Compensatory coordination of release parameters in a throwing task

The consistency and coordination of release parameters in ball-throwing movements were investigated. The authors used a newly developed index of coordination for release parameters (ICRP) that quantifies the degree of improvement of performance consistency caused by compensatory relationships among parameters (i.e., not caused by consistency of parameters). Eight participants practiced for 150 trials, with the nondominant hand, a ball-throwing task aimed at a stationary target. The magnitude of the ball-release velocity vector, among release parameters, as well as the performance was found to become consistent with practice. The ICRP score suggested that the release parameters were complementarily coordinated with one another, and that the coordination improved with practice. Those results indicate that compensatory relationships among varying release parameters contribute to reducing the variability of performance in a ball-throwing task whose goal is accuracy.     

The relation between preparatory stance and trunk rotation movements

The influence of preparatory stance on rotation movement reaction time of the trunk by bending of the knee and hip joint(s) was examined in 12 subjects. Four preparatory stances were examined: straight knee and hip extension (STAND), slight flexion of knee joints and hip joint (LIGHT), deep flexion (DEEP), and free initial position, i.e. that felt to be the most comfortable and effective (FREE). There was no significant influence of the preparatory stance on hip latency, but there were significant differences between the preparatory stances on response time (RT) and movement time (MT). Furthermore, using a quadratic curve fitting technique, knee joint angles of 24.8 degrees and a hip joint angle of 23.3 degrees were shown to be the optimum flexion angles in the preparatory stance for the initiation of quick trunk rotation movements. It is proposed that mechanical factors have considerably more effects on trunk rotation movements than does the nervous system.     

The illness concept in adolescent psychiatry

This paper introduces some important views on the clinical entities of the adolescent psychiatry in Japan. Shimizu shows the transitional region between neurosis, schizophrenia and normal. Murakami's new classification tells the relationship among the psychiatric disorders, especially about the borderline disorder. Hatotani's scheme deals with the atypical psychoses very well. According to the idea of Griesinger's "Einheitspsychose" arranges my symptomatic picture several ambiguous symptoms of the adolescent psychiatric disorders. In this picture we can understand the meaning of the borderline disorder. At last I give the catastrophic model of psychiatric disorders.     

Emergence of symmetry in a visual conditional discrimination by chimpanzees (Pan troglodytes)

In Exp. 1, three young chimpanzees were trained to match red to a cross and green to a circle in an arbitrary matching-to-sample task. After acquisition of this task, they were tested for the emergence of associative symmetry of these conditional relations using the trials on which shapes were presented as samples and colors as comparisons. One of the three chimpanzees showed statistically significant accuracy on these test trials. This successful subject served in Exp. 2, in which an auditory-visual stimulus appeared contingent upon red and a cross while another auditory-visual stimulus was contingent upon green and a circle. This subject showed higher accuracies in symmetry tests than in Exp. 1, which suggested the facilitative effects of these events common to sample and correct comparison on the development of symmetry. In Exp. 3, subsequent tests in which only these stimuli were presented as samples indicated that these stimuli might have become the members of equivalence classes.     

Orientation dependence of spatial memory acquired from auditory experience

The present study investigated whether memory for a room-sized spatial layout learned through auditory localization of sounds exhibits orientation dependence similar to that observed for spatial memory acquired from stationary viewing of the environment. Participants learned spatial layouts by viewing objects or localizing sounds and then performed judgments of relative direction among remembered locations. The results showed that direction judgments following auditory learning were performed most accurately at a particular orientation in the same way as were those following visual learning, indicating that auditorily encoded spatial memory is orientation dependent. In combination with previous findings that spatial memories derived from haptic and proprioceptive experiences are also orientation dependent, the present finding suggests that orientation dependence is a general functional property of human spatial memory independent of learning modality.     

Computer‐based teaching of Kanji construction and writing in a student with developmental disabilities

Students with developmental disabilities often have difficulty with writing skills such as tracing, copying, and dictation writing. A student with writing difficulties participated in the present study, which used computer‐based teaching applied in the home. We examined whether a student could copy Japanese Kanji characters after training with a constructed response matching‐to‐sample (CRMTS) procedure. The procedure was designed to teach identity Kanji construction. The results showed that the student not only acquired the constructed responses through this procedure but also to spelling generalized to copy trained and untrained Kanji characters. The results are discussed in terms of the effect of the CRMTS procedure on the acquisition and transfer of writing characters and the applicability of computer‐based home teaching. Copyright © 2008 John Wiley & Sons, Ltd.     

Infant responses to maternal still-face at 4 and 9 months

This study investigated developmental changes in infant responses to maternal still-face (SF) situations. Infants (21 males and 25 females) of Japanese mothers were observed in a face-to-face SF paradigm, comprising four phases (normal/SF/normal/SF), at two infant ages (4 and 9 months). The infants' facial expression, gaze direction, and vocalization were coded in both SF and normal interaction conditions. The results indicated that infants at both ages showed a decrease in displaying positive facial expression and gazing at their mothers during SF conditions. The 4-month-old displayed emotional expression and directed their gaze toward their mothers more frequently than the 9-month-old. However, the 9-month-old vocalized more often in SF situations, attempting to elicit responses from their mothers. The "carry-over" effect was observed only in 9-month-old. The results were discussed in the context of developmental changes in infants' social skills to cope with an emotionally stressful situation.     

Computer‐based teaching of word construction and reading in two students with developmental disabilities

Students with developmental disabilities often have difficulty in learning the systematic relations between syllables (auditory stimuli) and characters (visual stimuli) required for reading. Two students with developmental disabilities participated in the present study which used computer‐based teaching applied in the home. We examined whether the students could read individual Japanese Hiragana characters after training with a constructional MTS procedure with differential outcome (DO) that was designed to teach word‐construction for pictured sample stimuli. The DO procedure provided the differential stimulus (in this case spoken syllables) after response selection. The results showed that the students not only acquired appropriate word‐construction responses through this task, they also learned to read Hiragana characters without direct training of this skill. The results are discussed in terms of the effect of the constructional MTS procedure with DO on the acquisition and transfer of reading characters and the applicability of computer‐based home teaching. Copyright © 2007 John Wiley & Sons, Ltd.     

Testing assumptions of deliberate practice theory relevance, effort, and inherent enjoyment of practice with a novel task: study II

This study examined three assumptions of the theory of deliberate practice: that deliberate practice is perceived as relevant for improving performance and that it requires effort, but that it is not perceived as being inherently enjoyable. Of particular interest was how these perceptions change as practice difficulty changes. 30 college undergraduates practiced two different maze memorization and replication tasks and rated the practice relevance for improving performance on the task, the practice effort, and the inherent enjoyment of practice. The findings for each of the assumptions were consistent with those suggested by the theory and also showed that these perceptions are subject to the current performance on an activity and the difficulty of the practice.