The present experiment was designed to investigate the retention and relearning upon mult FR DRL and mult FR DRO schedule in rats with septal lesions.
After thirteen days acquisition of mult FR10 DRL8, mult FR10 DRL20, mult FR10 DRO8, or mult FR10 DRO20 for food reinforcement, half of the rats received septal lesions and the other half received sham operations in each group. All of them were trained again on the same schedule as those of acquisition sessions for fourteen days after surgical operations. Using these procedures, every session was composed of the same three replications having a three min FR component, one min time out, and a seven min DRL or DRO component respectively. The reinforcer was a forty five mg pellet. The each experimental group was consisted of two animals in the relearning. In the case of septal lesions the electrode was lowered 2.0 mm anterior to bregma on the midline, 6.5mm below the surface of the skull, and 2. 0ma dc was passed for 30 secI. n the case of sham operations the electrode was lowered 2.0mm anterior to bregma on the midline, 3.5mm below the surface of the skull, no current was passed for 30 sec.
The main findings were as follows. There were no significant differences in the number of lever press responses on FR component between septal and sham rats throughout the relearning. The efficiency ratio (reinforcements/responses) was lower in septal rats than in sham throughout the relearning (Fig. 2). The IRT distributions on DRL8 component showed that the responding of septalr ats as well as sham was suppressed by a particular class of IRTs.
The septal area seems to be concerned with the withholding of operant responses on the DRL20 schedule which is more difficult to learn than the DRL8. The behavioral impairments of animals with septal lesions on DRL schedule may depend upon the DRL time. The septal area does not concern with the successive discrimination task which is required to differentiate the rate of operant responses for the corresponding component.

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魚類では多数の卵がまとめて産み出される。このような条件下でふ化した仔魚がいつ頃から自ら群れをつくる性質を示し, どのように発達していくのか, そして, その発達に外部要因としての仲間との接触経験がどう影響しているのかという問題は, 群泳行動の機構を理解する上で一つの課題である。
メダカ (Oryzias latipes) の群泳行動についてはすでにいくつかの報告 (1, 2) があるが, 本研究では, 群泳行動を, 視覚のみによる誘引性と, すべての感覚が許される自由遊泳下での群泳度の2つの段階に分けて観察し, 仲間との接触を通しての経験が, どの段階に, どのように影響しているのかを隔離飼育実験によって調べた。
ヒメダカの群泳行動の発達において, 仲間との接触経験がどのように作用しているのかを明らかにする目的で, 隔離飼育の影響を調べた。群泳行動の発達を, 透明な仕切りを隔てた視覚による誘引性 (実験1) と, 1つの容器内での自由遊泳下の群泳度 (実験2) の2つに分けて実験を行なった。結果は以下の通りである。
1) 集団飼育魚及び隔離飼育魚ともに全長8-9mm (ふ化後30日) になると視覚による誘引性が現われ, その後成長とともに徐々に強くなる傾向がみられた。2) 隔離飼育魚の方が成長段階を通して全体に誘引性は強い傾向にあった。3) 自由遊泳の条件下では, 群れの集中度は成長につれ直線的に大きくなり, 全長12-14mmを越えると個体の空間分布は統計的には集中分布を示した。これらの点では集団飼育魚と隔離飼育魚には差はなかった。4) しかし, 細かい運動パターンには差がみられ, 全長20mm (ふ化後90日) の段階で, 隔離飼育魚では群泳中の動きの中に未発達の部分が残されていた。
以上の結果は, 群泳行動の発達には, 一方で, 視覚による誘引性の遺伝的発達機構があり, 他方で, 成長過程において仲間の遊泳運動に起因する水の動きを受容する経験が必要とされ, それを経て群泳行動が完成されていくことを示している。

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The experiment was designed to investigate the effect of positions of correct stimulus on oddity learning process by Japanese monkeys.
After preliminary training, nine Japanese monkeys were given three-position oddity problems with a simple test apparatus (Fig. 1). Subjects were devided into three groups : three to Group (C), which received color oddity problems, and three to Group (F), which received form oddity problems, then, htree to Group (S), which received size oddity problems.
Four kinds of stimuli were used respectively (Fig. 2). They were different from each other only in the relevant dimension. Combinations and permurations of four stimuli provided 36 different spatial configurations, which were randomly presented twice a day (72 trials a day). A noncorrection method was used. After criterion (more than 80% correct responses, two successive days) had been attained, monkeys were subjected to transfer test. Transfer effect was observed.
The results were as follows;
(1) The learning was accomplished in from 432 trials to 1008 trials (Table 1). There was individual difference. But there was no difference among the three groups. Percentage of correct choices throughout the oddity learning was not different among the three groups, either.
(2) With respect to the percentage of correct responses in the center position, there existed three stages definitely : first, monkeys made more choices of the center stimulus and made more correct responses there; second, their choices of the center stimulus decreased and correct responses in this position also decreased near or below the chance level (33.3%); third, the correct responses in the center position rapidly increased (Fig. 3, Fig. 4, Fig. 5). There was a monkey (S-3) which did not represent this st ages.
It was suggested that there were three stages of oddity learning process by Japanese monkeys; (i) monkeys hypothetically made many choices of the center stimulus, and at next stage, (ii) they learned the correct response when odd stimulus was on left or right side, and then, (iii) they learned the corret response when the correct stimulus was in the center, additionaly.

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