みえの大きさと觀察距離との關係並びに大きさの恒常を規定する要因について (I)

抄録

1. This investigation was undertaken 1) to ascertain whether or not the formula f=φ.d (s=perceived saize, φ=visual angle, d=perceived distance) can generally hold trues; 2) to determine the relation between the perceived size and the viewing distance under various conditions; and to find out, if possible, the main factors which determine size constancy.
2. For testing the first problem, values of s and d were measured experimentally, while φ was kept constant. The experimental objects are cardbord discs or lightened discs, as to the size of which observers might have no particular assumption from their past experience. The result showed that there existed a certain condition in which the formula s=φ.d did not hold true (Table 5; Table 6; Table 7), and further that physically larger objects were perceived nearer than the physically smaller objects (Table 9), under the condition in which the perception of distance was ambiguous.
3. To investigate the second problem, observations were first made in commonplacen surroundings, such as an ordinary room, corridor or balcony, which were physically rectangular in shape, homogeneously lightend and frameworks of which were within the observer's visual field. Such spaces have phenomenally different shapes according to the difference of their physical depth : in cases they are long, their frameworks are perceived to be converging towards the end of the spaces. On the contrary, if they are short, the frameworks are perceived to be diverging, when they are observed binocularly keeping the fixation points at the center of the spaces.
Results indicated that the types of curves showing the relation between the perceived size of objects and veiwing distance depended upon the physical depth of the spaces to which they belonged : that is, the curve ascended where the space was shorter than 5 meters in length (Table 10; Table 13) and descended where the space was longer than 7 meters (Table 11; Table 12), while it was nearly horizontal and liner where the space was 5.5 meters (Table 14). These facts seem to show that the perceived size of an object is determined by the phonomenal shape of the space to which it belongs (Fig. 2).
4. But, when the space 5.5 meters in length was slightly darkened the curve became convex instead of linear (Table 15, Fig. 3). And almost linear curve was obtained when the observation was made in the bright balcony which had the length of 120 meters (Table 16, Fig. 4). These facts seem to show that the flatness of the curve depends on the phenomenal straightness of the framework of the space.
5. Observations made in a completely darkened room revealed that values os Sc/Ss (Ss=physical size of the standard object, Sc=physical size of the comparison object equalled to the standard object) obtained by the ordinary observers were smaller (Group I in Table 18 and 19) than those obtained by the particular observers who had been accustomed to work in this dark room as the experimenter and the assistant (Group II in Table 18; Table 21) : the average Sc/Ss for Group II was nearly 1 up to 4.5 meters even when observed monocularly and above 1 when observed binocularly (Fig. 6). These facts indicate the presence of the effect of past experience on the perception of size.
6. It is to be presumed that the phenomenon of the size constancy in commonplace surroundings is probably a function of the similar kind of past experience with what Group II had, and, hence, that the curves obtained in commonplaces surroundings may coincide with the curves obtained by Group II in the dark room, provided that proper adjustments are made with respect to the differences between these two conditions.
In an attempt to compare these two kinds of curves mentioned above, averagd values of Sc/Ss within a certain range of distances were calculated from the curve obtained by Group II (For explanation of this method, see Fig. 7).