現象的速度に及ぼす挾角の影響について

抄録

The present experiments were conducted to find out how the change in the apparent length of and aperture caused by attaching a pair of arrowheads on both ends of it, affects the phenomenal velocity of moving objects behind the aperture.
Two apparatus (one for the standard and the other for the comparison) are placed in front of the subject on a table in a dark room, and illuminated by a reflector lamp. An aperture (3mm × 15cm) is horizontally opened in the middle of a white paper (30cm × 63cm) which is placed in front of each of the apparatus. Behind the aperture is a moving belt on which black rectangles (3mm × 5mm) are distributed at an interval of 5mm. Arrowheads with different angles and with 6cm sides are attached on both ends of the aperture. The belt of the standard apparatus moves with the speed of 5cm/sec, and the subject is asked to adjust the visual speed of the moving objects in the comparison-apparatus to that of the standard.
Results :
Exp. 1. Without attached arrowheads the decrease of the aperture length resulted in the increase of the phenomenal velocity of moving objects.
Wxp. 2. With arrowheads pointing towards the center of the aperture the object was seen faster than with arrowheads pointing away from the center of the aperture.
Exp. 3. The presence of the arrowheads always increased the phenomenal velocity.
Exp. 4. The effect of putting two lines perpendicular to the edge of the aperture on visual velocity was smaller than those of any other cases.
Exp. 5, 6. From the results based on data from the measurement of illusion caused by a pair of arrowheads, we could not recognize that the change of the aperture's apparent length caused by illusion had any effect on the phenomenal velocity.
The difference in the distance from the ends of the arrowheads to the center of the aperture had no effect on the phenomenal velocity.
The difference in the area of the total extensions sustained by two arrowheads had a considerable effect on the phenomenal velocity.
Exp. 7. The apparent length of the aperture was shortened by the motion of the moving objects.
Exp. 8, 9. The intenser the figures showed the character as a reference-point (‘an anchorage’) to the moving objects, the more the phenomenal velocity increased.
Conclusion :
The effect of arrowheads attached to both ends of the aperture on the phenomenal velocity, would be generally caused by the following two factors : (1) the difference in the total extension sustained by two arrowheads, and (2) the strength acting as a reference-point to the moving objects. so far as our experimental condition were concerned, the change of the aperture's apparent length by illusion did not act as a factor in the change of the phenomenal velocity.