The present investigation, as the previous one, was designed to study the effect of an extra line upon the successive comparison of the lengths of two lines. In the previous investigation the effect of the extra line, which preceded two lines to be compared or was interpolated between them, upon the comparison of two lines was studied. The present study was conducted to see whether the comparison of two lines underwent a modification when the extra line followed them. Three black lines on a white background were horizontally presented in succession at an identical location for the same brief durations. Of the two lines compared, a standard line of 30mm. in length preceded the comparison line in the majority of experimental series. The time intervals between the lines were varied within a short period and the PSE under each condition was determined by using the method of complete series. If the PSE thus obtained way larger or smaller than that obtained without the presen-tation of the extra line, it was understood that the comparison line was underestimated or overestimated due to the Presence of the extra line.
The results were as follows : for convenience, the writer referred to the standard to the standard line as N, to the comparison line as V and to the extra as i.
1. When i was 60, 45, or 30mm., underestimation of V occurred regardless the time intervals between the lines.
2. When i was 15 or 7.5mm. and the time intervals were short, underestimation of V occurred. However, if the time interval N-V was short and the interval V-i was relatively longer than the interval N-V, overestimation appeared. Moreover, if the interval V-i was further lengthend, V again became underestimated.
3. When i was 15 or 7.5mm. and the time interval V-i was short, while the interval N-V was much longer than the interval V-i, then overestimation occurred.
4. Without the presence of the extra line, a negative time error was obtained, in general, in both previous and present studies irrespective of the time interval and the duration of the lines, although the error became less marked as the observers were repeatedly exposed to observation.
Since the retroactive effect of the extra stimulus upon the comparison of the extents of two stimuli which preceded the extra stimulus was confirmed, it might be inferred that the judgments reported by the observer for the extents of the stimuli did not always arise before the exposure of the extra stimulus. Considering these facts, the process of comparative judgment was discussed and the trends in the modifications of comparison, as mentioned in the above items, were ascribed to various manifestations of an assimilation-contrast phenomenon.

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It is now generally accepted that guessing sequences are sufficient to account for the ‘spread of effect’ phenomenon. This is based on experimental facts such as : (1) the gradient of number repetitions similar to the Thorndike effect was found after chance repetitions which were not rewarded (Sheffield and Jenkins), (2) the gradient disappeared when stimulus positions were changed during trials but it was found if only step positions were considered, stimulus positions being ignored (Zirkle) and (3) the effect did not appear or it was greatly reduced after non-repeated rewarded responses while it was clearly shown after repeated rewarded responses (Jenkins and Sheffield).
Unfortunately none of these findings were strong enough to refute the effect theory of the Thorndike effect on the basis of the facts that (1) this orthodox Thorndike effect and number guessings may not be principally the same, (2) the change of stimulus positions during trials does necessarily interfere with the ‘spread of effect’and would reduced the gradielt and (3) non-repeated rewarded responses may not be actually rewarded simply because they are not repeated. The purpose of this experiment was to test the theory of guessing habit when these factors were controlled.
Two groups, 50 undergraduate students each, were used as Ss. Group M was presented with two lists 24 two-syllabled Japanese nouns, for three seconds per each word. Ss were required to read them aloud and to respond to them with a number from one through 10. An orthodox instruction for the ‘spread of effect’ experiment was utilized, such as, “If you call out the right Numbers”, I shall say ‘right’and if you call out any other numbers I shall say ‘wrong’. Your task is to try to repeat the numbers called ‘right’ and to avoid the numbers called ‘wrong’ when the stimulus list is presented again .......
List 1 was shown three times in succession. Responses to the sixth and 17th stimuli were called ‘right’ and those to any other responses were called ‘wrong’ irrespective of the numbers given. This prearranged pattern was sometimes modified but was consistent for any one S. The instruction was changed after List 2 was read twice. Ss were asked to recall the numbers they gave last time and to say whether the number was called ‘right’ or ‘wrong’. Stimulus words for the two lists were interchanged from S to S.
Group N was the same as Group M except that the stimuli consisted of nonsense words rather than meaningful nouns.
Our experimental hypothesis were that (1) the mean number of correctly recalled responses would be greater for Group M than for the other group because of the very nature of the stimulus characteristics and (2) the gradient of number repetitions would be, on the other hand, greater for Group N as compared with Group M because the S-R connection would interfere with the guessing habit.
The results confirmed the predictions. The negative relation between correctly recalled responses and response repetitions strongly suggested that the Thorndike effect was very different from the ordinary S-R connections. Although the guessing sequence hypothesis would predict a high positive correlation between the repetition of rewarded responses and that of first errors, the obtained r was not large enough (-.244) to confirm the prediction for Group M, and the same r was almost zero (-.011) for Group N. This finding, however, was not very conclusive but if strengthened by further experimentation, it would require some modification of the theory of guessing sequences. It should be added that only the aftergradients were observed for both groups.

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As known quite well, the figural aftereffect occurs in such a way that the apparent extent of the test figure is affected when an inspection figure precedes the test figure, while a so-called assimilation-contrast illusion of the visual extent takes place when they are presented simultaneously. In the present investigation, the effect of the inspection figure upon the estimation of the test figure, besides both of the above mentioned effects, was confirmed, when the test figure precedes the inspection figure. We call this effect“retroactive figural-effect”. The black contour circles on a white card were presented in succession by a revised Dodge-tachisto-scope and Harvard time-apparatus. The spatial arrangement of figures in shown in Fig. 1 where an inspection figure (I) and a test figure (T) of 30mm. in diameter are found on the left side of a fixation point and a comparison figure (C) which is variable in size with 1mm. steps is on the right side. T and C were always presented simultaneously. The PSE was determined by the method of complete series, and it was checked against the constant error in PSE due to possible inhomogeneity between the right and left visual fields. The final results were as follows :
1. The retroactive-effect of I. upon the estimation of the extent of T. was conspicuous when I. followed T. The retroactive-effect varied with the extent of I. in a similar manner to that of the figural after-effect, although the amount of the effect was less than that of the latter. T. was underestimated when I. was equal to or larger than T. while it was overestimated when I. was smaller than T. (See Fig. 2)
2. The amount of the retroactive-effect. varied not only with the exposure duration of I. but also with the time interval between T. and I. (See. Fig. 3 and 4).
3. When T. and I. were presented simultaneously, the typical assimilation illusion of concentric circles was obtained, viz., T. was overestimated or underestimated according to whether it was smaller or larger than I. (See Fig. 5).
4. The transition from the simultaneous effect to the figural after-effect or the retroactive-effect occurred at such a temporal interval where the impression of succession of T. and I. appeared on the part of subjects. (See Fig. 5 and Table 7).
5. Even if I. was exposured 900 msec. later after the disappearance of T., the retroactive-effect was observed when the observers only with held their verbal reports with respect to the extent of T. until the disappearance of I.. However, if the verbal reports were made immediately after the exposure of T. and C., this effect became weak (See Table 4). These facts seem to suggest that the retroaction became effective through some complex processes involving not only perceptual process but also the memory trace.
The results of the present investigation indicate that the adequate theory of the figural after-effect must take into consideration fhe retroaction and the simultaneous induction.

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Purpose : The purpose of the present experiment is to testify various conditioned generalizations on verbal activities by means of conditioning GSR on vocal stimulus and, thereby, to analize individual relations among several verbal activities. This experimental program is arrange to the reports given by C. V. Hugins and R. Menzies and other scholars, and is based on C. E. Noble's experimental data in paticular. The present test is, however, limited to only such task as evidencing a certain dominant factor in relations to the conditioning processes, and does not refer to the problem of volition.
Experimental procedures : For this experiment, five subjects in all, 5 female and 2 male students, were used to testify the hypothesis that the GSR conditioned on a temporal stimulus compound, consisting of ra light and a self-initiated vocal stimulus, can be generalized to several verbal activities. The experiment has the following four stages :
(1) To examine the relative pseudo-conditioning.
(2) To take GSR into adaptation for a vocal stimulus and other varbal activities.
(3) To train the subjects for conditioning the vocal stimulus.
(4) Finally to look into the conditioned generalization to see its effect on other controlled verbal activities.
For testing unconditioned stimulus, an electric shock is used, as GSR can be noticed thereby in diagram. S's spoken word as a conditioned. stimulus is a non-sense word, such as‘VOLVAP’adopted in the Noble's experimental process. Verbal activities used to test conditioned generalization cover six (6) experimental cases, in which the subject is to (1) whisper, (2) subvocally speak, (3) image (4) look at the letters : ‘VOL-VAP’, (5) listen and (6) read the same non-sense word. Another non-sense word :‘NOSTAW’, is also used for the same purpose in the abovementioned last three verbal activity tests. Other details in procedure are similar to those in Noble's experiment.
Results : As Ss had not shown evidence for pseudo-conditioning and reached the level in adaptation in stage (2), they were subjected to train for conditioning, with the results that all of them gave CR's to a temporal stimulus compound, consisting of a light followed by S's self-initiated vocal response, as given in the form of the aforesaid non-sense word. In testing the conditioned generalization, it was found that GSR's were subsequently generalized to self-initiated verbal stimulus, as in the 1st, 2nd and 3rd cases in respose to the visual cue, and that the amplitude date for response to light alone indicated a certain differentiation in the self-initiated vocal stimulus condition. Furthermore, GSR's were generalized to stimulus in the 4th and 6th cases (look at and read ‘VOLVAP’ respectively), but no similar indication was given in the 5th case (listen to the same none-sense word). However, in the test on‘NOSTAW’non of similar results was obtained.
Discussion : From the above test data, it can be concluded that the self-initiated vocal stimulus becomes the ‘sign’ representing electric shock as US, in which ‘signvehicle’ can be taken as an auditorial stimulus on else as a proprioceptive stimulus by the related muscle's movement. From these findings as to the degrees of several conditioned generalizations on verbal activities, it can also. be determined that the dominant factor referred to is not an auditorial stimulus, but a certain proprioceptive stimulus that is involved. Since the different word‘NOSTAW’was cleariy discriminated from ‘VOLVAP’, it is particularly emphasized that a ‘sign’- object is more important than the ‘sign-vehide’ in this conditioning process.

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In experiments on rigidity, Ss learn one set of responses and then are required to shift to another set of responses. Rigidity is defined in terms of failure to make such a shift. There are several different types of shifts. Buss A. H. found that, compared with reversal shift, which involved a reversal of positive and negative cues, nonreversal shift, which involved a change in the stimulus dimension, retarded the subsequent learning. He explained that in the learning of subsequent discrimination, nonreveral shift had fortuitous partial reinforcement of the set that had been learned previously.
To confirm this Buss's explanation, we investigated the effects of one reversal shift and three non-reversal shifts upon learning of subsequent discrimination. Four groups of Ss learned two series of discrimination problems. Ss were presented with two stimuli simultaneously, and were required to choose one of theme.
One group learned a size discrimination in Series 1 and the reversed size discrimination in Series 2 (reversal shift). Another three groups learned a size discrimination in Series 1 and a form discrimination in Series 2 (non-reversal shift). In Series 2. these three groups differed from each other in regard to the possibility of fortuitous partial reinforcement of size discrimination learned previously. Values of such possibility for the three groups were 25%, 50% and 75%, respectively. If Buss's account is right, we should be able to predict that the learning of Series 2 will be more difficult in proportion to the degree of such possibility in Series 2.
Our results confirmed the prediction. The actual percentages of partial reinforcement in Series 2 were 0% (reversal shift), 15.3%, 33.2%, and 65.0%, respectively. Learning of Series 2 was the easiest in reversal shift, and was more difficult in proportion to the percentage of partial reinforcement.

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