The procerebrum is necessary for odor-aversion learning in the terrestrial slug Limax valentianus

The terrestrial slug Limax has a highly developed ability to associate the odor of some foods (e.g., carrot juice) with aversive stimuli such as the bitter taste of quinidine solution. The procerebrum (PC) is a part of the slug's brain thought to be involved in odor-aversion learning, but direct evidence is still lacking. Here we present evidence showing that the PC is essential for odor-aversion learning. Unlike sham-operated slugs, PC ablation 7 d prior to conditioning showed that most slugs did not avoid carrot juice in the memory retention test conducted 24 h after the conditioning. Slugs with the PC ablated 3 h, 1 d, 3 d, or 7 d after conditioning and examined by the memory retention test at 3 d after the PC ablation were also less likely to avoid carrot juice than sham-operated slugs. The PC ablation did not damage the ability of the slugs to sense attractive odor (everyday food) or innately aversive odor (onion or garlic). These results demonstrate that the PC is a necessary component in the retention and/or retrieval of odor-aversion memory.     

Depletion of serotonin selectively impairs short-term memory without affecting long-term memory in odor learning in the terrestrial slug Limax valentianus

The terrestrial slug Limax is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory. HPLC (high-performance liquid chromatography) analysis revealed that 5,7-DHT significantly reduced serotonin content in the central nervous system. The present study suggests that acquisition, retention, and/or retrieval of short-term memory involves serotonin, and neither acquisition nor retrieval of long-term memory requires serotonin at a level as high as that required for short-term memory.     

Validation study on self-reported height, weight, and blood pressure

Self-report data were compared with actual recorded data on height, weight, and blood pressure during health examinations to check for validity. The subjects were 1,823 persons, ages 40-68 years. Pearson correlations for systolic blood pressure, diastolic blood pressure, height, weight, and Body Mass Index between data reported in 1993 and measurements made in 1991 were .63, .60, .96, .96, and .92, respectively. Pearson correlations for the same variables between the data reported in 1993 and the measurements made in 1992 were .73, .67, .97, .97, and .94, respectively. Self-reported values for height, weight, and Body Mass Index appear to be valid over years or so.     

Task-dependent changes of the psychophysical motion-tuning functions in the course of perceptual learning

In some cases, perceptual learning is task-specific. However, task-dependent effects of perceptual learning on psychophysical motion-tuning functions have yet to be clarified. In the present study, subjects performed motion detection or discrimination of the same stimulus over the course of four sessions held on separate days. Subjects who performed motion detection showed the most highly improved performance on the trained motion directions. However, after discrimination training, the highest improvement was not observed at the trained directions but shifted away from them. These results can be explained by lateral inhibition. Task demands may differentially modulate excitatory and inhibitory signals to directions in the vicinity of the trained directions.     

Discrimination of “Four” and “Two” by Pigeons

The Psychological Record - Two pigeons learned to respond to four objects while withholding response to two objects. The birds maintained their numerical discrimination when new objects were...     

Difficulties in amae: A clinical perspective

The Japanese word amae refers initially to the infant's feelings and attachment behavior toward the mother. Doi has vividly described how amae is carried through into adulthood characterizing Japanese social and family relationships and Japanese psychology. Exploring implications of the amae concept for infant research will be helped by including other aspects of amae manifest in clinical work: (1) Amae takes place in the complex vicissitudes of motherhood in Japan in which the mother fulfills her social as well as emotional needs through her infant; (2) as the child grows older he or she learns that amae can only be fulfilled if he or she is able to meet the parent's and the social demand for achievement; (3) there is a long tradition of inhibition of amae among women which is passed on from generation to generation affecting the quality of mothering; (4) the intuitive aspect of good enough amae in the parent-in-fant relationship is being lost due to rapid ongoing social changes. Therapeutic endeavors to retrieve the intuitive aspect of amae prove effective for the increasing numbers of relationship disturbances in infancy.     

The study of early emotion processing in the frontal area using a two-dipole source model

The present study explored early emotion processing in the frontal area using the two-dipole source model. The 21-channel recordings of event-related potentials (ERPs) produced by a pure tone were analyzed in order to assess information processing. In the test conditions, the pure tone followed the presentation of one of two unpleasant sounds to enhance anxiety. In the control condition, only the pure tone was presented. There were two groups of eight subjects, one with low scores for trait anxiety and one with high scores. The ERPs were separately averaged for the groups, as well as for the high- and low-anxiety sound and control session. A negative peak around 120 ms (C2) and a positive peak around 280 ms (C5) after stimulus onset were identified in all the sessions. The two-dipole source model was applied to these two components. In the C2 component, dipole sources were located in the left frontal area in the control sessions, and in the right frontal area in the high-anxiety sessions. This activation pattern was clearer in the group with low trait anxiety. In contrast, with the C5 component, lateralization of the dipole source in the frontal area was not seen. These findings suggest that the frontal area is involved in early emotion processing. A dual-stage model of emotion processing is therefore proposed.