Eyeblinking during autokinetic movement observed by a subject living in the up-down inverted visual world

Eyeblinking during autokinetic movement observed by one subject living in the up-down inverted visual world, was investigated. The subject wore frame-spectacles (without prisms) for the first two days and then wore up-down inverting spectacles (with prisms) for the next four days, followed by the resumption of the former frame-spectacles for one day. Eyeblinks during autokinetic movement were measured by using vertical EOG. Analysis showed (1) the occurrence of eyeblinking during autokinetic movement was not influenced by living in the up-down inverted visual world; (2) the frequency of eyeblinking during autokinetic movement significantly decreased with successive days of observation.     

Effects of up-down visual inversion on motor skills

The movement of a hand or fingers and locomotion of the body by a subject wearing prisms which inverted his visual world were investigated. A subject wore frame-spectacles (without prisms) for the first two days and then wore up-down inverting spectacles (with prisms) for the next four days, followed by wearing the former frame-spectacles again for one day. Measurements were made of skill on star-drawing, pegboard tests, and on zigzag-walking and walking up and down stairs. There were no differences on the five measures during acquisition for the four tasks, which suggests smooth progress of prism-adaptation by this man.     

Effects of living in the up-down inverted visual world on apparent movement

The purpose of this study was to examine whether a change of perceptual framework may affect the occurrence of apparent movement. Apparent movement was observed by one subject living over four days in the prismatically inverted visual world, because this situation was considered as the operation in which the subject was forced to change the perceptual framework to adapt himself to the novel environment. Apparent movement with two points was measured in vertical and horizontal configurations before wearing and after removing the prism as well as while wearing it. Analysis showed significant effects of prism-wearing on the occurrence of apparent movement in both vertical and horizontal configurations. Although further elaboration is required, an hypothesis was suggested from the viewpoint of the loss of visual position constancy.     

Effect of reaction time condition on EMG activities of the biceps brachii muscle in elbow flexion and forearm supination

Under simple- and choice-RT conditions, the biceps brachii muscle was examined in 8 healthy male subjects to determine how the temporal and spatial characteristics of elbow flexion and forearm supination differed at the initial phase of EMG activity and whether preparation or the presence of response uncertainty influenced the EMG outputs of the two movements. In the simple-RT condition, RT of supination was significantly faster than that of flexion but EMG activity of supination was less than that of flexion. In contrast, in the choice-RT condition, RT of flexion was significantly faster than that of supination but EMG activity of flexion was significantly reduced compared to supination. These findings indicate that advanced preparation or motor set facilitates the differentiation of RTs and EMG activities of the response movements and that response uncertainty causes a significant change in the temporal and spatial specificity of both elbow flexion and forearm supination.     

Contemporary theories of group psychotherapy: a systems approach to the group-as-a-whole.

The author discusses how subgroups represent the basic focus of the systems-centered group therapist. Particular attention is given to boundary issues and to how therapy takes place by facilitating the process of discriminating, communicating, and integrating perception of differences in the apparently similar and similarities in the seemingly different. Communication occurs at the boundaries between systems at all levels of the hierarchy: the group, the subgroup, and its members. Clinical vignettes are provided to illustrate important process issues, such as work with difficult patients, levels of intervention, and group resistance and defense.     

Postural requirements and progression velocity in young walkers

This article describes developmental changes in gait velocity and relates these changes to gait parameters that index postural stability (step width and lateral acceleration) and two components of velocity (cadence and step length). Five children were observed longitudinally over a 2-year period after onset of independent walking. Their range of speed increased threefold in the first 6 months of independent walking and then remained constant. In contrast, step width decreased approximately twofold. Whereas in adults, cadence and step length contribute approximately equally to speed, when infants first begin to walk independently, increase in velocity is due mostly to increased step length. After 5 months of independent walking, the pattern reverses, and increase in velocity is due primarily to increased cadence. The pattern remains constant over the next 18 months. From a developmental point of view, the data lead us to interpret early walking (the first 5 months) as a process of integration of postural constraints into the dynamic necessities of gait movement. A second phase, beginning after 4 to 5 months of independent walking, is considered to be a tuning phase characterized by a more precise adjustment of the gait parameters.