1935 年 10 巻 5-6 号 p. 701-723
Problem: What is the structure of the perception when the external objects are not clearly perceived? What changes undergoes the perception, when the illumination is gradually increased? What is the role of the contour lines in the perception? To answer these problems is the object of the present experimental study.
Apparatus and Procedure: Utilizing a Dodge's tachistoscope, figures written on a white paper 126×93mm. in size are presented in a dark room. The illumination of stimulus figures is performed by means of a 30 watt electric lamp. The gradual increase of illumination (from 1.2w to about 7.6w) is adjusted by a water rheostat placed in an adjoining room. The changes of the perception observed by the subjects who look in at the window of the camera, are reported to the experimenter by means of a telephone. The figures used are 20 in number (see Fig. 1, 2, 3 in the Japanese text).
Summary of results:
(1) Before the contour lines in closed figures, and the separate lines in unclosed figures, are not yet perceived, the “playsiviumiy” of the figures as a whole is felt (by which I mean the previous state of dim perception mentioned in (5)). For example, Fig. I and II. are felt as “somehow round” figures; Fig. VII as “a slanting rain”; Fig. XVIII as “a zigzag shaped mountain,” or as “the shape of billows” etc.; Fig. XIV as “square shaped luggage bound with ropes.” In Fig. XIX “something like a human being” is already recognized when the illumination is quite weak.
(2) This fact seems to be felt by the difference between the figure and the ground. (a) In most cases, the inside of the figure looks brighter than the outside. (b) Sometimes along the contour lines, something like a faint shadow is observed. Sometimes, on the contrary, the vicinity of the lines looks particulary brighter; in which case the inside of the figure seems somewhat darker than the outside. (c) In some cases, the surface of the figure or the part enclosed with the sepatate lines seems to stand in relief. In other cases, they appear tinged with different colours, or different in degree as to the homogeneity of the surface.
(3) In unclosed figures, there is a tendency to perceive them closed, so that almost all lines seem prolonged. In such closed figures as Fig. XI, XII, and XIII, diagonals not existing in reality are felt and the feeling remains until the illumination become considerably intense and the perception clear.
(4) Even when the “physiognomy” of the figures as a whole is not yet felt, vanous shapes which have no similarities with the stimulus figures occur especially in the case of the subject R. The reason seems to be due to the phenomena mentioned in(3).
(5) When the figures are dimly perceived, the contour lines are broken, and appear and disappear. Sometimes the movement of their expansion and contraction is reported. In the unclosed figures consisting of groups of lines or dots, the length of the lines is uncertain, their positions and numbers, obscure and especially the extremities indistinct. They appear and disappear at times so that their size fluctuates.
(6) The primacy of Gedalt can be proved by the results of this experiment. The chief of them are: (a) In Fig.II, the distortion of the circle is perceived after the clear perception of the contour. (b)As to the white small circles in Fig III, the small trianges at the corners of the square in Fig. X, and the short oblique lines in Fig. XI, thle results are the Fame.
(7) The sudden expansion of the surface of figures is often observed, when the perception of the figures become clear. In a few cases, on the contrary, the contraction, especially of lines occurs.