Takeshi Morikawa

Emotional, restorative and vitalizing effects of forest and urban environments at four sites in Japan.

The present study investigated the well-being effects of short-term forest walking and viewing (“forest bathing”). The hypothesis in our study was that both environment (forest vs. urban) and activity (walking and viewing) would influence psychological outcomes. An additional aim was to enhance basic research using several psychological methods. We conducted the experiments using 45 respondents in four areas of Japan from August to September, 2011. The hypothesis in our study was supported, because significant interaction terms between the environment and activity were confirmed regarding the Profile of Mood States (POMS) indexes, Restorative Outcome Scale (ROS) and Subjective Vitality Scale (SVS). No statistical differences between the two experimental groups in any of the ten scales were found before the experiment. However, feelings of vigor and positive effects, as well as feelings of subjective recovery and vitality were stronger in the forest environment than in the urban environment.

Time-series variations of blood pressure due to contact with wood

It is known that contact with wood produces a gentle feeling, so wood has been used for floors and furniture, such as tables and chairs, that we touch directly. Many researchers have evaluated the sense of contact with wood subjectively. Ha rada et al.1 and others r epor ted the relat ions be tween the thermal proper t ies and sensory warmth of wood surfaces. Okaj ima et al. 2-7 and others have repor ted the relat ions be tween the sense of contact and the physical proper t ies of some materials. However , the sense of contact with wood has not been evaluated by physioIogical response. This study clarifies the effect of contact with wood on the human body by measuring b lood pressure and pulse continuously.

Physiological and psychological responses to prolonged light floor-impact sounds generated by a tapping machine in a wooden house

We investigated the physiological and psychological responses of nine normal men to the prolonged light floor-impact sounds of 60 dBA and 80 dBA generated by a tapping machine in a two-story wooden house. Blood pressure was measured, and a sensory evaluation was also conducted using the semantic differential method. The results obtained were as follows: (1) the increase in systolic blood pressure immediately after exposure to the light floor-impact sounds depended on the level of the sounds, (2) the variations in feelings due to the prolonged light floor-impact sounds were identified by factor analysis, and (3) the subjects showed no difference in “comfortable” feeling for the prolonged light floor-impact sounds of 60 dBA and 80 dBA, but differences in the variation of the systolic blood pressure were detected.

Effects of Milk Casein-derived Peptides on Absolute Oxyhaemoglobin Concentrations in the Prefrontal Area and on Work Efficiency after Mental Stress Loading in Male Students

This study examined the influence of milk casein-derived peptides on cerebral activity after mental stress loading. In a crossover study, 16 male students were given a drink containing peptides (peptide group), or water (control group) before stress loading. The oxyhaemoglobin (HbO2) concentration in the prefrontal area of the brain and work efficiency were measured as indicators of cerebral activity and differences in these parameters were examined according to type A or type B personality. Type A behaviour was defined as: aggression–hostility, hard-driving—time-urgency and speed–power, whereas type B behaviour did not have these characteristics. Peptide intake resulted in a significant increase in both HbO2 concentration and work efficiency, whilst a similar increase was not seen in the control group. When divided into type A or type B personality, the changes in HbO2 concentration for the control group differed significantly in the right prefrontal area. Moreover, in type A subjects the HbO2 concentration in the right prefrontal area following intake was significantly different between the peptide and control groups.

Estimating Service Life Based on the Sound Insulation Performance of Wood Sound Barriers Using an Accelerated Deterioration Test

It is necessary to estimate acoustic decline caused by rot to maintain wood sound barriers for the long term. We tried to estimate the life of the wood sound barriers by conducting a fungus cellar test to perform accelerated deterioration of small specimens with specifications equivalent to real wood sound barriers as well as measuring sound transmission losses using a small anechoic box. The sound transmission losses of untreated specimens were all less than the standard value provided by the sound barrier regulation for Japanese expressways 24 months after the accelerated deterioration test started. Conversely, the sound transmission losses of specimens treated with preservatives still exceeded the standard value mentioned above 42 months after the test started. Because the rate of deterioration of wood specimens in the fungus cellar test is considered about 6 times that in an outdoor condition, the service life of preservative-treated wood sound barriers can be estimated as at least 20 years.