Masahisa Kodama

Evaluation of sleep using ambulatory skin potential recording : Differences between morning and evening type

Abstract In order to validate the evaluation of sleep using cassette type ambulatory skin potential measurement system (C‐SPA), sleep duration variables extracted from 24 h recordings were compared between two groups (16 of the intermediate type and 16 of the evening type) with different sleep‐wake habits rated by Morningness and Eveningness Questionnaires (MEQ). Compared with the intermediate type, the evening type subjects go to bed and get up later, have difficulty in falling asleep and more frequently awaken during sleep. Thus, the sleep variables by C‐SPA provide valuable information about duration of sleep and differentiate the Sleep‐wake habits.

Continuous recordings of skin conductance change during sleep

Using a new compact and stable device, skin conductance change (SCC) was measured in five female undergraduates during sleep. The SCC trends and waveforms were almost identical to those of simultaneously recorded skin potential activity (SPA). A gradual increase in sympathetic sweating during sleep was also observed using SCC. However, the confounding effects of a burst of positive skin potential responses usually seen in SPA were absent using SCC.

Use of ambulatory skin conductance recording for monitoring psychophysiological arousal in the elderly staying in care facilities

Abstract To monitor the psychophysiological arousal level in the elderly, 24 h recordings of skin conductance change (SCC) were done during their stay in care facilities. The mean and maximum SCC levels in 17 awake elderly subjects were significantly lower than those of levels in 20 healthy, young control subjects (P < 0.05 and P < 0.001, respectively). The mean SCC levels during sleep did not differ between groups. The SCC trend graph reflected a degree of daily activity. The daytime SCC profile of elderly individuals who could walk independently was comparable to that of healthy young subjects. In contrast, the SCC profile of the bedridden elderly were generally flattened with poor SCC responses that were evoked only by nursing procedures.

Skin blood flow responses during sleep by laser Doppler flowmetry

Skin surface blood flow at the fingertips was measured in a 21‐year‐old woman during sleep using laser Doppler flowmetry. Skin blood flow responses (SBFR) are transient reductions in skin blood flow of about 25 s in duration. In our subject, SBFR showed a delay time of 8–9 s from the onset of skin potential responses (SPR) and appeared more consistently than SPR. The frequency of SBFR decreased during non‐rapid eye movement sleep, especially when the sleep stage became deep. These findings indicate the validity of SBFR as a discrete index of autonomic function during sleep.

Factor Structure in the Imagery of Fragrance: Study of Generational Differences

The psychological and physiological effects of fragrances on humans have been addressed in a number of studies [1–3]. However, there have been few reports about the evaluation of fragrance by imagery [1]. In this study, we examined generational differences in the evaluation of imagery for six fragrant oils: lemon, sandalwood, lavender, rose, peppermint, and eucalyptus.

Factor Structure in the Imagery of Fragrance: Study of Differences Between the Sexes

Fragrances influence humans both physiologically and psychologically, and they have also been used to reduce stress responses, as in aromatherapy. The physiological response to fragrance has been determined bioelectronically in many studies [1,2], but there have been few studies of the psychological evaluation of fragrance by imagery. Takeuchi et al. [3], in their study of imagery and fragrance, noted that five factors: freshness, nature, passion, activity, and femininity were associated with the images of 19 kinds of fragrances. They also found that the scores for each factor differed in the 19 kinds of fragrances tested and that there were sex differences in the factor scores.

Effects of Fragrances on Work Efficiency

Aromatherapy, which has been used for a long time, has shown that fragrances have not only psychological but also physiological influence in humans. The effects of fragrances on recovery from fatigue brought about by a mental workload have been reported [1–3]; however, to our knowledge, there are few studies of the effects of fragrances on psychological stress induced by monotonous work. We carried out this study to examine such effects.