A reversed Ebbinghaus–Titchener illusion in bantams (Gallus gallus domesticus)

A disk surrounded by smaller disks looks larger, and one surrounded by larger disks looks smaller than reality. This visual illusion, called the Ebbinghaus–Titchener illusion, remains one of the strongest and most robust illusions induced by contrast with the surrounding stimuli in humans. In the present study, we asked whether bantams would perceive this illusion. We trained three bantams to classify six diameters of target disks surrounded by inducer disks of a constant diameter into “small” or “large”. In the test that followed, the diameters of the inducer disks were systematically changed. The results showed that the Ebbinghaus–Titchener figures also induce a strong illusion in bantams, but in the other direction, that is, bantams perceive a target disk surrounded by smaller disks to be smaller than it really is and vice versa. Possible confounding factors, such as the gap between target disk and inducer disks and the weighted sum of surface of these figural elements, could not account for the subjects’ biased responses. Taken together with the pigeon study by Nakamura et al. (J Exp Psychol Anim Behav Process 34:375–387 2008), these results show that bantams as well as pigeons perceive an illusion induced by assimilation effects, not by contrast ones, for the Ebbinghaus–Titchener types of illusory figures. Perhaps perceptual processes underlying such illusory perception (i.e., lack of contrast effects) shown in bantams and pigeons may be partly shared among other avian species.     

Parenting Self-Efficacy and Parental Involvement: Mediators or Moderators Between Socioeconomic Status and Children’s Academic Competence in Japan and Korea?

We examined the causes of a growing achievement gap associated with socioeconomic status (SES) in Korea and Japan, testing whether parenting self-efficacy (PSE) and parental involvement (PI) mediated or moderated the association of SES to children’s school-related competence (SRC). Three hundred and seventy-two Korean and 309 Japanese mothers of first- and second-grade children completed a parenting survey. Japanese mothers’ education and PSE were directly associated with SRC. PSE moderated the association of education to SRC, with higher PSE of college-educated mothers positively associated with SRC. In the Korean sample, household income was associated with SRC directly as well as indirectly through PSE.     

Production of regular rhythm induced by external stimuli in rats

Animal Cognition - Rhythmic ability is important for locomotion, communication, and coordination between group members during the daily life of animals. We aimed to examine the rhythm perception...     

Does Mealtime Communication Improve Happiness? Considering the Trait of Shyness1

Shared mealtimes have been found to be important daily rituals with positive effects on behavior and mental health, such as increasing subjective well-being. However, most previous studies have not considered possible barriers to these positive effects, specifically shyness. We investigated the relationships among shared mealtime quality, shyness, and subjective well-being, and the moderating role of shyness in the relationship between the other two variables by surveying a sample of college students (n = 305). Correlational analyses revealed that shared mealtime quality was negatively associated with shyness and positively associated with subjective well-being. Hierarchical regression analyses revealed that shared mealtime quality was significantly associated with subjective well-being, as was the interaction between the friend factor of shared mealtime quality and shyness. Therefore, shared mealtime quality might help improve happiness, but shyness should be considered a possible barrier to this beneficial effect when meals are shared with friends.     

Sensory Processing Sensitivity Moderates the Relationships Between Life Skills and Depressive Tendencies in University Students1

University students often experience depressive symptoms, and strengthening of life skills may be beneficial for improving their mental health. Several studies have suggested that life skills effective in reducing depressive tendencies vary by individuals depending on differences in sensory processing sensitivity (SPS). SPS is a genetically determined trait characterized by sensitivity and reactivity to environmental stimuli. This study investigated the relationship between life skills and depressive tendencies based on individual differences in SPS. A total of 868 Japanese university students (mean age = 19.8 years, SD = 1.3 years) completed a questionnaire measuring levels of SPS—decision-making, interpersonal relationships, effective communication, and emotional coping skills—and depressive tendencies. Hierarchical multiple regression and simple slopes analyses indicated that interpersonal relationship skills were negatively correlated with depression regardless of SPS levels. Furthermore, decision-making skills were negatively correlated with depressive tendencies only in low-SPS students. Emotional coping skills were negatively correlated with depressive tendencies in high-SPS students. These results may help universities incorporate SPS levels when creating life-skills-based interventions for students.     

Cultural differences in the development of cognitive shifting: East-West comparison

Prior research has documented that Japanese children's performance on the Dimensional Change Card Sorting (DCCS) task can be influenced by their observation of another person completing the task, which is referred to as social transmission of disinhibition. The current study explored whether Canadian children would also show a social transmission of disinhibition and whether their performance would be comparable to that of Japanese children. In this study, 3- and 4-year-olds in Canada and Japan were given both the standard version and social version of the DCCS. Results indicated that Canadian children displayed the social transmission of disinhibition, but their effects were significantly weaker than those with Japanese children. On the other hand, performance on the standard DCCS was comparable between children in the two countries. We discuss the results in terms of cultural differences in the relationship between self and other.     

Asymmetrical neural adaptation in lower leg muscles as a consequence of stereotypical motor training

Despite well-authorized facts regarding asymmetrical architectural changes between different limbs after persistent participation in particular motor training, no studies have addressed the neural aspects to the present. The authors undertook the study to elucidate the possibility of neural adaptation on a limb-by-limb basis after repetitive engagement in a particular motor training routine. We investigated lower leg muscles in endurance-trained track runners who have been trained by routinely running on a track in counterclockwise direction on curved paths. Stretch reflex responses in the plantarflexor muscles (soleus [SOL], medial [MG], and lateral head of the gastrocnemius muscle) were evaluated bilaterally with participants sitting at rest. Comparisons were made between homonymous muscles of the right (corresponding to outside leg for track running) and left leg (inside leg, likewise) and with a group of nontrained controls. The result clearly demonstrated that the responses were prominently different between the legs (thus, asymmetrical) in the MG muscles and partially in the SOL muscles in the trained group. In contrast, no such differences were obtained in the nontrained control group. The result demonstrated that neural adaptation took place asymmetrically and that could be attributable to their repetitive engagement in the stereotypical motor task.     

Asymmetrical drawing patterns on the temples by left-handers

Twenty-three Japanese genuine left-handers were selected by a Laterality Quotient scale and asked to draw the letter S on their own temples and foreheads. The way they drew on the temples showed an asymmetry that was the mirror reversal of that of right-handers, as found in a previous study. Left-handers drew a reversed letter S on their right temple much more often than on the left temple, whereas right-handers drew them in reverse more often on the left temple. They also drew it in reverse on the forehead irrespective of their handedness.     

Capuchin monkeys (<Emphasis Type="Italic">Cebus apella</Emphasis>) use conspecifics’ emotional expressions to evaluate emotional valence of objects

Emotional expressions provide important clues to other individuals’ emotional states, as well as the environmental situations leading to such states. Although monkeys often modify their behavior in response to others’ expressions, it is unclear whether this reflects understanding of emotional meanings of expressions, or simpler, non-cognitive processes. The present study investigated whether a New World monkey species, tufted capuchin monkeys, recognize objects as elicitors of others’ expressions. Observer monkeys witnessed another individual (demonstrator) reacting either positively or negatively to the contents of one of two containers and were then allowed to choose one of the containers. The observer preferred the container that evoked positive expressions in the demonstrator and avoided the container that evoked negative expressions. Thus, the monkeys appropriately associated the emotional valence of others’ expressions with the container. This finding supports the view that the ability to represent others’ emotions is not limited to humans and apes.