A series of experiments was conducted to find out whether initial turn alternation after the forced turn in Maze A (Fig. 1) is properly ascribed to thigmotropism, centrifugal swing, or inhibition factor when Ss were Armadillidium vulgare. It was found that (a) turn alternation is not affected by intertrial intervals, (b) it disappears when side-walls are eliminated, (c) a high degree of turn alternation is shown even when the alley immediately preceding the choice point is as long as 20 cm, and (d) spontaneous turn alternation between successive trials in the simple T maze or Maze B (Fig. 1) is always near and very often below 50% and independent of intertrial intervals.
It was concluded that the initial turn alternation phenomenon is due to thigmotropism rather than centrifugal swing, and probably not to inhibition factor such as reactive inhibition and stimulus satiation. A number of points are suggested for further research.

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Three groups of 18 albino rats each were given twenty successive freechoice trials per day for seven days, i. e., a conditioning period, in a semicircular maze which had eight equal goalboxes. The following day was an extinction period of sixty trials. The groups differed with respect to the period in which they received the emotional stimuli. Group EC received them immediately before each of the last five days of the conditioning period, and Group EE was given immediately before the extinction period. Group C did not receive them during all periods.
The emotional stimuli consisted of three different components; i. e., the electric shock through a grid, the bright light and the loud sound, which simultaneously given for ten seconds at intervals of five seconds during five minutes at a small pen-box placed in another room.
In Group EC the emotional stimuli gradually decreased behavior variability until the 5th or 6th day of the conditioning period. Differences in behavior variability between Group EC and Group C during the last five days of conditioning were statistically significant. Although Group C indicated a progressive decrement of behavior variability in extinction, the decremental effect of the emotinal stimuli on behavior variability was found at the later stage of extinction in Group EE. But jumping responses in Group EE increased from the early stage of the extinction period. In the previous experiment and in Group C, it was found that these jumping responses were characteristic of the later stage of extinction. So the emotional stimuli given before extinction might facilitate an appearance of some emotional aspects which ordinarily occurred at the later stage of extinction.

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Auditory thresholds of animals have been measured all by the conditioning methods.
In 1936, NEET, C. reported that the verbal report yielded lower auditory discrimination threshold than the conditioned response. In 1937, HOVLAND, C. reported the similar results.
The writer investigated whether the spontaneous activity level could be used as an index to determine the upper and the lower auditory thresholds of the white rat. The general activity decreased on the presentation of auditory stimuli. It was assumed that the auditory stimulus was perceived by the rat when the general activity decreased on presentation of an auditory stimulus.
The upper and lower auditory thresholds of the white rat were determined using the general activity as an index. The upper one was estimated within the range of 18, 000 and 19, 000 cps and the lower one was within 40 to 30 cps.
The results were compared with these obtained by the method of avoidance learning to examine the hypothesis mentioned above. It was found out that both results are almost the same.

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The purpose of the present experiment was to study the acute and chronic effects of methamphetamine hydrochloride on the spontaneous activity in rats.
The Ss were ten male albino rats, aged about three months at the beginning of the experiment. The battery of ten activity wheels and the open field apparatus were used. Each wheel with a small living cage located in a sound-proof box, was always illuminated by a 10 watt lamp throughout the experiment. The temperature in the box averaged 20°C with a range of 19° to 23°C. The activity wheel have been described in detail previously (Annual of Animal Psychol., 11, 1962). The open field apparatus consisted of a circular floor 100 cm in diameter having a enclosing wall 40 cm in height. The grey circular floor was divided into 32 sections equal in area by drawing three concentric circles and four diameter lines with black color paint. Each S was put at the center of the floor just 30 min later since the administration of drug, and permitted to explore the open field for 3 min per day.
The procedures and the main results of wheel-activity were as follows. The Ss were first given a 15-day habituation period in the activity wheel. Food and water were always available, replenished at 2 : 00 P. M. There followed a 5-day period during which a 3mg/kg dose of methamphetamine was subcutaneously injected every day at 2 : 00 P. M. This administration of drug produced a marked increase in activity which lasted for about four hours after injection. After the next non-injection period (5 days), there followed a 35-day period during which the Ss were given a daily injection of 6mg/kg of methamphetamine. The injection of a 6mg/kg dose first produced a striking decrease in activity for about one hour, but thereafter, showing the gradual increase in activity, it instigated the activity to the level which was higher than that of a 3mg/kg dose. And then, the rats were returned to the non-injection condition for next 55 days. It was surprising that under such a condition the marked decrease in activity was observed. The long-lasting inactivity thus obtained might be regarded as due to the chronic effect of repeated doses. The next 25 days constituted a 23-hr food deprivation period, i. e. during these days the food dishes were removed each day at 2 : 00 P. M. and returned on the following day at 1 : 00 P. M. It was shown that the level of activity gradually increased and the most clear-cut increase was in the activity during the two hours just preceding the daily feeding. Finally, the feeding condition was shifted from the 23-hr food deprivation to the ad libitum feeding. The level of activity under the condition of ad libitum feeding (for 10 days) declined again to the level shown during the habituation period. From these results it could not be concluded that the introduction of hunger drive produced by a 23-hr food deprivation had the permanent disinhibiting effect on the depressive state resulted from the chronic methamphetamine intoxication. Further studies will be required to reveal whether the disinhibiting effect is temporal or permanent.
The results of the open field test were parallel to that of the activity wheel mentioned above except that the locomotive activity in intoxicated rats increased to the normal level immediately after the cessetion of long lasting administration of methamphetamine (6mg/kg). It would seem that this increase is not due to the recovery from the drug intoxication, but due in part to the increment of reactivity in animals to the change of external stimulus situation.

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Chronic administration of methamphetamine hydrochloride (MA-HCl, philopon) has a marked ability to produce a reduction in activity. However, it would appear strange that such a psychic stimulant as methamphetamine has an effect like this. Dr. UTENA et al (2) and Dr. YAGI (11) also has clearly shown that a reduction of spontaneity lasts as long as two months after the cessation of chronic administration made for about a month. Dr. UTENA explained comprehensively that inactivity produced by chronic administration of methamphetamine is very similar to a reduction of spontaneity which is certainly one of the essential symptoms of psychotic patients from the view point of experimental psychopathology. This effect was called an after-depression by Dr. UTENA and in our experiment the after-depression was studied from the view point of experimental psychology.
Methods : 21 male albino rats, aged about 150 days at the end of the experiment, were used and they were divided into three groups, namely a control group, a MA · avoidance group, and a MA-avoidance group.
1. In the control group, rats were not given methamphetamine and were tested by the method of avoidance learning.
2. In the MA · avoidance group, rats were tested by the method of avoidance learning on the 36th day after every 35 days of daily injection of methamphetamine (6 mg/kg/a day, dissolved by 2cc saline, given subcutaneously).
3. In the MA-avoidance group, rats were tested by the method of avoidance learning on the 66th day : after 35 days' injections which are the same procedures as in the case of the MA · avoidance group and the 30 days' period of rest in each home cage.
Results and conclusions : As it would be seen in Table 1, avoidance learning was more difficult in the MA·avoidance group and the MA-avoidance group than in the control group. It is interpreted as chronic administration of MA-HCl makes rats dull.
It is a well known fact that fast extinction succeeds slow learning because discrimination between them becomes easy, and this fact is clearly shown in Table 1 also. However, both of the experimental groups did not show fast extinction and showed slower extinction than did the control group. It is interpreted as chronic administration of MA-HCl makes rats fearful.
The present findings mentioned above are due to the adapted mechanisms for the chronic chemical stimulation, that is, a set of metabolic changes in the brain tissues as observed by Dr. UTENA, but not to the loss of motor ability because difference between the control group and the two experimental groups was not seen in running times at the first trials and the last trials of learning.

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