Shaping of scientific psychology in Japan

Japanese scientific psychology began with Y. Motora's lecture on pyschophysics at the University of Tokyo in 1888. He had just received his PhD under G.S. Hall at Johns Hopkins University, in the USA. He became the first professor of psychology in 1890 and founded the first psychological laboratory at the University of Tokyo in 1903. He studied many psychological problems, including attention, experimentally and theoretically. One of his first students, Matataro Matsumoto, founded the second psychological laboratory at Kyoto University and then succeeded to Motora's position in Tokyo. Matsumoto was interested in experimental studies of human performance and their applications. He trained many able psychologists and organized the Japanese Psychological Association in 1927. Some of his students founded more psychological laboratories in major universities of Japan. They introduced psychological tests, Gestalt psychology, and behaviourism in the 1920s and 1930s. Psychoanalysis was introduced through mainly nonacademic roots and became familiar to Japanese psychologists in the 1930s. After World War II, a strong influence of American psychology came to Japanese psychologists who had already trained in scientific methodology. The areas of research and applications have been greatly widened and the number of psychologists has increased rapidly up to the present day. Promotion of international interactions and indigenous traditions are both expected.     

Minimum Muscle-Tension Change Trajectories Predicted by Using a 17-Muscle Model of the Monkey's Arm

Four computational problems to be solved for visually guided reaching movements, hand path, and trajectory formations, coordinate transformation, and calculations of muscle tensions are ill-posed in redundant biological control systems. These problems are ill-posed in the sense that there exist an infinite number of possible solutions. In this article, it is shown that the nervous system can solve those problems simultaneously by imposing a single global constraint: finding the smoothest muscle- tension trajectory that satisfies the desired final hand position, velocity, and acceleration. Horizontal trajectories were simulated by using a l7-muscle model of the monkey's arm as the controlled object. The simulations predicted gently curved hand paths for lateral hand movements and for movements from the side of the body to the front, and a roughly straight hand path for anterioposterior movements. The tangential hand velocities were roughly bell shaped. The simulated results were in agreement with the actual biological movements.     

Constructing a continuum of predicate extensions of each intermediate propositional logic

Wajsberg and Jankov provided us with methods of constructing a continuum of logics. However, their methods are not suitable for super-intuitionistic and modal predicate logics. The aim of this paper is to present simple ways of modification of their methods appropriate for such logics. We give some concrete applications as generic examples. Among others, we show that there is a continuum of logics (1) between the intuitionistic predicate logic and the logic of constant domains, (2) between a predicate extension ofS4 andS4 with the Barcan formula. Furthermore, we prove that (3) there is a continuum of predicate logics with equality whose equality-free fragment is just the intuitionistic predicate logic.Dedicated to the memory of the late Professor S. MaeharaThis research was supported in part by Grant-in Aid for Encouragement of Young Scientists No. 06740140, Ministry of Education, Science and Culture, Japan.Presented byHiroakira Ono     

Effectiveness of color in picture recognition memory

Investigations were conducted into the effectiveness of color in picture recognition memory. In the study phase, half of the pictures were presented in color and the other half in black and white. In the test phase, half were presented in the same color mode as the study pictures and the other half in the other mode. In immediate and 1-week-delayed tests, the recognition performance was highest when color pictures were used in both the study and test phases. The recall for the color mode of the study pictures, however, was not as good, even with the color pictures. This suggests that the effectiveness of color in picture recognition is not necessarily due to the memory for colors in the pictures themselves, but is probably due to the distinctiveness of features highlighted by the colors. We also found that in the recall performance for the color mode it was more difficult to detect the deletion of colors than to detect their addition.     

Visual evoked potentials to the geometric forms in the randomized presentation

Two outlined geometric figures, an equilateral triangle and a circle, of equal contour length, were randomly presented at a fixed position in the lower or upper part of the visual field (LVF and UVF). Transient visual evoked potentials (VEPs) were recorded monopolarly from the inion (I), 5, 10, 15 cm above it (I5, I10, I15) and Fz, for 12 subjects. Grand-averaged VEPs were computed. A negative (N) wave (averaged peak latency 155 ms) was identified in the LVF and a positive (P) wave (130 ms) in the UVF. In the LVF, the N amplitude of the triangle was significantly larger than that of the circle at I5 and I. Regarding the P wave in the UVF, the triangle was of a significantly longer latency than the circle at I15, I10 and I5. The enhancement of the N amplitude for the triangle in the LVF is not attributable to the arousal caused by the preparatory state for the figure, since the subject could not predict the figure to be presented next or its position.     

Genetic and Environmental Influences on Personal and Rhythmic‐Motor‐Activity Tempo in Children: A Twin Study

In this study, we investigated the degree to which genetics and environmental factors influence the tempo and tempo stability of rhythmic motor activity in young children, using a twin study design. A total of 116 twin children, aged 4 years, were asked to strike two small clash cymbals together in a cyclical manner, in three phases. In the first phase, children were asked to maintain a comfortable personal tempo of rhythmic motor activity (spontaneous motor phase). In contrast, in the other phases, children were required to synchronize rhythmic motor activity in response to the timing of a stimulus tone, or a memorized tempo. Large additive genetic, although negligible shared environmental influences, were observed in the spontaneous motor phase. However, environmental factors were estimated in the other two phases, while the additive genetic factor was nearly zero. These results indicate that the extent of genetic and environmental influences on individual differences in rhythmic motor activity can be modulated under different situations.     

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.     

Relationship between implicit false belief understanding and role play: Longitudinal study

Pretend play is one of the earliest forms of children’s imagination. While social pretend play (role play) may facilitate the development of theory of mind – including false belief understanding – theoretically, the reverse may be true; theory of mind may facilitate the development of role play. To clarify this relationship, the present longitudinal study examined whether toddler’s implicit understanding of false beliefs predicted their role play during preschool years. We examined 18-month-old toddlers’ looking time in an implicit false-belief task (Time 1). When the children were 4/5 years old (Time 2), children’s parents answered a questionnaire on their child’s engagement in role play, such as playing with an imaginary companion and impersonating an imagined character. Toddlers’ looking time in the false-belief task at Time 1 predicted impersonation scores at Time 2. The results suggest that early theory of mind skills can facilitate children’s role play.     

Effects of contingencies of self‐worth and sensitivity to indebtedness on optimistic bias in seeking help for depression

The occurrence of the optimistic bias in seeking help for depressive symptoms has been attributed to the threat‐to‐self and equity theories. The current study tested the hierarchical relationships between contingencies of self‐worth (CSW), self‐esteem (SE), sensitivity to indebtedness (SI), and optimistic bias in seeking formal/informal help for depression. An online questionnaire survey was conducted with Japanese university students (n = 1000). Results from structural equation modeling analysis revealed the mediating effect of CSW on SE and optimistic bias. SI was positively related to optimistic bias in symptom recognition and informal help‐seeking. The results suggest that both CSW and SI are responsible for the occurrence of optimistic bias in seeking help for depression. Cognitive patterns in recognizing personal and others' depressive symptoms and needs for seeking help were discussed.