Visual discrimination of normal and drug induced behavior in quails (<Emphasis Type="Italic">Coturnix coturnix japonica</Emphasis>)

The ability to discriminate the physical states of others could be an adaptive behavior, especially for social animals. For example, the ability to discriminate illness behavior would be helpful for avoiding spoiled foods. We report on an experiment with Japanese quails testing whether these birds can discriminate the physical states of conspecifics. The quails were trained to discriminate between moving video images of quails injected with psychoactive drugs and those in a normal (not injected) condition. Methamphetamine (stimulant) or ketamine (anesthetic) were used to produce drug-induced behaviors in conspecifics. The former induced hyperactive behavior and the latter hypoactive behavior. The subject quails could learn the discrimination and showed generalization to novel images of the drug-induced behaviors. They did not, however, show discriminative behavior according to the type and dosage of the drugs. Thus, they categorized the behavior not on the basis of degree of activity, but on the basis of abnormality.     

Effect of the COMT Val158Met genotype on lateral prefrontal activations in young children

Low executive function (EF) during early childhood is a major risk factor for developmental delay, academic failure, and social withdrawal. Susceptible genes may affect the molecular and biological mechanisms underpinning EF. More specifically, genes associated with the regulation of prefrontal dopamine may modulate the response of prefrontal neurons during executive control. Several studies with adults and older children have shown that variants of the catechol‐O‐methyltransferase (COMT) gene are associated with behavioral performance and prefrontal activations in EF tasks. However, the effect of the COMT genotype on prefrontal activations during EF tasks on young children is still unknown. The present study examined whether a common functional polymorphism (Val158Met) in the COMT gene was associated with prefrontal activations and cognitive shifting in 3‐ to 6‐year‐old children. The study revealed that, compared with children with at least one Met allele (Met/Met and Met/Val), children who were Val homozygous (i) were more able to flexibly switch rules in cognitive shifting tasks and (ii) exhibited increased activations in lateral prefrontal regions during these tasks. This is the first evidence that demonstrates the relationship between a gene polymorphism and prefrontal activations in young children. It also indicates that COMT Val homozygosity may be advantageous for cognitive shifting and prefrontal functions, at least during early childhood, and children who possess this variant may have a lower risk of developing future cognitive and social development issues.     

Dual frames for causal induction: the normative and the heuristic

Causal induction in the real world often has to be quick and efficient as well as accurate. We propose that people use two different frames to achieve these goals. The A-frame consists of heuristic processes that presuppose rarity and can detect causally relevant factors quickly. The B-frame consists of analytic processes that can be highly accurate in detecting actual causes. Our dual frame theory implies that several factors affect whether people use the A-frame or the B-frame in causal induction: among these are symmetrical negation, intervention and commitment. This theory is tested and sustained in two experiments. The results also provide broad support for dual process accounts of human thinking in general.     

Prevalence of maladaptive behavior in retarded children as a function of IQ and age

One hundred and twentyeight mentally retarded children, ages 6 to 14, from a special school were assessed by teachers in terms of nine maladaptive behaviors. The results indicated that the prevalence of some maladaptive behaviors changed as a function of IQ and age, and that there were splits of such changes as IQ-dependent and as age-dependent by maladaptive behavior.     

A single bout of resistance exercise can enhance episodic memory performance

Acute aerobic exercise can be beneficial to episodic memory. This benefit may occur because exercise produces a similar physiological response as physical stressors. When administered during consolidation, acute stress, both physical and psychological, consistently enhances episodic memory, particularly memory for emotional materials. Here we investigated whether a single bout of resistance exercise performed during consolidation can produce episodic memory benefits 48 h later. We used a one-leg knee extension/flexion task for the resistance exercise. To assess the physiological response to the exercise, we measured salivary alpha amylase (a biomarker of central norepinephrine), heart rate, and blood pressure. To test emotional episodic memory, we used a remember-know recognition memory paradigm with equal numbers of positive, negative, and neutral IAPS images as stimuli. The group that performed the exercise, the active group, had higher overall recognition accuracy than the group that did not exercise, the passive group. We found a robust effect of valence across groups, with better performance on emotional items as compared to neutral items and no difference between positive and negative items. This effect changed based on the physiological response to the exercise. Within the active group, participants with a high physiological response to the exercise were impaired for neutral items as compared to participants with a low physiological response to the exercise. Our results demonstrate that a single bout of resistance exercise performed during consolidation can enhance episodic memory and that the effect of valence on memory depends on the physiological response to the exercise.     

The genetic structure of Cloninger's seven-factor model of temperament and character in a Japanese sample

Theoretical assumptions regarding the genetic and environmental structure of personality proposed in Cloninger's seven-factor model of temperament and character were verified in a Japanese sample by using the twin method. The Temperament and Character Inventory (TCI) was administered to 296 twin pairs ranging in age from 14 to 28 years old. Among four temperament dimensions (novelty seeking [NS], harm avoidance [HA], reward dependence [RD], and persistence [PS]), HA and PS showed significant additive genetic contributions and no shared environmental effect, supporting the original theoretical assumption. NS and RD could be explained by either genetic or shared environmental factors with nonshared environment. All three character dimensions (cooperativeness [CO], self-directedness [SD], and self-transcendence [ST]) could be explained exclusively by additive contributions and no shared environmental effect. Multivariate genetic analysis indicated that there were no significant associations between NS, HA, and RD, as the theory predicts, and the genetic components of PS, SD, and CO were derived from those of the temperament dimensions. The fourth genetic component, which had a substantial load specifically on ST and overlapped with PS, was identified. Although most of the nonshared environmental effects were trait-specific, the phenotypic correlation between NS and HA could be explained by nonshared environmental overlap.     

How do Children Evaluate the Gossiper of Negative Gossip?

In this study, we investigated how children evaluate gossipers. There are two conflicting ways in which children evaluate the gossiper of negative gossip about another person. One is that they perceive the gossiper of negative gossip as bad because saying something negative about another person can be seen as indirect aggression. The other is that they perceive the gossiper of negative gossip as good because such gossip is beneficial to regulate their relationship with the gossip's target. To address the issue, we asked 7- and 8-year-olds to choose the gossiper of negative gossip or the gossiper of neutral gossip as a cooperative partner and to distribute resources between the gossipers. We found that the children often did not choose the gossiper of negative gossip as a partner and did not distribute many resources to her, indicating a perception of the negative gossiper as bad. This suggests that children's evaluation of a gossiper is influenced by the valence of gossip rather than the value of gossip.