Two Japanese monkeys were trained on a higher-order conditional discrimination task with two colors (red and purple) which consisted of a matching-to-sample and an oddity-from-sample discrimination. External stimuli (patterns on a key, etc.) served as conditional discriminative stimuli for matching and oddity. Both subjects mastered this complex task. Then, the stimulus control established in the training was examined with test trials inserted among baseline trials. Subjects correctly responded on the test trials in which the incorrect comparison stimulus specified by the sample was no longer presented. However, subjects could not respond correctly when both sample and comparison stimuli were replaced with two new colors (yellow and yellowgreen). Thus, no evidence that the identity-difference relation of stimuli controlled the subjects' responding was obtained even in the presence of the higher-order conditional discriminative stimuli controlling their matching and oddity responses. These results suggested that the specific relation between the sample and the correct comparison stimulus mainly controlled two-color matching and oddity behaviors of Japanese monkeys.

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Rats received shock that was predicted by either a light signal alone, light-tone complex signal or no signal. In the light signal alone and light-tone complex signal conditions, experimental rats which could avoid and/or escape shock developed less gastric ulceration than did yoked “helpless” rats which had exactly the same shock but had no control over shock. In the non-signal condition, however, the experimental rats did not differ from the matched yoked rats. Ulceration of non-shock control rats was negligible as compared to experimental and yoked rats in each of the three warning conditions. Presence or absence of a safety signal has an effect on ulcerogenesis. The light signal alone condition was effective in reducing ulceration for “helpless” rats as well as rats which could control shock. Thus, the effectiveness of a coping behavior depends on the reliable prediction of shock in a stressful situation.

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In order to explain the process of responsibility judgments for an automobile accident, the estimates of self-based consensus (i.e., would I have behaved as the motorist did?) and sample-based consensus (i. e., would ordinary people have behaved as the motorist did?) were introduced as mediational variables. As expected, for all three accident situations utilized in the present study, the extent of responsibility attributed to the motorist was found to be negatively correlated with both self-based and sample-based consensus estimates, and a highly positive correlation was observed between these two types of consensus estimates. In addition, a consistent tendency of differences emerged when subjects were divided into two groups on the basis of whether or not they had a driver's license, in that driver subjects generated lower consensus estimates and attributed greater responsibility to the accident perpetrator than did nondriver subjects. Implications of these results for the issue of self-protective motivational biases were discussed, together with the conceptual issue of responsibility which was addressed to in the present study by incorporation of test-retest procedure and by inclusion of sanction measures.

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The accuracy of the discrimination of the length of two parallel line segments by 19 to 33 month old children was investigated. The child's task was to put a rod into the longer groove of the two stimulus boards presented simultaneously in various spatial arrangements. Main results were as follows: The children could learn to discriminate the line length, and the Weber's ratio in the optimal condition was about. 18. The accuracy of the discrimination improved with age, and was influenced by the various spatial arrangements of the stimuli. To explain these results, a mental transformation framework was suggested, whereby the discrimination of line length was performed by a mental superposition of line segments. That is, when two parallel line segments were superposed by the parallel translation in the representational space, the translation being analyzed into the vector of the direction along the lines and the vector of the direction perpendicular to them, the accuracy of the discrimination of the length was almost prescribed by the norm of the former vector.

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Rats were implanted a electrode into the lateral hypothalamus for self-stimulation (SS) and a cannula into the lateral ventricle ipsilaterally for drug treatment. After stable SS was established, each rat was injected 6-OHDA (10 μg/5 Ill/injection) or 6-OHDA (same dosage) with desmethylimipramine (DMI)-pretreatment on 10 consecutive days through the implanted cannula. 6-OHDA treated rats showed gradual decrease in SS rate as daily SS testings proceeded, whereas DMI+6-OHDA treated rats showed no significant changes in SS rates through the entire course of testing except on the first day of drug administration. The degree of catecholamine depletion was assessed by a biochemical fluorescent method using yoked rats of each group. 6-OHDA caused a significant depletion of NE content in the cortex and the hypothalamus, whereas DMI+6-OHDA decreased DA contents significantly in the cortex and the caudatus. The obtained results for changes in SS rates in the two groups were discussed in terms of Herberg et al. s hypothesis that in SS, DA and NE played complementary roles by being involved in the motivation and reinforcement.

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The present study was designed to clarify whether and how helping behavior under negative feelings would be motivated by the desire to compensate negative feelings. The main findings were as follows: In Experiment I, the subjects in positive experience condition helped significantly faster than the subjects in negative experience condition. In Experiment II, the rate of acceptance of the request for help varied according to the amount of the cost of helping in the positive experience condition. In the negative experience condition, however, the rate of acceptance was not influenced by the amount of the cost. In particular, the request for help with high cost was not always refused. From these results it was inferred that the helping behavior under negative feelings would be motivated by the desire to avoid further self-image reduction caused by refusing a request for help.

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An apparatus, named KGbox-24, which enabled one to measure rat's eating, drinking, rearing and locomotive activities over 24 h a day was introduced. The effects upon these behaviors of shocks given at 2100 hours, or at one hour after the beginning of the 12-h dark phase, were studied over 10 days, with a single rat. Using the results of this rat for an illustrative purpose, the methods to analyze both the local and overall effects of shocks and to quantify the patterns of behaviors over a wide range of time were introduced. There was evidence of a development of conditioned suppression of eating and drinking during the first hour of the dark phase. The suppressing effects of 2100 hours shocks upon eating and drinking also gradually spreaded bidirectionally along the temporal dimension from 2100 hours. Although the factual aspects of the present study have to be ascertained in future, the present apparatus and the analysis-methods seem to be promising for the future studies of rat's adaptive processes in an aversive situation.

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