NUMERICAL.
As each movement may be compared with three other movements, and as there were five subjects and four variations in the conditions, there are sixty opportunities of comparing the time required to move the image in the direction in which the object was moved with the time taken to move it in the other directions. In 45 instances the time was less, in 3 the same, and in 12 greater.
These twelve instances occurred with two subjects, three (to left) occurring with K. and nine (three each right, up, down) occurring with H. The cause was the same in all twelve instances, both H. and K. reporting that (in these cases) they had great difficulty in obtaining a reasonably vivid and distinct image when directed to move the image in the direction in which the object had been moved. The attempt to move the image resulted in a vague image spread continuously over the entire area that had been covered by the moving object, and the effort to obtain the image at the desired position only was serious and took an appreciably longer time than usual. It is to be noted, also, that the time usually taken by H. is uniformly very much greater than the time taken by the other subjects. Yet, even with these instances included, the average time of all movements of the image in the direction in which the object had been moved is less than the average time of the other movements, the former being 2.41 seconds, the latter, 2.59 seconds.
TABLE VIII.
MOVEMENTS OF A SINGLE IMAGE.
I., OBJECT PREVIOUSLY MOVED; II., OBJECT NOT MOVED.
Average Time Given in Seconds.
| Subjects: | B. | G. | H. | I. | K. | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| I | II | I | II | I | II | I | II | I | II | |||||||||||
| To right, | 0.57 | 1.30 | 0.55 | 1.46 | 6.95 | 7.15 | 2.05 | 1.28 | 2.35 | 4.80 | ||||||||||
| Return, | 0.35 | 0.58 | 0.27 | 0.92 | 5.40 | 4.51 | 1.15 | 0.67 | 1.17 | 2.40 | ||||||||||
| To left, | 0.60 | 1.06 | 0.45 | 1.15 | 5.95 | 6.42 | 1.30 | 1.34 | 2.57 | 4.63 | ||||||||||
| Return, | 0.40 | 0.73 | 0.35 | 0.89 | 4.10 | 4.41 | 1.22 | 0.62 | 1.60 | 2.73 | ||||||||||
| Up, | 0.42 | 1.05 | 0.45 | 0.99 | 6.85 | 5.96 | 1.85 | 1.62 | 1.42 | 3.29 | ||||||||||
| Return, | 0.42 | 0.46 | 0.25 | 0.76 | 5.30 | 4.36 | 0.87 | 0.86 | 1.27 | 1.90 | ||||||||||
| Down, | 0.57 | 1.10 | 0.47 | 0.82 | 8.77 | 5.85 | 1.80 | 1.36 | 2.30 | 3.27 | ||||||||||
| Return, | 0.42 | 0.45 | 0.27 | 0.06 | 5.55 | 4.40 | 1.42 | 0.72 | 1.25 | 1.56 | ||||||||||
| General | 0.54 | 1.13 | 0.48 | 1.10 | 7.13 | 6.34 | 1.75 | 1.40 | 2.16 | 4.00 | ||||||||||
| Averages, | 0.40 | 0.55 | 0.28 | 0.66 | 5.09 | 4.42 | 1.16 | 0.72 | 1.32 | 2.15 | ||||||||||
If the record of H. is omitted from Table VII., a, c, and d, and that of K. from VII., b (as these are the records of the twelve exceptions), the former average becomes 1.44 seconds, the latter 1.86 seconds.
The following table affords the means of comparing the time taken in moving the image in the direction in which the object had been moved with the time taken in moving the image in the same direction when there had been no movement of the object. The averages are obtained from the records of Tables VII. and I.
We have here twenty comparisons each of movements away from the original positions and movements back to the original positions:
In the first case, 15 took less time under I., 5 took more time under I.
The 5 cases of more time occurred with two subjects (H., 3 and I., 2).
In the second case, 12 took less time under I., 8 took more time under I.
The 8 cases of more time occurred with three subjects (G., 1; H., 3; I., 4).
If we omit H.'s record and take the general averages for each subject, we find the following advantages in time in form of movements where the object had been moved;
| B., | 0.59 | seconds. |
| G., | 0.52 | " |
| K., | 1.84 | " |
But I., 0.35 seconds in favor of movements when the object had not been moved.
Combining these results, we have 0.74 sec. as the average gain in time for these four subjects.
SUBJECTIVE.
With one exception (G.), the subjects found Movements I., movements in the direction in which the object had been moved, easier than Movements II. In Movements II. the eye seemed to construct and compel the motion, which was not the case with Movements I., in which the eye followed the motion. The distance to which the image went in Movements I. seemed predetermined, and these movements seemed exact copies of the original movement of the object, being purely reminiscent and reproducing its irregularities when there were any. Also, the image was usually seen in transitu both out and back, which was never the case with Movements II. Eye movement and enunciation were much less frequent and the image was more vivid and distinct in Movements I.
FOOTNOTES.
1 Gallon, Francis: 'Inquiries into Human Faculty and its Development,' London, 1883, p. 109.
2 Bentley, I.M.: 'The Memory Image and its Qualitative Fidelity,' Am. Journ. of Psychol., 1899, XI., pp. 1-48.
3 Ladd, G.T.: 'Direct Control of the Retinal Field,' PSYCH. REV., 1894, L, pp. 351-355.
4 French, F.C.: PSYCH. REVIEW, 1902, IX., p. 40.