems to have been much the same as his attitude towards an external object: to his observation the image became, in fact, an object. "When the image was gone," says one, "my eyes seemed to be in search of something." And occasionally the one ideated object was felt to exert an influence over the other. "The complex seemed to affect the form of the simpler figure." "It seemed that the complex actually had the effect of diminishing the size of the simpler figure." From time to time the images varied, too, in distinctness, just as the objects of perception vary, and the superior distinctness of the more complex was frequently noted by the subjects. Now the importance of the boundary line in perception is well understood. It seems to have a corresponding importance here. "What I notice more in the simple figure," says one observer, "is the mass; in the complex, the outline." "The simple seemed to lose its form," says another, "the complex did not; the jagged edge was very distinct." And it is not improbable, in view of the reports, that irregularities involving change of direction and increase in extent of outline contributed mainly to the greater persistence of the more complicated image, the 'mass' being in both figures approximately the same. Nor did the advantage of the broken line escape the notice of the subject. "I found myself," is the comment of one, "following the contour of the star—exploring. The circle I could go around in a twinkle." Again, "the points entered the field before the rest of the figure." And again, "the angle is the last to fade away."



Now this mental exploration involves, of course, changes in the direction of the attention corresponding in some way to changes in the direction of the lines. Does this shifting of the attention involve ideated movements? There can be little doubt that it does. "I felt an impulse," says one, "to turn in the direction of the image seen." And the unconscious actual movements, particularly those of the eyes, which are associated with ideated movements, took place so often that it is hard to believe they were ever wholly excluded. Such movements, being slight and automatically executed, were not at first noticed. The subjects were directed, in fact, to attend in all cases primarily to the appearance and disappearance of the images, and it was only after repeated observations and questions were put, that they became aware of associated movements, and were able, at the close of an observation, to describe them. After that, it became a common report that the eyes followed the attention. And as we must assume some central influence as the cause of this movement, which while the eyes were closed could have no reflex relation to the stimulus of light, we must impute it to the character of the ideas, or to their physical substrates.

The idea, or, as we may call it, in view of the attitude of the subject, the internal sensory impression, thus seems to bear a double aspect. It is, in the cases noted, at once sensory and motor, or at any rate involves motor elements. And the effect of the activity of such motor elements is both to increase the distinctness of the image and to prolong the duration of the process by which it is apprehended. The sensory process thus stands in intimate dependence on the motor. Nor would failure to move the eyes or any other organ with the movement of attention, if established, be conclusive as against the presence of motor elements. A motor impulse or idea does not always result in apparent peripheral movement. In the suppressed speech, which is the common language of thought, the possibility of incipient or incomplete motor innervations is well recognized. But where the peripheral movement actually occurs it must be accounted for. And as the cause here must be central, it seems reasonable to impute it to certain motor innervations which condition the shifting of the mental attitude and may be incipient merely, but which, if completed, result in the shifting of the eyes and the changes of bodily attitude which accompany the scrutiny of an external object. And the sensory process is, to some extent at least, conditioned by the motor, if, indeed, the two are anything more than different aspects of one and the same process.[7]

[7] Cf. Muensterberg, H.: 'Grundzuege d. Psychologie,' Bd. I., Leipzig, 1900, S. 532.

But where, now, the subject is occupied in mentally tracing the boundaries of one of his two images he must inhibit all motor innervations incompatible with the innervations which condition such tracing: the rival process must cease, and the rival image will fade. He may, it is true, include both images in the same mental sweep. The boundary line is not the only possible line of movement. In fact, we may regard this more comprehensive glance as equivalent to an enlargement of the boundaries so as to include different mental objects, instead of different parts of but one. Or, since the delimitation of our 'objects' varies with our attitude or aim, we may call it an enlargement of the object. But in any case the mental tracing of a particular boundary or particular spatial dimensions seems to condition the sense of the corresponding content, and through inhibition of inconsistent movements to inhibit the sense of a different content. No measure of the span of consciousness can, of course, be found in these reports. The movements of the attention are subtle and swift, and there was nothing in the form of the experiments to determine at any precise instant its actual scope. All we need assume, therefore, when the images are said to be seen together, is that neither has, for the time being, any advantage over the other in drawing attention to itself. If in the complete observation, however, any such advantage appears, we may treat it as a case of inhibition. By definition, an idea which assumes a place in consciousness which but for itself, as experiment indicates, another might occupy, inhibits the other.



TABLE III.

1 2 3 4 5 6 S L S L S L S L S L S L I. 22 24 19.5 23 20 26 21.5 21 21 26 18 31 II. 31 39 31.5 36 15 32.5 11 22.5 13.5 24.5 7.5 23 III. 10.5 43.5 12 21.5 13 14.5 19 10.5 18.5 30.5 7 18.5 IV. 34.5 29.5 29.5 24 40.5 33 30.5 32.5 15 30 26 30 V. 31.5 30 42 45 39 51 47 49.5 41 37 46 45 VI. 22 20 20.5 22 23.5 22 25 16 24 20 22 25.5 VII. 53.5 53.5 23.5 23.5 47.5 47.5 51 52 52.5 53 51 52 VIII. 34 40.5 23 29 21 22 22 37.5 34.5 35 27.5 28 IX. 19.5 45 19.5 46 22 23.5 23.5 48 26 45.5 19 44.5 X. 16 30.5 12 35 21 24.5 8.5 41 15.5 33 19 28 XI. 38.5 36.5 21 48.5 30 54.5 31 55.5 32 54 12 50

313 392 254 353.5 292.5 381.5 290 386 293.5 388.5 255 375.5

7 8 9 10 Averages S L S L S L S L S L I. 20.5 31.5 21.5 28.5 22.5 28 22.5 26 20.90 26.50 II. 14.5 17.5 19 20 11 4.5 7 30.5 16.10 25.00 III. 10 22 8.5 26 17 16 8 16 12.35 21.90 IV. 27.5 28.5 35 30.5 23.5 46 27.5 49.5 28.95 33.35 V. 40.5 35 24.5 22.5 21 31 21.5 21.5 35.40 36.75 VI. 22.5 18.5 11.5 21 20 27 22.5 24 21.35 21.60 VII. 44.5 46.5 52 51 33.5 49 39.5 50.5 44.85 47.85 VIII. 19.5 20 21 27 19.5 27.5 18.5 22.5 24.05 29.60 IX. 18.5 46 13 42 20 42 18.5 43 19.95 44.90 X. 18.5 24 20.5 21 20.5 22 18.5 28.5 17.00 28.75 XI. 21 49 32 53.5 38 53.5 34.5 46.5 29.00 50.15

257.5 338.5 258.5 343 246.5 346.5 238.5 358.5 24.54 33.30

L: large. S: small.

General average, S, 24.54 sec.; L, 33.30 sec.

Series No. III.—In the third series, where the variant is the extent of (gray) surface exposed, the preponderance is in favor of the image corresponding to the larger object. This shows an appearance of some 33 seconds per minute as against 24 for the smaller (Table III.). Here the most obvious thing in the reports, aside from the relative durations, is the greater vividness of the favored image. Something, no doubt, is due to the greater length of boundary line and other spatial dimensions involved in the greater size. And it is this superiority, and the ampler movements which it implies, which were probably felt by the subject who reports 'a feeling of expansion in the eye which corresponds to the larger image and of contraction in the other.' But the more general comment is as to the greater vividness of the larger image. "The larger images seem brighter whichever side they are on." "The larger is a little more distinct, as if it were nearer to me." "Large much more vivid than small." Such are the reports which run through the series. And they point, undoubtedly, to a cumulative effect, corresponding to a well-known effect in sensation, in virtue of which greater extension may become the equivalent of greater intensity. In other words, the larger image made the stronger impression. Now in external perception the stronger impression tends to hold the attention more securely; that is, it is more effective in producing those adjustments of the sensory organs which perceptive attention implies. So here what was noticed as the superior brightness and distinctness of the larger image may be supposed to imply some advantage in the latter in securing those adjustments of the mental attitude which were favorable to the apprehension of that image. Advantage means here, again, in part at least, if the considerations we have urged are sound, inhibition of those motor processes which would tend to turn attention to a rival. And here, again, the adjustment may reach no external organ. An incipient innervation, which is all that we need assume as the condition of a change of mental attitude, would suffice to block, or at least to hamper, inconsistent innervations no more complete than itself.



TABLE IV.

1 2 3 4 G W G W G W G W I. 15.5 28.5 21.5 32.5 20 33 21 28.5 II. 39.5 23 22.5 22.5 19 20.5 35.5 17.5 III. 13.5 12.5 32 4.5 8.5 10 11.5 11.5 IV. 30 33.5 38 36.5 36 39.5 37.5 13.5 V. 33.5 32.5 34.5 32 33 35 45 36.5 VI. 15 22 21 21 18.5 22 12 22 VII. 53.5 50 43 46 54.5 55 56 56 VIII. 15.5 24.5 24 25 20 13 16.5 21 IX. 17.5 44 9.5 46 18.5 43.5 16 42 X. 25.5 19 29.5 19 21 20.5 23.5 18 XI. 35 42.5 13 29.5 18.5 46 16 38 294 332 288.5 314.5 267.5 338 290.5 304.5

5 6 7 8 G W G W G W G W I. 24 26.5 23.5 25 19.5 30.5 21 29 II. 21 29.5 20 18.5 29 16.5 28.5 14 III. 20.5 8.5 11 11.5 10 14 23 16.5 IV. 39.5 28.5 34.5 22.5 23 30.5 33.5 18 V. 45 53 48 51 45 29 32.5 34.5 VI. 21.5 28 18 32 20.5 19 21.5 18 VII. 54.5 56 54.5 54.5 45 46 49 49 VIII. 24 26.5 23.5 22.5 24 17.5 31 31.5 IX. 16 44 14 43.5 9 43.5 13 44.5 X. 24.5 18 24 21.5 25.5 24 22 22.5 XI. 20.5 8.5 15 36.5 33 23 34 29 311 327 286 339 283.5 293.5 309 306.5

9 10 11 12 Averages. G W G W G W G W G W I. 25 25.5 22.5 21 25 26.5 27 21.5 22.95 27.33 II. 20 25 15 20 29 32 13.5 20 24.37 21.58 III. 12 20 12.5 17.5 10.5 21 3 23 14.00 14.25 IV. 33 19.5 35.5 28 21.5 34.5 25.5 26.5 32.29 27.58 V. 51 50 35 30.5 40.5 54.5 45.5 52.5 40.70 40.91 VI. 13 29.5 25 33.5 28.5 23 23.5 27.5 19.83 24.79 VII. 46.5 39.5 38.5 44.5 43.5 47.5 42.5 34.5 48.41 48.20 VIII. 17.5 25.5 22 15.5 21 29 22.5 21.5 21.79 22.75 IX. 13 43.5 12.5 41.5 15 42 11 40 13.75 43.16 X. 24 24 27 19 25 21.5 23.5 23.5 24.58 20.87 XI. 13.5 49 2.5 43 14 34 23 22 19.83 33.41 268.5 351 248 314 273.5 365.5 260.5 312.5 25.61 29.53

G: Gray. W: White.

General average: G, 25.61 sec.; W, 29.53 sec.

Series No. IV.—This and the next following series do not suggest much that differs in principle from what has been stated already. It should be noted, however, that in the white-gray series (Table IV.) the persistence of the gray in ideation surprised the subjects themselves, who confessed to an expectation that the white would assert itself as affectively in ideation as in perception. But it is not improbable that affective or aesthetic elements contributed to the result, which shows as high a figure as 25 seconds for the gray as against 29 for the white. One subject indeed (IV.) found the gray restful, and gives accordingly an individual average of 32 for the gray as against 27 for the white. More than one subject, in fact, records a slight advantage in favor of the gray. And if we must admit the possibility of a subjective interest, it seems not unlikely that a bald blank space, constituting one extreme of the white-black series, should be poorer in suggestion and perhaps more fatiguing than intermediate members lying nearer to the general tone of the ordinary visual field. Probably the true function of the brightness quality in favoring ideation would be better shown by a comparison of different grays. The general average shows, it is true, a decided preponderance in favor of the white, but the individual variations prove it would be unsafe to conclude directly, without experimental test, from the laws of perception to the laws of ideation.

Series No. V.—The fifth series, which was suggested by the second, presents the problem of the lines in greater simplicity than the second; and, unlike the earlier series, it shows in all the individual averages the same sort of preponderance as is shown in the general average (straight line, 31; broken line, 38). The footings of the columns, moreover, show an aggregate in favor of the broken line in the case of every pair of lines that were exposed together. The results in this case may therefore be regarded as cleaner and more satisfactory than those reached before, and come nearer, one may say, to the expression of a general law. The theoretical interpretation, however, would be in both cases the same.



TABLE V.

1 2 3 4 5 6 L A L A L A L A L A L A I. 28 26.5 24.5 29.5 25 28 26 28.5 26 29.5 25.5 29.5 II. 35 41.5 42 34.5 31.5 47.5 53 50.5 52 52 48 48 III. 16.5 19.5 24 29 41 29.5 35.5 29 21 40 39 40 IV. 40 41.5 37 45 32.5 45.5 36.5 43.5 33.5 38 36.5 43.5 V. 49 53 45 47 45.5 36.5 32.5 51 37 46 40 51 VI. 18 31.5 16 45 22.5 30.5 25 25 24.5 37 25 22 VII. 43 39.5 52 54.5 52.5 53.5 51 54.5 40.5 55 48 48.5 VIII. 23 23 27 29.5 38 40 34.5 32 23 37 42 38.5 IX. 23 48 48 47.5 35 46.5 48 35 28.5 48 46.5 34.5 X. 18 33 19.5 31.5 20.5 30 22 29.5 16.5 35.5 19.5 33 XI. 22.5 33.5 18 41 26 23 19 35.5 5 38 7 50.5

316 390.5 353 434 370 410.5 383 414 307.5 456 377 439

Averages. L A I. 25.83 28.58 II. 43.58 45.66 III. 29.50 31.16 IV. 36.00 42.83 V. 41.50 47.41 VI. 21.83 31.83 VII. 47.83 50.91 VIII. 31.25 33.33 IX. 38.16 43.25 X. 19.33 32.08 XI. 16.25 36.91

31.91 38.54

L: Line (straight line). A: Angle (broken line).

General average: L, 31.91 sec.; A, 38.54 sec.

TABLE VI.

1 2 3 4 5 6 P M P M P M P M P M P M I. 22 32.5 23.5 32 23.5 32 22.5 32.5 23.5 31.5 21 39 II. 24.5 32.5 31.5 49.5 32 39 36 36 33.5 42 28.5 35 III. 8.5 23.5 0 36 0 31.5 11.5 5.5 8.5 14 3.5 8.5 IV. 30 49.5 30.5 42 24 48 27.5 44 28 40.5 43.5 34.5 V. 55.5 55.5 54.5 54.5 46.5 53 34 36 41.5 47 31 35.5 VI. 19.5 22.5 19.5 28 19.5 28.5 26.5 27.5 24.5 29.5 18.5 36 VII. 45 56.5 47.5 55.5 40.5 40 48 54 33.5 50 41 42.5 VIII. 19.5 24 0 40 27.5 20.5 13.5 23 16 25 23 34.5 IX. 28 49.5 26.5 48.5 27.5 45 18 45 21.5 48.5 42.5 44.5 X. 8 43.5 22 29 8.5 43.5 9.5 42.5 16 35 12.5 40.5 XI. 5.5 42.5 7.5 35.5 16.5 35.5 7.5 41 10 41.5 8 32.5

24.18 39.27 23.91 40.95 24.18 37.86 23.14 35.18 23.32 36.77 24.82 34.82

Indiv. Aver. P M I. 22.666 33.250 II. 31.000 39.000 III. 5.333 19.833 IV. 30.583 43.083 V. 43.833 46.916 VI. 21.333 28.666 VII. 42.583 49.750 VIII. 16.583 27.833 IX. 27.333 46.833 X. 12.750 39.000 XI. 9.166 38.083

23.92 37.48

P: Plain. M: Marked.

General average: Plain, 23.92 sec.; Marked, 37.48 sec.

Series No. VI._—Both the figures in each pair of this series were of the same material (granite-gray cardboard) and of the same area and outline, but the content of one of the two was varied with dark lines for the most part concentric with the periphery.

The advantage on the side of the figures with a varied content is marked, the general averages showing a greater difference than is shown in any of the tables so far considered. And the advantage appears on the same side both in the individual averages and in the averages for the different pairs as shown at the foot of the columns. There can be little doubt, accordingly, that we have here the expression of a general law.

For the meaning of this law we may consult the notes of the subjects: 'The plain figure became a mere amorphous mass;' 'the inner lines reinforce the shape, for while previously the number of points in this star has increased (in ideation), here the number is fixed, and fixed correctly;' 'my attention traversed the lines of the content, and seemed to be held by them;' 'the variety of the marked objects was felt as more interesting;' 'the attention was more active when considering the marked figures, passing from point to point of the figure;' 'the surface of the plain figure was attended to as a whole or mass, without conscious activity;' 'in the plain figure I thought of the gray, in the marked figure I thought of the lines;' 'part of the plain figure tended to have lines.'

The part played by the motor elements previously referred to in sustaining attention and prolonging (internal) sensation is here unmistakable. We have further evidence, too, of the value of the line in defining and strengthening the mental attitude. In a mass of homogeneous elements such as is presented by a uniform gray surface, the attention is equally engaged by all and definitely held by none. Monotony therefore means dullness. And the inhibition of incompatible attitudes being as weak and uncertain as the attitudes actually but loosely assumed, the latter are readily displaced, and the sensation to which they correspond as readily disappears. Hence the greater interest excited by the lined figures. The lines give definiteness and direction to the attention, and as definitely inhibit incompatible attitudes. And the shutting out of the latter by the spontaneous activity of the mind means that it is absorbed or interested in its present occupation.

TABLE VII.

1 2 3 4 5 6 5 10 5 10 5 10 5 10 5 10 5 10 I. 29.5 23 24.5 21.5 27 18.5 28 26 27 20 25 29.5 II. 25.5 21 32.5 42.5 19.5 33 27 33.5 26 32 20 28.5 III. 4.5 18.5 12.5 5.5 0 3.5 7.5 11 10.5 18.5 0 7 IV. 33 31.5 28 32 42 44 25 45 38.5 43 41 36.5 V. 35 40.5 35 52.5 28 49.5 43 31 42.5 29 47.5 50.5 VI. 10.5 34.5 10.5 34.5 23 15 26 26.5 22 27 19.5 34.5 VII. 27 42 28.5 19 31.5 49 39 45.5 28.5 50.5 49.5 51.5 VIII. 13.5 21.5 19 15 21.5 18 23 22.5 19.5 18 24.5 21.5 IX. 33 43.5 36 37.5 35 40 26 45 31.5 44 21.5 43.5 X. 20.5 23 22.5 23 23 23.5 22 27.5 21.5 29 21 34.5 XI. 13.5 29 32 16.5 9.5 36.5 40.5 8.5 39.5 8.5 17.5 30.5

22.32 31.50 25.55 27.23 23.64 30.05 27.91 29.27 27.91 29.05 26.09 33.45

7 8 9 10 11 12 5 10 5 10 5 10 5 10 5 10 5 10 I. 22.5 29 27.5 25.5 26 22 22.5 27.5 25.5 25 22 28 II. 29 37.5 32.5 28 34 32 26 23 30.5 28 25.5 23 III. 20.5 8.5 12 16.5 21 9 32 3 21.5 15 8 22 IV. 31 26 39.5 41.5 37 29.5 28.5 37 36.5 30.5 33 31.5 V. 38 34 39 46.5 54 40 32.5 46 43.5 46 36.5 50.5 VI. 30 17 13 25 34.5 26.5 20.5 27 27 35 27.5 33 VII. 55.5 50 42.5 28 50.5 15.5 49 17.5 43.5 29.5 44 26.5 VIII. 16.5 21.5 18 17 17.5 21.5 21 22.5 21.5 23.5 23 27.5 IX. 41 46 45.5 43.5 46.5 33 39 37.5 32 35 33.5 40 X. 24.5 28.5 26.5 24 28.5 25.5 25.5 25 22 30 24 23.5 XI. 19.5 26.5 14 30 42.5 2.5 21.5 30 22.5 33 25.5 24

29.82 29.50 28.18 29.59 35.64 23.36 28.91 26.91 29.64 30.05 27.50 29.96

Indiv. Aver. 5 10 I. 25.58 24.62 II. 27.33 30.16 III. 12.50 11.50 IV. 34.41 35.66 V. 39.54 43.00 VI. 22.00 27.95 VII. 40.75 35.37 VIII. 19.87 20.83 IX. 35.04 40.70 X. 23.45 26.41 XI. 24.83 22.95

27.75 29.15

5: refers to object exposed 5 seconds. 10: refers to object exposed 10 seconds.

General average: (5), 27.75 sec.; (10), 29.15 sec.

Series No. VII.—The object of this series was to determine the effect in ideation of exposing for unequal lengths of time the two objects compared. The figures compared were of the same area and outline, and were distinguished only by their color, one being red and the other green. These colors were employed, after a preliminary test, as showing, on the whole, to nearly equal advantage in the individual choice of colors. The shorter exposure was five seconds and the longer exposure ten seconds. The color that was to be seen the longer time was exposed first alone; after five seconds the other was exposed; and then both were seen for five seconds together, so that neither might have the advantage of the more recent impression. The two colors were regularly alternated, and in one half of the series the longer exposure was to the right, in the other half to the left. The extra five seconds were thus in each case at the beginning of the experiment.

The general averages show only a slight advantage in favor of the color which was exposed the longer time, namely, 29.15 seconds, as against 27.75 seconds. It is not easy to believe that the advantage of sole occupancy of the visual field for five seconds, without any offsetting disadvantage in the next five seconds, should have so slight an effect on the course of ideation. And it is not improbable that there was an offsetting disadvantage. In the presence of color the subject can scarcely remain in the attitude of quiet curiosity which it is easy to maintain in the observation of colorless objects. A positive interest is excited. And the appearance of a new color in the field when there is another color there already seems to be capable of exciting, by a sort of successive contrast different from that ordinarily described, an interest which is the stronger from the fact that the subject has already been interested in a different color. That is to say, the transition from color to color (only red and green were employed) seems to be more impressive than the transition from black to color. And, under the conditions of the experiment, the advantage of this more impressive transition lay always with the color which was exposed the shorter time.

Judging from the introspective notes, the outline seems to suffer, in competition with a colored content, some loss of power to carry the attention and maintain its place in the ideation. "The colors tend to diffuse themselves, ignoring the boundary," says one. "The images fade from the periphery toward the center," says another. On the other hand, one of the subjects finds that when both images are present the color tends to fade out. This may perhaps be explained by the remark of another subject to the effect that there is an alternate shifting of the attention when both images are present. An attitude of continued and definite change, we may suppose, is one in which the color interest must yield to the interest in boundaries and definite spatial relations.

Other interesting facts come out in the notes. One subject finds the ideated plane farther away than the objective plane; another conceives the two as coinciding. The movement of the eyes is by this time distinctly perceived by the subject. The reports run as follows: 'Eye-movements seem to follow the changes in ideation;' 'I find my eyes already directed, when an image is ideated, to the corresponding side, and am sometimes conscious of the movement, but the movement is not intended or willed;' 'in ideating any particular color I find my attention almost always directed to the side on which the corresponding object was seen.' This last observation seems to be true for the experience of every subject, and, generally speaking, the images occupy the same relative positions as the objects: the image of the right object is seen to the right, that of the left object to the left, and the space between the two remains tolerably constant, especially for the full-faced figures.

This fact suggested a means of eliminating the disturbing influence of color, and its contrasts and surprises, by the substitution of gray figures identical in form and size and distinguished only by their spatial position. The result appears in the table which follows (VIII.).

Series No. VIII.—The object of this experiment was the same as that of No. VII. Granite-gray figures, however, were substituted, for the reasons already assigned, in place of the red and green figures. And here the effect of additional time in the exposure is distinctly marked, the general averages showing 32.12 seconds for the image of the object which was exposed 10 seconds, as against 25.42 seconds for the other.

TABLE VIII.

1 2 3 4 5 Indiv. Aver. 5 10 5 10 5 10 5 10 5 10 5 10 I. 26.5 27 24.5 30.5 26.5 28 27.5 27.5 26.5 29 26.3 28.4 II. 32.5 38.5 27 36 29 28 17 14.5 37.5 27 28.6 28.8 III. 4.5 13.5 11 1.5 10 11 7.5 14.5 12.5 8.5 9.1 9.8 IV. 23.5 40.5 27.5 34 35.5 38 35 28 17 39 27.7 35.9 V. 41 46 50 51.5 43 42.5 46 35.5 31.5 44 42.3 43.9 VI. 7.5 27 18 25 21.5 25.5 7 44.5 33.5 19 17.5 28.2 VIII. 24.5 27 34.5 32 36.5 36 34.5 38.5 28 28.5 31.6 32.4 IX. 17 46 25.5 47.5 44 47 40.5 47.5 48 48 35.0 47.2 X. 20 29 21 26.5 25.5 24.5 27.5 22 19.5 23.5 22.7 25.1 XI. 11 41.5 9.5 50 5.5 43.5 15.5 40.5 25.5 32 13.4 41.5 20.80 33.60 24.85 33.45 27.70 32.40 25.80 31.30 27.95 29.85 25.42 32.12

VII.—Absent.

5: refers to object exposed 5 seconds. 10: refers to object exposed 10 seconds.

General average: (5), 25.42 sec.; (10), 32.12 sec.

The interpretation of this difference may be made in accordance with the principles already laid down. The ideated and actual movements which favor the recurrence and persistence of an idea are, on grounds generally recognized in psychology, much more likely to occur and repeat themselves when the corresponding movements, or the same movements in completer form, have frequently been repeated in observation of the corresponding object.

TABLE IX.

1 2 3 4 5 Indiv. Aver. 1st 2d 1st 2d 1st 2d 1st 2d 1st 2d 1st 2d I. 22.5 32.5 27 28 26.5 28 26.5 27.5 26 29 25.7 29.0 II. 4.5 43 9 29 3.5 38 0 43 17 44.5 6.8 39.5 III. 0 22 0 20.5 9.5 16.5 0 23.5 3.5 9.5 2.6 18.4 IV. 0 31 1 35.5 4.5 39 16.5 32.5 16 20.5 7.6 31.7 V. 24 52.5 41.5 40 12 53.5 22 55 22 50.5 24.3 50.3 VII. 1.5 52 0 48 0 54.5 0 50.5 0 46.5 0.3 50.3 VIII. 12 26 10 27.5 11.5 23.5 13.5 28.5 15.5 20 12.5 25.1 IX. 24 43.5 20 42 25 42.5 20.5 44.5 28 42.5 23.5 43.0 X. 9 45.5 19.5 30 11 33 12 38 14.5 30 13.2 35.3 XI. 12.5 35 23.5 29.5 1 49 2 44 10.5 52 9.9 41.9 11.00 38.30 15.15 33.00 10.45 37.75 11.30 38.70 15.30 34.50 12.64 36.45

VI.—Absent.

From this point on the place of Miss H. (IV.) is taken by Mr. R. The members in each pair of objects in this group were not exposed simultaneously.

1st: refers to object first exposed. 2d: refers to object last exposed.

General average: 1st, 12.64 sec.: 2d, 36.45 sec.

What is here called ideated movement—by which is understood the idea of a change in spatial relations which accompanies a shifting of the attention or a change in the mental attitude, as distinguished from the sense of movements actually executed—was recognized as such by one of the subjects, who says: "When the two objects are before me I am conscious of what seem to be images of movement, or ideated movements, not actual movements." The same subject also finds the image of the object which had the longer exposure not only more vivid in the quality of the content, but more distinct in outline.

Series No. IX.—In this experiment the objects, which were of granite-gray cardboard, were exactly alike, but were exposed at different times and places. After the first had been exposed five seconds alone, it was covered by means of a sliding screen, and the second was then exposed for the same length of time, the interval between the two exposures being also five seconds. Two observations were made with each pair, the first exposure being in one case to the left and in the other case to the right. The object here was, of course, to determine what, if any, advantage the more recent of the two locally different impressions would have in the course of ideation. The table shows that the image of the object last seen had so far the advantage in the ideational rivalry that it remained in consciousness, on the average, almost three times as long as the other, the average being, for the first, 12.64 seconds; for the second, 36.45 seconds. And both the individual averages and the averages for the several pairs show, without exception, the same general tendency.

The notes show, further, that the image of the figure first seen was not only less persistent but relatively less vivid than the other, though the latter was not invariably the case. One subject had 'an impression that the images were farther apart' than in the series where the exposure of the two objects was simultaneous, though the distance between the objects was in all cases the same, the time difference being, apparently, translated into spatial terms and added to the spatial difference. The sort of antagonism which temporal distinctions tend, under certain conditions, to set up between ideas is illustrated by the remark of another subject, who reports that 'the attention was fairly dragged by the respective images.' And the fact of such antagonism, or incompatibility, is confirmed by the extremely low figure which represents the average time when both images were reported present at the same time. The two images, separated by processes which the time interval implies, seem to be more entirely incompatible and mutually inhibitory than the images of objects simultaneously perceived. For not only does the advantage of a few seconds give the fresher image a considerable preponderance in its claim on the attention, but even the earlier image, after it has once caught the attention, usually succeeds in shutting out the other from a simultaneous view.

TABLE X.

1 2 3 4 5 Indiv. Aver. V H V H V H V H V H V H I. 27.5 27 26.5 28 30.5 24.5 27.5 28.5 26 25 27.60 26.60 II. 45 43.5 37 40 35.5 28.5 19 15.5 30.5 30.5 33.40 31.60 III. 19 21 0 10.5 19.5 19 9 15 4.5 16 10.40 16.30 IV. 47.5 39 36 22.5 44.5 41.5 47.5 46 37 36 42.50 37.00 V. 56.5 46.5 42.5 42.5 48 45.5 48.5 48.5 53 52 49.70 47.00 VI. 31.5 28.5 30.5 30.5 22 34.5 34.5 28.5 25 26.5 28.70 29.70 VII. 55 55 55 45.5 38 20 55.5 53.5 56 56 51.90 45.80 VIII. 39.5 47 23.5 23.5 19 18.5 26.5 26.5 26 20.5 26.90 27.20 IX. 26.5 46 38 42.5 41 44 40.5 46.5 35.5 39 36.30 43.60 X. 24.5 25 26 25 25.5 23 23.5 28.5 32.5 20.5 26.40 24.40 XI. 52 52 56.5 54.5 48 49.5 45 47.5 51.5 47.5 50.60 50.20

38.60 39.14 33.77 33.09 33.77 31.68 34.27 34.95 34.31 33.60 34.94 34.49

V: Vertical. H: Horizontal.

General average: Vertical, 34.94 sec.; Horizontal, 34.49 sec.

Series No. X.—The objects used in this experiment were straight lines, two strips of granite-gray cardboard, each ten centimeters long and half a centimeter wide, the one being vertical and the other horizontal. These were pasted on black cards and exposed in alternate positions, each appearing once to the right and once to the left. The figures in the columns represent in each case the combined result of two such observations.

The experiments with these lines were continued at intervals through a number of weeks, each individual average representing the result of ten observations, or of five pairs of exposures with alternating objects.

The striking feature in the observations is the uniformity of the results as they appear in the general averages and in the averages for each pair as shown at the foot of the columns. There is some variation in the individual tendencies, as shown by the individual averages. But the general average for this group of subjects shows a difference of less than half a second per minute, and that difference is in favor of the vertical line.

This series will serve a double purpose. It shows, in the first place, that on the whole the vertical and the horizontal lines have a nearly equal chance of recurrence in image or idea. It will serve, in the second place, as a standard of comparison when we come to consider the effect of variations in the position and direction of lines.

TABLE XI.

1 2 3 4 5 Indiv. Av. F O F O F O F O F O F O I. 24 31 26.5 28.5 27 29 22 33.5 27.5 28 25.4 30.0 II. 53.5 50 52.5 52.5 56.5 55.5 43.5 43.5 56 51.5 52.4 50.6 III. 3 21.5 4 20 11 17 3.5 27 0 20.5 4.3 21.2 IV. 26.5 30 11 48.5 12.5 53 12 51 23 51 17.0 46.7 V. 40.5 56.5 48 56 55.5 55.5 53 55.5 53.5 55.5 50.1 55.58 VI. 27.5 40.5 23 31.5 24.5 32.5 31 29 27 33.5 26.6 33.4 VII. 50.5 54 53.5 56.5 53.5 53.5 40.5 52 55 55 50.6 54.2 VIII. 1 33.5 11 27 5 32 7.5 39 4.5 36.5 5.8 33.6 IX. 35.5 41.5 45.5 47 41.5 41.5 39 44.5 41 41.5 40.5 43.2 X. 19 30.5 21.5 30.5 21 29.5 16 37.5 22.5 30.5 20.0 31.7 XI. 11.5 52.5 18 51.5 14.5 50.5 23 50.5 15 52.5 16.4 51.5 26.59 40.14 28.59 40.86 29.32 40.86 26.45 42.09 29.55 41.45 28.10 41.08

F: Full-faced. O: Outlined.

General average: full-faced, 28.10 sec.; outlined, 41.08 sec.

Series No. XI.—In this series full-faced figures were compared with outline figures of the same dimensions and form. Material, granite-gray cardboard. The area of the full-faced figures was the same as that of the figures of similar character employed in the various series, approximately 42 sq. cm.; the breadth of the lines in the outline figures was half a centimeter. The objects in each pair were exposed simultaneously, with the usual instructions to the subject, namely, to regard each object directly, and to give to each the same share of attention as to the other.

The form of the experiment was suggested by the results of earlier experiments with lines. It will be remembered that the express testimony of the subjects, confirmed by fair inference from the tabulated record, was to the effect that lines show, in ideation as in perception, both greater energy and clearer definition than surfaces. By lines are meant, of course, not mathematical lines, but narrow surfaces whose longer boundaries are closely parallel. To bring the superior suggestiveness of the line to a direct test was the object of this series. And the table fully substantiates the former conclusion. For the outline figure we have a general average of 41.08 seconds per minute, as against 28.10 seconds for the full-faced figure.

The notes here may be quoted as corroborative of previous statements. "I notice," says one, "a tendency of the color in the full-faced figure to spread over the background"—a remark which bears out what has been said of the relative vagueness of the subjective processes excited by a broad homogeneous surface. To this may be added: "The full-faced figures became finally less distinct than the linear, and faded from the outside in;" "the areal (full-faced) figure gradually faded away, while the linear remained." Another comment runs: "I feel the left (full-faced) striving to come into consciousness, but failing to arrive. Don't see it; feel it; and yet the feeling is connected with the eyes." This comment, made, of course, after the close of an observation, may serve as evidence of processes subsidiary to ideation, and may be compared, in respect of the motor factors which the 'striving' implies, with the preparatory stage which Binet found to be an inseparable and essential part of any given (vocal) motor reaction.[8]

[8] Binet, A. et Henri, V.: op. citat.

Series No. XII.—Both the figures of each pair in this series were linear, and presented the same extent of surface (granite-gray) with the same length of line. In other words, both figures were constituted of the same elements, and in both the corresponding lines ran in the same direction; but the lines in the one were connected so as to form a figure with a continuous boundary, while the lines of the other were disconnected, i.e., did not inclose a space. The total length of line in each object was twenty centimeters, the breadth of the lines five millimeters. Both figures were arranged symmetrically with respect to a perpendicular axis.



TABLE XII.

1 2 3 4 5 Indiv. Av. L F L F L F L F L F L F I. 31.5 24 30 24.5 23.5 32 25.5 30.5 27 29.5 27.5 28.1 II. 55 55 56 56 56 56 56.5 56.5 54 54 55.5 55.5 III. 22 6 26.5 9.5 31.5 1.5 23 5.5 28.5 0 26.3 4.5 IV. 31 15 46.5 20.5 52 9.5 49 6 55 18 46.7 13.8 V. 56 54 56 56 56 56 56.5 56.5 55.5 55.5 56.0 55.6 VI. 33 30 34 39.5 31.5 29.5 26.5 32 26 31.5 30.2 32.5 VII. 55.5 49.5 56.5 38 54.5 35 57.5 32.5 38 27 52.4 36.4 VIII. 26.5 15.5 21.5 13.5 25 17 25.5 21 15 13.5 22.7 16.1 IX. 45.5 32.5 44.5 39 42.5 35.5 41.5 37.5 43 40.5 43.4 37.0 X. 29.5 23 36.5 16 23 28.5 35.5 16.5 29 23 30.7 21.4 XI. 52 8 49.5 19 45.5 25 43.5 21.5 15 31.5 41.1 21.0 39.77 28.41 41.77 30.18 40.10 29.60 40.05 28.73 35.10 29.50 39.32 29.26

L: Interrupted lines. F: Figure with continuous boundary. (Figure in outline.)

General average: Lines, 39.32 sec.; figure, 29.26 sec.

The experiment was devised in further exploration of the effect of the line in ideation. The result fully bears out, when read in the light of the introspective notes, what has been said of the importance of the motor element in ideation. It might have been supposed, in view of the importance usually attached to unity or wholeness of impression in arresting and holding the attention in external perception, that the completed figure would have the more persistent image. The general averages, however, stand as follows: Interrupted lines, 39.32 seconds per minute; completed figure, 29.26 seconds per minute. The individual averages show slight variations from the tendency expressed in these figures, but the averages for the several pairs are all in harmony with the general averages.

The notes furnish the key to the situation: "I felt that I was doing more, and had more to do, when thinking of the broken lines." "The broken figure seemed more difficult to get, but to attract attention; continuous figure easy to grasp." "Felt more active when contemplating the image of the broken figure." "In the broken figure I had a feeling of jumping from line to line, and each line seemed to be a separate figure; eye-movement very perceptible." The dominance of the interrupted lines in ideation is evidently connected with the more varied and energetic activity which they excited in the contemplating mind. Apparently the attention cannot be held unless (paradoxical as it may sound) it is kept moving about its object. Hence, a certain degree of complexity in an object is necessary to sustain our interest in it, if we exclude, as we must of course in these experiments, extraneous grounds of interest. Doubtless there are limits to the degree of complexity which we find interesting and which compels attention. A mere confused or disorderly complex, wanting altogether in unity, could hardly be expected to secure attention, if there is any truth in the principle, already recognized, that the definite has in ideation a distinct advantage over the vague. Here again the notes suggest the method of interpretation. "The broken lines," says one, "tended to come together, and to take the form of the continuous figure." Another remarks: "The broken figure suggests a whole connected figure; the continuous is complete, the broken wants to be." In virtue of their power to excite and direct the activity of the attention the interrupted lines seem to have been able to suggest the unity which is wanting in them as they stand. "The broken lines," says another, "seemed to run out and unite, and then to separate again"—a remark which shows a state of brisk and highly suggestive activity in the processes implied in attention to these lines. And a glance at the diagram will show how readily the union of the broken lines may be made. These were arranged symmetrically because the lines of the completed figures were so arranged, in order to equalize as far as possible whatever aesthetic advantage a symmetrical arrangement might be supposed to secure.

It thus appears that, whatever the effect in ideation of unity in the impression, the effect is much greater when we have complexity in unity. The advantage of unity is undoubtedly the advantage which goes with definiteness of impression, which implies definite excitations and inhibitions, and that concentration of energy and intensity of effect in which undirected activity is wanting. But a bare unity, it appears, is less effective than a diversified unity. To what extent this diversity may be carried we make no attempt to determine; but, within the limits of our experiment, its value in the ideational rivalry seems to be indisputable. And the results of the experiment afford fresh proof of the importance of the motor element in internal perception.

TABLE XIII.

1 2 3 4 5 Indiv. Av. F V F V F V F V F V F V I. 25 29 26 29 29.5 26.5 25.5 30 24.5 31 26.1 29.1 II. 56 56 55 55 54 54.5 47.5 47.5 45 50 51.5 52.6 III. 2.5 5.5 2.5 8.5 6.5 5 16.5 9.5 17 15 9.0 8.7 IV. 48 48 31.5 31.5 31 46 51.5 51.5 35 52 39.4 45.8 V. 54 54 56.5 52 56 56 56 56 54 56 55.3 54.8 VI. 39 29 30 33.5 35.5 22.5 32.5 34 33.5 24.5 34.1 28.7 VII. 46 55 54.5 46.5 46.5 50 49.5 54 47 46 48.7 50.3 VIII. 9 14.5 23 20.5 23.5 22 18 14.5 16 17 17.9 17.7 IX. 43 43 46.5 46.5 45.5 45.5 43.5 43.5 46 47.5 44.9 45.2 X. 28 26.5 21 29.5 26.5 26.5 21.5 31.5 25 29 24.4 28.6 XI. 23.5 46 19.5 35.5 20 46 24 47.5 28.5 19.5 23.1 38.9 34.00 36.95 33.27 35.27 34.05 36.41 35.09 38.14 33.77 35.23 34.03 36.40

F: Figure (in outline). V: Vertical lines.

General average: Figure, 34.03 sec.; vertical lines, 36.40 sec.

Series No. XIII.—In this series, also, both the figures of each pair were constituted of the same elements; that is to say, both were linear, and presented the same extent of surface (granite-gray), with the same length of line, the total length of the lines in each figure being twenty centimeters and the breadth of the lines being three millimeters. But while the lines of one figure were connected so as to form a continuous boundary, the lines of the other figure were all vertical, with equal interspaces. And, as in the last preceding series, the two figures were formed by a different but symmetrical arrangement of the same lines.

As before, the advantage is on the side of the disconnected lines. In this case, however, it is very slight, the general averages showing 34.03 seconds for the completed figure, as against 36.40 seconds for the lines. This reduction in the difference of the averages is probably to be explained by the reduced complexity in the arrangement of the lines. So far as they are all parallel they would not be likely to give rise to great diversity of movement, though one subject does, indeed, speak of traversing them in all directions. In fact, the completed figures show greater diversity of direction than the lines, and in this respect might be supposed to have the advantage of the lines. The notes suggest a reason why the lines should still prove the more persistent in ideation. "The lines appealed to me as a group; I tended always to throw a boundary around the lines," is the comment of one of the subjects. From this point of view the lines would form a figure with a content, and we have learned (see Series No. VI.) that a space with a varied content is more effective in ideation than a homogeneous space of the same extent and general character. And this unity of the lines as a group was felt even where no complete boundary line was distinctly suggested. "I did not throw a boundary around the lines," says another subject, "but they had a kind of unity." It is possible also that from the character of their arrangement the lines reinforced each other by a kind of visual rhythm, a view which is supported by the comments: 'The lines were a little plainer than the figure;' 'figure shadowy, lives vivid;' 'the figure grew dimmer towards the end, the lines retained their vividness.'

On the whole, however, the chances are very nearly equal in the two cases for the recurrence of the image, and a comparison of this series with Series No. XII. cannot leave much doubt that the greater effectiveness of the lines in the latter is due to their greater complexity. In view, therefore, of the fact that in both series the objects are all linear, and that the two series differ in no material respect but in the arrangement of the disconnected lines, the circumstance that a reduction in the complexity of this arrangement is attended by a very considerable reduction in the power of the lines to recur in the image or idea is a striking confirmation of the soundness of our previous interpretation.

Series No. XIV.—In this series full-faced figures (granite-gray) similar in character to those made use of in former experiments, were employed. The objects were suspended by black silk threads, but while one of them remained stationary during the exposure the other was lowered through a distance of six and one half centimeters and was then drawn up again. The object moved was first that on the right hand, then that on the left. As the two objects in each case were exactly alike, the comparative effect of motion and rest in the object upon the persistence in consciousness of the corresponding image was obtained. The result shows a distinct preponderance in favor of the moved object, which has an average of 37.39 seconds per minute as against 28.88 seconds for the stationary object. The averages for the pairs, as seen at the foot of the columns, all run the same way, and only one exception to the general tendency appears among the individual averages.

TABLE XIV.

1 2 3 4 5 Indiv. Av. S M S M S M S M S M S M I. 22.5 28.5 25 30.5 24.5 28 28 27.5 25.5 31 25.1 29.6 II. 47.5 55 53 42 48.5 53.5 34.5 39.5 49 52 46.5 48.4 III. 3 18 7.5 8.5 0 7.5 0 3.5 0 4 2.1 8.3 IV. 45 45 33.5 51.5 11 50.5 11 50 8 52.5 21.7 49.9 V. 54.5 51 53.5 54.5 49 51 30.5 38.5 56 55 48.7 50.0 VI. 21 32.5 26 33 29.5 37.5 30 35 30 36 27.3 34.8 VII. 48 55 56.5 49 41.5 54.5 44.5 53 35.5 54 45.2 53.1 VIII. 10.5 20.5 20.5 25 6 33 12.5 29.5 19 18 13.7 25.2 IX. 37.5 43.5 34.5 45 36 47.5 30 47.5 29 48.5 33.4 46.4 X. 13 39.5 18 34 19 33.5 19 33 10.5 44 15.9 36.8 XI. 17.5 43.5 47.5 32 27.5 36 46 16.5 52 16 38.1 28.8

29.09 39.27 34.14 36.82 26.59 39.55 26.00 33.95 28.59 37.36 28.88 37.39

S: Refers to figure left stationary. M: Refers to figure that was moved during exposure.

General average: S, 28.88 sec.; M, 37.39 sec.

The effectiveness of a bright light or of a moving object in arresting attention in external perception is well understood. And the general testimony of the subjects in this experiment shows that it required some effort, during the exposure, to give an equal share of attention to the moving and the resting object. Table IV., however, which contains the record of the observations in the white-gray series, shows that we cannot carry over, unmodified, into the field of ideation all the laws that obtain in the field of perception. The result of the experiment, accordingly, could not be predicted with certainty. But the course of ideation, in this case, seems to follow the same general tendency as the course of perception: the resting object labors under a great disadvantage. And if there is any force in the claim that diversity and complexity in an object, with the relatively greater subjective activity which they imply, tend to hold the attention to the ideated object about which this activity is employed, the result could hardly be other than it is. There can be no question of the presence of a strong motor element where the object attended to moves, and where the movement is imaged no less than the qualities of the object. In fact, the object and its movement were sometimes sharply distinguished. According to one subject, 'the image was rather the image of the motion than of the object moving.' Again: 'The introspection was disturbed by the idea of motion; I did not get a clear image of the moving object; imaged the motion rather than the object.' And a subject, who on one occasion vainly searched the ideational field for sixty seconds to find an object, reports: 'I had a feeling of something going up and down, but no object.' Clearly an important addition was made to the active processes implied in the ideation of a resting object, and it would be singular if this added activity carried with it no corresponding advantage in the ideational rivalry. In one case the ideas of rest and of movement were curiously associated in the same introspective act. "The figure which moved," says the subject, "was imaged as stationary, and yet the idea of movement was distinctly present."

The reports as to the vividness of the rival images are somewhat conflicting. Sometimes it is the moving object which was imaged with the more vivid content, and sometimes the resting object. One report runs: "The moving object had less color, but was more distinct in outline than the stationary." Sometimes one of the positions of the moving object was alone represented in the image, either the initial position (on a level with the resting object) or a position lower down. On the other hand, we read: "The image of the moved object seemed at times a general image that reached clear down, sometimes like a series of figures, and not very distinct; but sometimes the series had very distinct outlines." In one case (the circle) the image of the figure in its upper position remained, while the serial repetitions referred to extended below. This, as might be supposed, is the report of an exceptionally strong visualizer. In other cases the object and its movements were not dissociated: "The moved object was imaged as moving, and color and outline were retained." And again: "Twice through the series I could see the image of the moving object as it moved." "Image of moved object moved all the time."

TABLE XV.

1 2 3 4 5 Indiv. Av. Gray Red Gray Yellow Gray Green Gray Blue Gray Violet Gray Colored.

I. 26 29 27.5 28.5 26.5 29 21.5 27.5 27.5 26.5 25.8 28.1 II. 35.5 36.5 45.5 53.5 53.5 53.5 53.5 53.5 55 55 48.6 50.4 III. 0 11 2.5 19 10.5 16 17.5 8.5 0 9 6.1 12.7 IV. 45 23.5 8 53.5 48 39 48 52 55.5 35 40.9 40.6 V. 55.5 55.5 42 53 50 56 52.5 50 44.5 56.5 49.1 54.2 VI. 22 33.5 29 36.5 28 43.5 26 37.5 39.5 29 28.9 36.0 VII. 38.5 39 56 56 49.5 54.5 47 47 45.5 50 47.3 49.3 VIII. 15 10.5 15 19.5 23 21 19.5 24 20.5 25 18.6 20.0 IX. 31.5 49 19 42.5 50 50 35.5 46 48 39 36.8 45.3 X. 19 33 14.5 37 29.5 23 17 37.5 23 31 20.6 32.3 XI. 11 49.5 8 51.5 9 43.5 35 43.5 24 47 17.4 47.0 27.18 33.64 24.27 40.95 34.32 39.00 33.91 38.82 34.82 36.64 30.90 37.81

General average: Gray, 30.90 sec.; colored, 37.81 sec.

Series No. XV.—The figures in each pair of this series were full-faced, and of the same shape and size, but one was gray and the other colored, the gray being seen first to the left, and then to the right. The colors used were of Prang's series (Gray, R., Y., G., B., V.). In No. 1 the figures were in the form of a six-pointed star, and gray was compared with red. In No. 2 the figures were elliptical, and gray was compared with yellow. In No. 3 a broad circular band of gray was compared with the same figure in green. In No. 4 the figures were kite-shaped, and gray was compared with blue. In No. 5 a circular surface of gray was compared with a circular surface of violet. The objects compared were exposed at the same time, under the usual conditions.

As might perhaps be expected, the colored surfaces proved to be the more persistent in ideation, showing a general average of 37.81 seconds per minute as against 30.90 seconds for the gray.

The distinctness of the process of color apprehension is reflected in the notes: "In the colored images I find the color rather than the form occupying my attention; the image seems like an area of color, as though I were close to a wall and could not see the boundary;" and then we have the significant addition, "yet I feel myself going about in the colored area." Again: "In the gray the outline was more distinct than in the colors; the color seems to come up as a shade, and the outline does not come with it." Or again: "The gray has a more sharply defined outline than the color." This superior definiteness in outline of the gray figures is subject to exceptions, and one subject reports 'the green outline more distinct than the gray.' And even so brilliant a color as yellow did not always obscure the boundary: "The yellow seems to burn into my head," says one of the subjects, "but the outline was distinct." The reports in regard to this color (yellow) are in fact rather striking, and are sometimes given in terms of energy, as though the subject were distinctly conscious of an active process (objectified) set up in the apprehension of this color. The reports run: "The yellow has an expansive power; there seemed to be no definite outline." "The yellow seemed to exert a power over the gray to suppress it; its power was very strong; it seemed to be aggressive."

TABLE XVI.

1 2 3 4 5 a b a b a b a b a b I. 0 0 0 0 0 0 0 0 0 0 II. 43 41 33 51 19 31 32 41 20 18 III. 0 6 0 0 3 11 13 16 0 0 IV. 56 28 23 35 0 11 48 56 35 25 V. 56 55 44 44 57 30 39 32 34 30 VI. 14 8 12 12 11 5 35 12 9 6 VII. 52 54 56 56 51 47 56 57 47 26 VIII. 15 0 18 21 24 39 26 10 23 21 IX. 28 25 39 31 23 28 26 36 25 17 X. 0 0 0 0 0 0 0 0 0 0 XI. 52 45 41 48 7 39 50 36 48 22 35.11 29.11 29.55 33.11 21.66 26.78 29.55 26.91 21.91 15.00

Series No. XVI.—The course of experimentation having shown the superior energy of lines, in comparison with surfaces, in stimulating, directing, and holding the attention, a series of figures was devised to test the question whether the direction of the lines would have any effect upon the length of time during which both images of a pair of linear figures would be presented together. The materials used were granite-gray strips half a centimeter wide. The letters (a) and (b) at the heads of the columns refer to the same letters in the diagram, and distinguish the different arrangements of the same pair of objects. The figures in the body of the columns show only the length of time during which both images were reported present in consciousness together. At the foot of the columns are shown the averages for each pair. No general averages are shown, as the problem presented by each pair is peculiar to itself.



The maximum is reached in No. 1a, where the angle has the arrowhead form and each angle points to the other. It should be remarked that the diagram is somewhat misleading in respect to the distance of the figures, which in this as in the other experiments was 25 cm. The figures therefore were far enough away from each other to be perceived and imaged in individual distinctness. But the 'energy' of the lines, especially where the lines united to form an acute angle, was often sufficient to overcome the effect of this separation, and either to bring the figures nearer together or to unite them into a single object. The notes are very decisive in this regard. A few of them may be cited: "The angles tended to join points." "The figures showed a tendency to move in the direction of the apex." "The angles (2a) united to form a cross." "When both figures (4b) were in mind I felt disagreeable strains in the eyeballs; one figure led me to the right and the other to the left." The effect of the last-named figures (4a) seemed to be different from that of 1a and 2a, though the apex of each angle was turned to that of the other in each of the three cases. "The two angles," says another subject, speaking of 4a, "appeared antagonistic to each other." It will be observed that they are less acute than the other angles referred to, and the confluent lines of each figure are far less distinctly directed towards the corresponding lines of the opposing figure, so that the attention, so far as it is determined in direction by the lines, would be less likely to be carried over from the one image to the other.

On the other hand, when the angles were turned away from each other the legs of the angles in the two figures compared were brought into closer relation, so that in 2b, for instance, the average is even higher than in 2a. Similarly the average in 3b, an obtuse angle, is higher than in 3a. The notes show that in such cases the contrasted angles tended to close up and coalesce into a single figure with a continuous boundary. "The ends (2b) came together and formed a diamond." "When the angles were turned away from each other the lines had an occasional tendency to close up." "There was a tendency to unite the two images (4a) into a triangle." "The two figures seemed to tug each other, and the images were in fact a little closer than the objects (4a)." "The images (4a) formed a triangle." So with regard to the figures in 5a. "When both were in the field there seemed to be a pulling of the left over to the right, though no apparent displacement." "The two figures formed a square."

The lowest average—and it is much lower than any other average in the table—is that of 5b, in which the contrasted objects have neither angles nor incomplete lines directed to any common point between the objects. In view of the notes, the tabulated record of these two figures (5b) is very significant, and strikingly confirms, by its negative testimony, what 1a and 2b have to teach us by their positive testimony. The averages are, in the three cases just cited: 1a, 35.11 seconds; 2b,33.11 seconds; 5b, 15 seconds per minute.

On the whole, then, the power of the line to arrest, direct, and keep the attention, through the greater energy and definiteness of the processes which it excites, and thereby to increase the chances of the recurrence and persistence of its idea in consciousness, is confirmed by the results of this series. The greatest directive force seems to lie in the sharply acute angle. Two such angles, pointing one towards the other, tend very strongly to carry the attention across the gap which separates them. (And it should be borne in mind that the distance between the objects exposed was 25 cm.) But the power of two incomplete lines, similarly situated, is not greatly inferior.

It thus appears that the attention process is in part, at least, a motor process, which in this case follows the direction of the lines, acquiring thereby a momentum which is not at once arrested by a break in the line, but is readily diverted by a change in the direction of the line. If the lines are so situated that the attention process excited by the one set is carried away from the other set, the one set inhibits the other. If, on the other hand, the lines in the one set are so situated that they can readily take up the overrunning or unarrested processes excited by the other set, the two figures support each other by becoming in fact one figure. The great importance of the motor elements of the attention process in ideation, and thus in the persistence of the idea, is evident in either phase of the experiment.

RECAPITULATION.

Seconds Seconds. 1 Figures alike: Left 30.8 Right 31.9 2 " unlike: Simple 27.10 Complex 34.62 3 " " Small 24.54 Large 33.30 4 " " Gray 25.61 White 29.53 5 " " Line 31.91 Angle 38.54 6 " " Plain 23.92 Marked 37.48 7 " " (colored) 5 seconds 27.75 10 seconds 29.15 8 " " (gray) 5 seconds 25.42 10 " 32.12 9 " " 1st exposure 12.64 2d exposure 36.45 10 " " Vertical line 34.94 Hor. line 34.49 11 " " Full-faced 28.10 Outline 41.08 12 " " Figure 29.26 Int. lines 39.32 13 " " Figure 34.03 Vert. lines 36.40 14 " " Stationary 28.88 Moved 37.39 15 " " Gray 30.90 Colored 37.81 16 (See Table XVI.)