The Effects of Relaxation and Postural Training on External Perception: Improvement of Visual Acuity, Visual Field, and Hearing Acuity

This study examined the effects of muscular relaxation and postural training on external perception using a visual acuity test, a visual field test, and a hearing acuity test. Eighteen undergraduate students were randomly assigned to experimental and control groups. The experimental group underwent muscular relaxation and postural training. Each subject in this group was administered the tests before and after the training. Each subject in the control group carried out the tests before and after participating in a 30-min conversation with the experimenter. On all three tests, the experimental group improved significantly more than the control group.     

On the perception of two successive sound bursts

Summary This paper is concerned with both time perception and the methodology of perceptual psychology. The perception of the pattern of two successive sound bursts was studied by two different methods, i.e., magnitude estimation and phenomenal report. The temporal interval between the bursts was varied from 38 ms to 3394 ms. First, the observer estimated the duration or speed of each pair by a number without modulus. The estimations could not be fitted by a single power function across the entire range of intervals. That is, the exponent changed discontinuously. Next, the observer categorized freely the impressions of all the pairs. The quality of the phenomenon changed at the point where the exponent changed. All the observers arrived at the same three categories expressing the phenomena of the pairs. The boundaries between them corresponded approximately to the intervals of 150 ms and 2000 ms. The pairs in the middle category were often associated with body movements. The other categories also are of a unique nature. Finally, the possibility and the usefulness of employing psychophysical methods and phenomenological methods together is discussed.We are grateful to Professor Y. Umeoka, University of Tokyo, for his constant advice     

The category of 1:1 ratio caused by assimilation of two neighboring empty time intervals

We investigated the perception of temporal patterns of two neighboring empty time intervals, t1 and t2, in this order. In a previous study, we reported that bilateral assimilation took place during t1 and t2, as well as unilateral assimilation. [Miyauchi, R. & Nakajima, Y. (2005). Bilateral assimilation of two neighboring empty time intervals. Music Perception, 22, 411-424]. The points of subjective equality (PSEs) of t1 and t2 approached each other. We speculated that these temporal patterns would yield nearly 1:1 ratios perceptually despite the change in the physical temporal ratio between t1 and t2. However, we were uncertain whether these temporal patterns were really perceived as having 1:1 ratios. In the present study, we conducted three experiments. In Experiment 1, we measured subjective similarities of two temporal patterns and analyzed the results by hierarchical cluster analysis and multidimensional scaling. The temporal patterns, where the physical ratio between t1 and t2 was varied systematically, were divided into three clusters, and one cluster consisted of the temporal patterns within a range of -80 ms 相似文献   

The nature of stress experienced by lesbians and gay men

This study examined both the meanings and sources/causes of stress from the perspectives of lesbians and gay men (n=30), using a series of focus groups. The findings suggest that stress is considered a part of life itself, and is perceived to contain both negative (e.g. detrimental effects on health and overall functioning, unfairness, out-of-control), and positive (e.g. a motivator, growth-facilitator) elements. The sources/causes of stress (i.e. stressors) identified include stress experienced from the "coming out" process, stress in family relations and intimate relationships, conflict over one's sexuality given society's homophobic and heterosexist attitudes toward lesbians and gay men, as well as stress from financial and work-related issues. More importantly, this study suggests that culture/ethnicity, gender, and aging, which are interconnected with one's sexual identity, play an important role in shaping the experiences of stress among lesbians and gay men.     

In situ measurement of GaN film photoluminescence under plasma etching

This work focuses on an improved method that enables us to measure in situ GaN film photoluminescence (PL) under Ar or N₂ plasma etching. Although the background signal is large and increases with bias voltage, the GaN PL can be obtained after subtraction of this background from the total luminescence. Moreover, after plasma etching, the intensities of the near-band-edge and the yellow luminescence decrease significantly. It is suggested that this behaviour is strongly related to the heavy plasma-induced damage, which includes non-radiative defects and deep-level defects, such as Ga vacancies and/or C impurities.     

Effects of temporal shapes of sound markers on the perception of interonset time intervals

This study investigated how the temporal characteristics, particularly durations, of sounds affect the perceived duration of very short interonset time intervals (120-360?ms), which is important for rhythm perception in speech and music. In four experiments, the subjective duration of single time intervals marked by two sounds was measured utilizing the method of adjustment, while the markers' durations, amplitude difference (which accompanied the duration change), and sound energy distribution in time were varied. Lengthening the duration of the second marker in the range of 20-100?ms increased the subjective duration of the time interval in a stable manner. Lengthening the first marker tended to increase the subjective duration, but unstably; an opposite effect sometimes appeared for the shortest time interval of 120?ms. The effects of varying the amplitude and the sound energy distribution in time of either marker were very small in the present experimental conditions, thus proving the effects of marker durations per se.     

Perceptual completion of a sound with a short silent gap

Listeners reported the perceptual completion of a sound in stimuli consisting of two crossing frequency glides of unequal duration that shared a short silent gap (40 ms or less) at their crossing point. Even though both glides shared the gap, it was consistently perceived only in the shorter glide, whereas the longer glide could be perceptually completed. Studies on perceptual completion in the auditory domain reported so far have shown that completion of a sound with a gap occurs only if the gap is filled with energy from another sound. In the stimuli used here, however, no such substitute energy was present in the gap, showing evidence for perceptual completion of a sound without local stimulation ('modal' completion). Perceptual completion of the long glide occurred under both monaural and dichotic presentation of the gap-sharing glides; it therefore involves central stages of auditory processing. The inclusion of the gap in the short glide, rather than in both the long and the short glide, is explained in terms of auditory event and stream formation.     

Time-shrinking: the process of unilateral temporal assimilation

Our previous research on auditory time perception showed that the duration of empty time intervals shorter than about 250 ms can be underestimated hugely if they are immediately preceded by shorter time intervals. We named this illusion 'time-shrinking' (TS). This study comprises four experiments in which the preceding interval, t1, was followed by a standard interval, t2. When t1 < or = 200 ms, and t1 < or = t2, the underestimation of t2 came into view clearly. The absolute difference between t2 and t1 was the crucial factor for the illusion to appear. The underestimation increased when t2 increased from t1 to t1 + 65 ms, stayed at about 45 ms when t2 was between t1 + 65 ms and t1 + 95 ms, and disappeared suddenly when t2 exceeded t1 + 95 ms. This pattern of results was observed across all values of t1 < or = 200 ms. A model was fit to the data to elucidate the underlying process of the illusion. The model states that the perceived duration difference between t1 and t2 is reduced by cutting mental processing time for t2; in other words, that t2 assimilates to t1.     

Acute restraint stress enhances calcium mobilization and proliferative response in splenic lymphocytes from mice

Calcium (Ca2+ ) plays an essential role in lymphocyte activation and maturation. Acute and chronic stress has been shown to modulate the lymphocyte immune response; but the relationship between cytosolic free Ca2+ concentration ([Ca2+ ]i) and the immune response in lymphocytes following exposure to stress has not been examined. In the present study, we investigated the effects of acute restraint stress on [Ca2+ ]i and the proliferation of splenic lymphocytes from mice. We observed that 2 h of restraint significantly increased plasma corticosterone levels in mice. On examining [Ca2+ ]i and the proliferation ex vivo of splenic lymphocytes isolated from restraint-stressed mice using fura-2 and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, respectively, we found that acute restraint stress caused a significant increase in resting [Ca2+ ]i and significantly enhanced the ability of concanavalin A (Con A; a T-cell-selective mitogen) to increase [Ca2+ ]i but not that of lipopolysaccharide (LPS; a B-cell-selective mitogen). In addition, acute restraint stress significantly enhanced Con A-stimulated but not LPS-stimulated lymphocyte proliferation. Overall, there was a positive correlation between [Ca2+ ]i and T-cell proliferation following acute restraint stress. The enhancements of [Ca2+ ]i and T-cell proliferation were completely suppressed by verapamil (a Ca2+ channel blocker). These results suggest that acute restraint stress enhances Con A-stimulated T-cell proliferation by increasing [Ca2+ ]i via stimulation of Ca2+ entry.