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 | 30.5 | 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. | 03 | 18 | 07.5 | 08.5 | 00 | 07.5 | 00 | 03.5 | 00 | 04 | 2.1 | 8.3 |
| IV. | 45 | 45 | 33.5 | 51.5 | 11 | 50.5 | 11 | 50 | 08 | 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 | 06 | 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."