The functional role of central and peripheral vision in the control of posture

Three experiments were conducted to investigate the role of central and peripheral vision (CV and PV) in postural control. In Experiment 1, either the central or peripheral visual field were selectively stimulated using a circular random dot pattern that was either static or alternated at 5 Hz. Center of foot pressure (CoP) was used to examine postural sway during quiet standing under both CV and PV conditions. The results showed that, when the visual stimulus was presented in the periphery, the CoP area decreased and more so in the anterior-posterior (AP) than in the medio-lateral (ML) direction, indicating a characteristic directional specificity. There was no significant difference between the static and dynamic (alternating) conditions. Experiment 2 investigated the directional specificity of body sway found in Experiment 1 by having the trunk either be faced toward the stimulus display or perpendicularly to it, with the head always facing the display. The results showed that the stabilizing effect of peripheral vision was present in the direction of stimulus observation (i.e., the head/gaze direction), irrespective of trunk orientation. This suggested that head/gaze direction toward the stimulus presentation, rather than a biomechanical factor like greater mobility of the ankle joint in AP direction than in ML direction, was essential to postural stability. Experiment 3 further examined whether the stabilizing effect of peripheral vision found in Experiments 1 and 2 was caused because more dots (500) were presented as visual cues to the peripheral visual field than to the central visual field (20 dots) by presenting the same number of dots (20) in both conditions. It was found that, in spite of the equal number of dots, the postural sway amplitudes were larger for the central vision conditions than for the peripheral vision conditions. In conclusion, the present study showed that peripheral rather than central vision contributes to maintaining a stable standing posture, with postural sway being influenced more in the direction of stimulus observation, or head/gaze direction, than in the direction of trunk orientation, which suggests that peripheral vision operates primarily in a viewer-centered frame of reference characterized by the head/gaze direction rather than in a body-centered frame of reference characterized by the anatomical planes of the body.     

Association of maternal smoking during pregnancy and infant neurobehavioral status

The association of maternal smoking during pregnancy with neurobehavioral status was examined in 344 Japanese infants. Based on a questionnaire, their mothers were classified into three groups, Nonsmokers, Exsmokers, and Smokers. The Neonatal Behavioral Assessment Scale was administered three days after birth. Among the three groups, on the seven clusters and their 28 behavioral subscales there were no significant differences. The infants of Smokers had lower scores than those of Exsmokers and Nonsmokers on two behavioral items, general tone and peak of excitement. General tone remained significant after adjustment for covariates.     

Effect of luminance contrast on the motion aftereffect

The effects of luminance contrast and spatial frequency on the motion aftereffect were investigated. The point of subjective equality for velocity was measured as an index of the motion aftereffect. The largest effect was observed when a low contrast grating (5%) was presented as a test stimulus after adaptation to a high contrast grating (100%) in the low spatial frequency condition (0.8 cycle deg.-1). On the whole, the effect increased with increasing adapting contrast and with decreasing test contrast or spatial frequency. Small effects were observed at high test contrasts. These results were inconsistent with those of Keck, Palella, and Pantle in 1976. Analysis showed that there was no saturation on velocity of the motion aftereffect above 5% of the contrast although Keck, et al. (1976) found that the incremental increases of the effect above 3% adapting contrast were small.     

A cognitively-gated place? The role of need for closure in a biased perception of the place’s past

Biased memory of the past is often a starting point for intergroup conflicts. In three correlational studies, we examined the relationship between need for closure (NFC) and historical ethnocentric bias, a tendency to overestimate the role of one’s ethnic group in the multicultural history of the city of residence. In addition, we checked whether this relationship would be mediated by an individual preference for essentialist places. We found that higher NFC was related to increased historical ethnocentric bias. Moreover, this relation was mediated by preference for an essentialist type of a place. Our results may contribute to understanding the role of individual differences and preferred type of place in shaping a biased representation of the past. Furthermore, our research findings point to the importance of raising awareness of the multicultural past among high NFC individuals.

     

Writing errors and anosognosia in amyotrophic lateral sclerosis with dementia

Amyotrophic lateral sclerosis (ALS) with dementia (ALS-D) is known to exhibit characteristics of frontotemporal dementia. However, in clinical situations, it is often difficult to evaluate their cognitive functions because of impaired voluntary speech and physical disabilities. In order to identify characteristic and diagnostic cognitive symptoms of relatively advanced ALS-D patients, we retrospectively reviewed the clinical features of seven cases of clinically definitive ALS who had dementia, impaired voluntary speech, and physical disability. Their medical records showed that six out of seven patients made writing errors, and all of the patients demonstrated anosognosia. The writing errors consisted of paragraphia such as substitution, omission, or syntactic errors with individual differences in error types. Dissociation between kana and kanji were also observed. Anosognosia was evaluated by a self-rating scale with which the patients and the medical staff evaluated the patient's physical ability; the results indicated a large discrepancy between the evaluation by the patients and the medical staff. We emphasize that aphasic writing errors have been underestimated, particularly in ALS-D patients with impaired voluntary speech. We also reported that anosognosia was the most important and quantifiable symptom in ALS-D. The relationship between writing errors and anosognosia should be investigated further.     

The ego, the Other and the primal fact

Japan has absorbed many western ideas since the late nineteenth century, but Japanese philosophers have often been reluctant to accept the western idea of the “I” in its entirety. The I transgresses to the Other more easily than western philosophies think and imports what belongs to the Other as his own. How is this possible? Husserl attempted to explain the constitution of the Other by the intentionality that goes from the I to the Other, mediated by the body. However, Husserl later discovered that the constitution of both the I and the Other is more of a two-way movement. This double-movement is essential for all constitutions and departs from a deep (primal) dimension that is not yet egological. Even in the self-reflection of the I, a similar double-movement between the primal and egological dimensions can be seen. The I is supported, but at the same time threatened, by this movement.     

Vulnerability factors in depression: The facets of sociotropy and autonomy

Sociotropy-autonomy (Beck, 1983) describes a set of personality dimensions that relate to an individual's vulnerability to depression. Two recently developed scales, the Sociotropy-Autonomy Scale (Clark & Beck, 1991) and the Personal Style Inventory (Robinset al., 1994), have been developed in order to assess these personality dimensions. Typically, these measures are used in isolation and little published information is available concerning their interrelationship. The present study examined the relationship between the two scales and specified the various factors that emerge when the items of the two scales are integrated. Six hundred fifty-two participants responded to the Personal Style Inventory (Robinset al, 1994) and the Sociotropy-Autonomy Scale (Clark & Beck, 1991). A factor analysis on all of the items of the two scales revealed a five-factor structure (two sociotropy, two autonomy, and one achievement factor). The relationships among depression, the five derived factors, and the original scales developed by Clark and Beck (1991) and Robinset al. (1994) were critically examined. The results are discussed in the context of vulnerability to depression.     

Three elemental illusions determine theZöllner illusion

We have discovered an apparent contraction illusion of acute angles in a special form of the Zöllner figure at the intersecting angles between 36° and 83° (i.e., a reversal of the Zöllner illusion). The necessary condition for this illusion is that inducing lines are long enough and the induced Une (test line) is single. When an illusory line is usedas the induced line, the magnitude of contraction increases. Short inducing lines give no illusion or a slight expansion of acute angles at the intersecting angle of 45°. We have ascertained that the source of this expansion is the narrow region in the vicinity of the induced line, whereas the source of the contraction is much broader regions. Furthermore, we have discovered another expansion mechanism, which is generated by the symmetrical configuration of the standard Zöllner figure.