NK(3) receptor agonism promotes episodic-like memory in mice

The mammalian tachykinins are a family of closely related peptides including substance P, neurokinin A, neurokinin B and, recently, also hemokinin-1. They are present in the peripheral and central nervous systems, and bind to three known neurokinin (NK) receptors, the NK(1)-, NK(2)- and NK(3) receptors. In both rodents and humans, NK(3) receptors are expressed in brain structures which have been associated with learning and memory. Evidence for a role of NK(3) receptors in learning and memory has been found in NK(3) receptor knockout mice. Here, we investigated the influence of the NK(3) receptor agonist, senktide (0.1, 0.2 and 0.4 mg/kg), on the performance of C57BL/6 mice in a recently developed episodic-like memory task. Since a promnestic effect of senktide was expected, we employed an experimental protocol that provided sub-optimal learning conditions for episodic-like memory. The results indicate that senktide promotes episodic-like memory in mice in a dose-dependent manner, providing, for the first time, evidence for an involvement of NK(3) receptors in episodic-like memory.     

Body expressions influence recognition of emotions in the face and voice

The most familiar emotional signals consist of faces, voices, and whole-body expressions, but so far research on emotions expressed by the whole body is sparse. The authors investigated recognition of whole-body expressions of emotion in three experiments. In the first experiment, participants performed a body expression-matching task. Results indicate good recognition of all emotions, with fear being the hardest to recognize. In the second experiment, two alternative forced choice categorizations of the facial expression of a compound face-body stimulus were strongly influenced by the bodily expression. This effect was a function of the ambiguity of the facial expression. In the third experiment, recognition of emotional tone of voice was similarly influenced by task irrelevant emotional body expressions. Taken together, the findings illustrate the importance of emotional whole-body expressions in communication either when viewed on their own or, as is often the case in realistic circumstances, in combination with facial expressions and emotional voices.     

The association between life events and suicide intent in self-poisoners with and without a history of deliberate self-harm: a preliminary study

The associations between life events in the 12 months preceding an episode of self-poisoning resulting in hospital attendance (the index episode), and the suicide intent of this episode were compared in individuals for whom the index episode was their first, episode and in individuals in whom it was a recurrence of DSH. Results indicated a significant interaction between independent life events, repetition status, and gender in the prediction of suicide intent, the association between life events and intent being moderated by repetition status in women only. The results provide preliminary evidence to suggest the presence of a suicidal process in women, in which the impact of negative life events on suicide intent diminishes across episodes.     

Criticizing groups from the inside and the outside: an identity perspective on the intergroup sensitivity effect

Research on group criticism has demonstrated that criticisms are received less defensively when made by an ingroup member than when made by an outsider (the intergroup sensitivity effect). Three experiments tested the extent to which this effect is driven by social identity concerns or by judgments of how experienced the source of the criticism is. In Experiments 1 and 2, Australians who criticized Australia (ingroup critics) were met with less defensiveness than were foreigners who criticized Australia (outgroup critics), regardless of the amount of experience the foreigner had with Australia. Furthermore, the effects of speaker type on evaluations were mediated by perceptions of the extent to which the criticisms were intended to be constructive but not by perceptions of experience. Finally, Experiment 3 indicated that although experience does not help outgroup critics, a lack of experience can hurt ingroup critics. Recommendations are provided as to how people can reduce defensiveness when making group criticisms.     

A short history of ideo-motor action

The ideo-motor theory, which is currently receiving heightened interest in cognitive psychology, looks back on a long history. Essentially two historical roots can be presented. A British one, initiated by Laycock (1845) and Carpenter (1852), which was developed in order to explain ideo-motor phenomena by means of cerebral reflex actions. A second and older root is the German one by Herbart (1816, 1825), Lotze (1852), and Harless (1861), which considered the ideo-motor principle a fundamental mechanism of all intentional human behaviour. Both roots converged in James' (1890) Principles of Psychology before they fell into oblivion due to the dominance of behaviorism in the first half of the 20th century. The few empirical ideo-motor studies of the early 20th century are briefly described. Finally, similarities and differences in the history of the ideo-motor theory are delineated and a perspective is given covering research questions that could be examined in the future.     

Why people engage in parasuicide: a cross-cultural study of intentions

Information obtained at interview from 1,646 parasuicide patients in 14 regions in 13 European countries participating in the WHO/EURO Multicentre Study on Suicidal Behaviour was used to study self-reported intentions involved in parasuicide. Comparisons were made across cultures, genders, and age groups. Although some statistically significant differences were found, the effect sizes were very small. The main finding from this study is thus that parasuicide patients in different countries tend to indicate that similar types of intentions are involved in their acts of parasuicide, and that the intentions do not vary greatly with gender or age. The hypothesis that rates of suicide and parasuicide vary between regions with the frequency with which suicidal intention is indicated by the patients was also tested, but was supported only for women and in relation to national suicide rates. The findings from this study are likely to be generalizable to other settings and have implications for clinical practice.     

On the role of item similarity in retrieval-induced forgetting

We report on two experiments designed to examine how the similarity of retrieval-practised and not-retrieval-practised items influences the amount of retrieval-induced forgetting. Participants studied categorised item lists with each category consisting of exemplars from two different semantic subcategories. Using both the retrieval practice paradigm (Experiment 1) and the output interference paradigm (Experiment 2) we found that the retrieval of a subset of the studied items impaired the subsequent recall of the nonpractised items if the two types of items were fairly dissimilar to each other (same category but different subcategory) but did not induce impairment if the two types of items were highly similar (same category and subcategory). These results indicate that a high degree of similarity of practised and nonpractised items can eliminate retrieval-induced forgetting. They also suggest that forgetting in the retrieval practice paradigm and forgetting in the output interference paradigm are mediated by the same mechanisms. The relation of the present results to other very recent findings about the role of item similarity in retrieval-induced forgetting in discussed.     

Content‐specific gender differences in emotion ratings from early to late adulthood

The investigation of gender differences in emotion has attracted much attention given the potential ramifications on our understanding of sexual differences in disorders involving emotion dysregulation. Yet, research on content‐specific gender differences across adulthood in emotional responding is lacking. The aims of the present study were twofold. First, we sought to investigate to what extent gender differences in the self‐reported emotional experience are content specific. Second, we sought to determine whether gender differences are stable across the adult lifespan. We assessed valence and arousal ratings of 14 picture series, each of a different content, in 94 men and 118 women aged 20 to 81. Compared to women, men reacted more positively to erotic images, whereas women rated low‐arousing pleasant family scenes and landscapes as particularly positive. Women displayed a disposition to respond with greater defensive activation (i.e., more negative valence and higher arousal), in particular to the most arousing unpleasant contents. Importantly, significant interactions between gender and age were not found for any single content. This study makes a novel contribution by showing that gender differences in the affective experiences in response to different contents persist across the adult lifespan. These findings support the “stability hypothesis” of gender differences across age.     

Intentional fixation of behavioural learning,or how R-O learning blocks S-R learning

Four experiments deal with the acquisition of knowledge for the control of voluntary behaviour. Subjects had to accomplish a computer-controlled learning task that required them to learn which one of four actions (R) had to be performed in order to attain a certain one of four outcomes (O) in the presence of one of four situational contexts (S). Reinforcements were assigned to actions according to two schedules: In the S-R condition each of the four actions was consistently reinforced in the presence of a certain situation, whereas in the R-O condition each of the actions was either always (Experiments 1-3) or mostly (Experiment 4) reinforced if a certain outcome was required. Furthermore, the type of feedback was varied. In Experiment 1, only positive or negative reinforcements were fed back, whereas in Experiments 2-4 the actions resulted in outcomes that had to be compared with the required outcomes in order to determine successes and failures. The results indicate a preference for learning R-O contingencies over learning S-R contingencies. Most subjects were so fixated on learning R-O relations that they remained completely blind to the consistent reinforcement of S-R mappings. The data suggest that, in line with the ideomotor principle, the acquisition of behavioural competence is based primarily on the formation of bidirectional action-outcome relations. Specifications of the underlying learning mechanisms are discussed.