Importance of crack-propagation-induced ε-martensite in strain-controlled low-cycle fatigue of high-Mn austenitic steel

We investigated the roles of deformation-induced ε-martensitic transformation on strain-controlled low-cycle fatigue (LCF) through crack-propagation analysis involving a notching technique that used a focused ion beam (FIB) setup on Fe–30Mn–4Si–2Al austenitic steel. Using the FIB notch, we separated the microstructure evolution into macroscopic cyclic deformation-induced and crack-propagation-induced microstructures. Following this, we clarified the fatigue crack-propagation-induced ε-martensitic transformation to decelerate crack propagation at a total strain range of 2%, obtaining an extraordinary LCF life of 1.1 × 10⁴ cycles.     

Mantle region accommodating two-dimensional grain boundary sliding in ODS ferritic steel

Two-dimensional grain-boundary sliding (GBS) was achieved microscopically in an oxide-dispersion-strengthened ferritic steel with an elongated and aligned grain structure, which was deformed perpendicular to the long axis. At the border between superplastic regions II and III, microscopic deformation was observed using sub-micron grids drawn on the material surface using a focused ion beam. GBS was accommodated by intragranular deformations in narrow areas around grain boundaries, which has been predicted by earlier researchers as characteristics of the core–mantle model. These observations suggest that dislocations slip only in the mantle regions around wavy boundaries to relax the stress concentration caused by GBS during superplasticity.     

Emergence of rhythm during motor learning

Complex motor skill often consists of a fixed sequence of movements. Recent studies show that a stereotyped temporal pattern or rhythm emerges as we learn to perform a motor sequence. This is because the sequence is reorganized during learning as serial chunks of movements in both a sequence-specific and subject-specific manner. On the basis of human imaging studies we propose that the formation of chunk patterns is controlled by the cerebellum, its posterior and anterior lobes contributing, respectively, to the temporal patterns before and after chunk formation. The motor rhythm can assist the motor networks in the cerebral cortex to control automatic movements within chunks and the cognitive networks to control non-automatic movements between chunks, respectively. In this way, organized motor skill can be performed automatically and flexibly.     

Influence of the role of a partner on anxiety due to a physically threatening situation

This study aimed to examine the influence of the presence of a partner in terms of affiliation level and role on anxiety in a physically threatening situation.

In the first experiment, nine male subjects waited alone for the electric shock, and the other nine subjects waited with their partner.

In the second experiment, 36 female subjects were assigned to four experimental groups by the difference of the role of a partner (coactor or audience) and the affiliation level of a partner (friend or stranger), and subjects waited for the electric shock with their partner.

It was found that anxiety of subjects decreased when the partner was a coactor and/or a friend. It was suggested that these two functioned differently in anxiety reduction in a physically threatening situation.     

Matching versus optimal data selection in the Wason selection task

It has been reported as a robust effect that people are likely to select a matching case in the Wason selection task. For example, they usually select the 5 case, in the Wason selection task with the conditional “if an E, then a not-5”. This was explained by the matching bias account that people are likely to regard a matching case as relevant to the truth of the conditional (Evans, 1998). However, because a positive concept usually constructs a smaller set than its negative one does (a rarity assumption), it is more effective to get information on the truth of the conditional in a positive set than in a negative set. Thus the optimal data selection account can also explain the effect. The set size of Q and matching by introducing negation were manipulated independently in four experiments. From the results it was inferred that the so-called matching bias was an amalgam of two different cognitive components—relevance judgement by matching and optimal data selection.     

Experts and laymen grossly underestimate the benefits of argumentation for reasoning

Many fields of study have shown that group discussion generally improves reasoning performance for a wide range of tasks. This article shows that most of the population, including specialists, does not expect group discussion to be as beneficial as it is. Six studies asked participants to solve a standard reasoning problem—the Wason selection task—and to estimate the performance of individuals working alone and in groups. We tested samples of U.S., Indian, and Japanese participants, European managers, and psychologists of reasoning. Every sample underestimated the improvement yielded by group discussion. They did so even after they had been explained the correct answer, or after they had had to solve the problem in groups. These mistaken intuitions could prevent individuals from making the best of institutions that rely on group discussion, from collaborative learning and work teams to deliberative assemblies.     

Social exclusion mediates the relationship between psychopathy and aggressive humor style in noninstitutionalized young adults

Previous research indicates a positive relationship between psychopathy and various negative humor styles. The purpose of the present study was to investigate social exclusion as a possible mediator of the association between psychopathy and negative humor styles in noninstitutionalized young adults. One hundred and thirty-nine university students participated by responding to questionnaires that assess psychopathy, the experience of exclusion from friends, and four humor styles (self-enhancing, affiliative, aggressive, and self-defeating). There was a significant positive association between psychopathy, social exclusion, and aggressive styles of humor, and a negative association between psychopathy and affiliative styles of humor. Moreover, the results of a mediation analysis indicated that the association between psychopathy and aggressive humor style is completely explained by the experience of social exclusion. These results suggest that high psychopathic participants who are socially excluded use an aggressive humor style more often than low psychopathic individuals. The present study provides further insights into the role played by social environmental factors in the links between psychopathy and associated interpersonal characteristics.     

Salivary conditioning with antennal gustatory unconditioned stimulus in an insect

Classical conditioning of olfactory conditioning stimulus (CS) with gustatory unconditioned stimulus (US) in insects has been used as a pertinent model for elucidation of neural mechanisms underlying learning and memory. However, a conditioning system in which stable intracellular recordings from brain neurons are feasibly obtained while monitoring the conditioning effect has remained to be established. Recently, we found classical conditioning of salivation in cockroaches Periplaneta americana, in which an odor was associated with sucrose solution applied to the mouth, and this conditioning could be monitored by activities of salivary neurons. Application of gustatory US to the mouth, however, leads to feeding movement accompanying a movement of the brain that prevents stable recordings from brain neurons. Here we investigated whether a gustatory stimulus presented to an antenna could serve as an effective US for producing salivary conditioning. Presentation of sucrose or sodium chloride solution to an antenna induced salivation and also increased activities of salivary neurons. A single pairing trial of an odor with antennal presentation of sucrose or sodium chloride solution produced conditioning of salivation or of activities of salivary neurons. Five pairing trials led to a conditioning effect that lasted for one day. Water or tactile stimulus presented to an antenna was not effective for producing conditioning. The results demonstrate that gustatory US presented to an antenna is as effective as that presented to the mouth for producing salivary conditioning. This conditioning system provides a useful model for studying the neural basis of learning at the level of singly identifiable neurons.