抄録
In the previous articles (1, 2), highly unexpected results were reported which the authors encountered in a series of experiments employing a particular set of pre-illuminating stimuli (Fig. 1 in 2) and dealing with the indirect induction. Namely, the authors made discoveries strongly suggesting the interpretation that, under certain circumstances, the configuration of the indirect induction can not be understood in terms of the pattern of the retinal stimulation. In short, if, I, II, III and IV of Fig. 1 in (2) are presented in succession and fixation is shifted from the left mark to the right one at an appropriate moment prior to the presentation of IV, existence or non-existence of the induction at each point follows the pattern designated P in Fig. 2 in (2). The P-result seems to be accounted for only by the assumption that the configuration of the induction takes its form in accordance with what a subject perceives under the given conditions. On the contrary, if I, II and IV are presented in succession and fixation is shifted in the same way, the results turn to what designated R in Fig. 2 in (2). The R-result is easy to understand in terms of the retinal stimulation pattern.
In one of the present experiments, the configuration of the direct induction was examined with the same pre-illuminating stimuli (Fig. 1 in 2). As shown in Fig. 1, the results were exactly parallel to those obtained in the case of the indirect induction. That means, when III was included, the result doubtlessly supported the P-hypothesis, whereas, when III was omitted, the R-hypothesis became tenable.
In order to obtain further informations concerning these findings, a series of experiments were designed with the pre-illuminating stimuli as shown in Fig. 2 which involve so-called refraction of a beam of the induction initiated from B in II. When III was included, the arrival of the induction from B to the point 2 was demonstrated by the neutralization of induction of Y at this point (Fig. 5). This is what we called the P-result accompanying the refraction in addition. It is astonishing that the refraction takes place in the region of the retina which isnot stimulated at all by the prism-shaped yellow figure in I. Besides, the refraction index was discovered to coincide with that obtained by Motokawa in the retinal region actually pre-illuminated by the prism shaped figure. On the other hand, when III was omitted, the neutralization was observed at the point 6 and the R-result was obtained (Fig. 7). Hence, it may be said that the results are highly consistent throughout all the experiments reported so far.
