Journal of Physiological Anthropology最新文献

Here, we review the history and the trends in the research on the nonvisual effect of light in the field of physiological anthropology. Research on the nonvisual effect of light in the field of physiological anthropology was pioneered by Sato and colleagues in the early 1990s. These authors found that the color temperature of light affected physiological functions in humans. The groundbreaking event with regard to the study of nonvisual effects of light was the discovery of the intrinsically photosensitive retinal ganglion cells in the mammalian retina in the early 2000s. The interest of the physiological anthropology scientific community in the nonvisual effects of light has been increasing since then. A total of 61 papers on nonvisual effects of light were published in the Journal of Physiological Anthropology (including its predecessor journals) until October 2018, 14 papers (1.4/year) in the decade from 1992 to 2001, 45 papers (2.8/year) in the 16 years between 2002 and 2017, and two papers in 2018 (January-October). The number of papers on this topic has been increasing in recent years. We categorized all papers according to light conditions, such as color temperature of light, light intensity, and monochromatic light. Among the 61 papers, 11 papers were related to color temperature, 20 papers were related to light intensity, 18 papers were related to monochromatic light, and 12 papers were classified as others. We provide an overview of these papers and mention future research prospects.

Background: It is known that the activities of the mirror system are related to imitation and understanding of the intention of an action. It has been reported that the activity of the mirror system is higher for observations for imitating and understanding the intention of an action than for simple observations. However, observations that facilitate the mirror system's activities, if they are observations intending to imitate an action or observations for understanding the intention of an action, have not been clarified to date.

Methods: The types of observations of actions that highly facilitate mirror system activities were investigated. Participants were right-handed university students (N = 23). They observed videos showing hand actions following three types of instructions: (1) to observe the videos intending to understand the intention of the action (action understanding, AU), to observe the videos intending to imitate the hand action (imaginarily imitation, II), and to observe the videos without any intention (observation, OB). Brain waves during observation were measured, and the suppression rate of 8-10 Hz (lower mu/α) and 10-12 Hz (upper mu/α) in the central and occipital regions of the brain was calculated. The rate of suppression was compared among the conditions using a repeated measures analysis of variance for each region.

Results: There was a main effect of the condition in the central region in 10-12 Hz. The degree of suppression in the AU condition was significantly larger than SO condition (p < 0.05) and II condition (p < 0.1). However, there were no differences among conditions in 8-10 Hz, the occipital region, or in either frequency band.

Conclusions: These results suggest that activities of the mirror system are enhanced when observing an action with the purpose of understanding the intention of the action. Differences in the mirror system activities according to the changes of inner states might be better reflected in high-frequency mu waves.

After the publication of the original article [1] it was highlighted that there was an omission regarding the online resources for the traffic signs in the section of "Experimental stimuli".

Background: It is well known that light containing the blue component stimulates the intrinsically photosensitive retinal ganglion cells (ipRGCs) and plays a role in melatonin suppression and pupillary constriction. In our previous studies, we verified that simultaneous exposure to blue and green light resulted in less pupillary constriction than blue light exposure. Hence, we hypothesized that the nonvisual effects of polychromatic white light might be increased by blocking the green component. Therefore, we conducted an experiment using optical filters that blocked blue or green component and examined the nonvisual effects of these lights on pupillary constriction and electroencephalogram power spectra.

Methods: Ten healthy young males participated in this study. The participant sat on a chair with his eyes facing an integrating sphere. After 10 min of light adaptation, the participant's left eye was exposed to white pulsed light (1000 lx; pulse width 2.5 ms) every 10 s with a blue-blocking glasses, a green-blocking glasses, or control glasses (no lens), and pupillary constriction was measured. Then, after rest for 10 min, the participant was exposed a continuous white light of 1000 lx with a blue- or green-blocking glasses or control glasses and electroencephalogram was measured.

Results: Pupillary constriction with the blue-blocking glasses was significantly less than that observed with the green-blocking glasses. Furthermore, pupillary constriction under the green-blocking glasses was significantly greater than that observed with the control glasses.

Conclusions: A reduction in the green component of light facilitated pupillary constriction. Thus, the effects of polychromatic white light containing blue and green components on ipRGCs are apparently increased by removing the green component.

Background: Previous research on balance mostly focused on the assessment, training, and improvements of balance through interventions. We investigated tools commonly used to study static balance. Differences in postural stability were analyzed using multiscale entropy (MSE) and feature analysis.

Methods: A force plate and inertial sensor were used to collect acceleration and center-of-pressure (COP) nonlinear signals. MSE was also used to detect fractal correlations and assess the complexity of univariate data complexity. Fifteen healthy subjects participated in the experiments. Each stood on a force plate and wore a sensor while attempting to maintain postural stability for 30 s in four randomized experiments to evaluate their static balance via a copositive experiment with eyes open/closed and with standing on one foot or both feet. A Wilcoxon-signed rank test was used to confirm that the conditions were significant. Considering the effect of the assessment tools, the influence of the visual and lower limb systems on postural stability was assessed and the results from the inertial sensor and force plate experiments were compared.

Results: Force plate usage provided more accurate readings when completing static balance tasks based on the visual system, whereas an inertial sensor was preferred for lower-limb tasks. Further, the eyes-open-standing-on-one-foot case involved the highest complexity at the X, Y, and Z axes for acceleration and at the ML axis for COP compared with other conditions, from which the axial directions can be identified.

Conclusions: The findings suggested investigation of different evaluation tool choices that can be easily adapted to suit different needs. The results for the complexity index and traditional balance indicators were comparable in their implications on different conditions. We used MSE to determine the equipment that measures the postural stability performance. We attempted to generalize the applications of complexity index to tasks and training characteristics and explore different tools to obtain different results.

Trial registration: This study was approved by the Research Ethics Committee of National Taiwan University and classified as expedited on August 24, 2017. The committee is organized under and operates in accordance with Social and Behavioral Research Ethical Principles and Regulations of National Taiwan University and government laws and regulations.

Background: Immigration is a disruptive event with multiple implications for health. Stressors, including family separation, acculturation, job insecurity, restricted mobility, sojourns, dangerous border crossings, stigmatization, and marginalization, shape immigrant health in ways we are only beginning to untangle. Around the world, there are over 200 million international migrants. In 2015, there were 43.2 million immigrants living in the US, 26.8% of whom were born in Mexico. Investigating how stress affects health among migrants facilitates better understanding of their experiences.

Methods: Here, we review existing research on stress and how allostatic load varies among migrants with specific attention to Mexican migrants in the US. Next, we explore research incorporating biomarkers of allostasis and narratives of migration and settlement to examine disease risks of Mexican migrants residing in Columbus, Ohio. This mixed-methods approach allowed us to examine how social stressors may influence self-reports of health differentially from associations with assessed discrimination and physiological biomarkers of health.

Results: These data sources are not significantly associated. Neither narratives nor self-reports of health provide significant proxies for participants' physiological health.

Conclusions: We propose, the pairing of objectively assessed health profiles with narratives of migration better illustrate risks migrants face, while allowing us to discern pathways through which future health challenges may arise. Immigration and acculturation to a new nation are biologically and culturally embedded processes, as are stress and allostatic responses. To understand how the former covary with the latter requires a mixed-methods bioethnographic approach. Differences across multiple social and physiological systems, affect individual health over time. We propose incorporating physiological biomarkers and allostatic load with migrants' narratives of their migration to unravel complex relationships between acculturation and health.

Background: Measurements of erect height in older people, hospitalized and bedridden patients, and people with skeletal deformity is difficult. As a result, using body mass index for assessing nutritional status is not valid. Height estimated from linear body measurements such as arm span, knee height, and half arm span was shown to be useful surrogate measures of stature. However, the relationship between linear body measurements and stature varies across populations implying the need for the development of population-specific prediction equation. The objective of this study was to develop a formula that predicts height from arm span, half arm span, and knee height for Ethiopian adults and assess its agreement with measured height.

Methods: A cross-sectional study was conducted from March 15 to April 21, 2016 in Jimma University among a total of 660 (330 females and 330 males) subjects aged 18-40 years. A two-stage sampling procedure was employed to select study participants. Data were collected using interviewer-administered questionnaire and measurement of anthropometric parameters. The data were edited and entered into Epi Data version 3.1 and exported to SPSS for windows version 20 for cleaning and analyses. Linear regression model was fitted to predict height from knee height, half arm span, and arm span. Bland-Altman analysis was employed to see the agreement between actual height and predicted heights. P values < 0.05 was used to declare as statistically significance.

Results: On multivariable linear regression analyses after adjusting for age and sex, arm span (β = 0.63, p < 0.001, R² = 87%), half arm span (β = 1.05, p < 0.001, R² = 83%), and knee height (β = 1.62, p < 0.001, R² = 84%) predicted height significantly. The Bland-Altman analyses showed a good agreement between measured height and predicted height using all the three linear body measurements.

Conclusion: The findings imply that in the context where height cannot be measured, height predicted from arm span, half arm span, and knee height is a valid proxy indicator of height. Arm span was found to be the best predictor of height. The prediction equations can be used to assess the nutritional status of hospitalized and/or bedridden patients, people with skeletal deformity, and elderly population in Ethiopia.

Background: Although the benefits of physical activity are well-known, levels of physical inactivity are increasing in many countries. Physical activity, particularly for preventive care of the elderly, must be encouraged. The level of physical activity undertaken by people is influenced by season; however, little is known about seasonal fluctuations of physical activity and its relation to muscle strength/mass. Consequently, we clarified the association between physical activity levels and muscle strength/skeletal muscle mass during non-snowy and snowy seasons in northern Japan.

Methods: Participants were community-dwelling elderly people aged 65 years or older living in Tobetsu, northern Japan. A 30-s chair-stand test (CS-30) and body composition measurements using bioelectrical impedance analysis were conducted prior to physical activity measurement using a three-dimensional acceleration sensor in both non-snowy and snowy seasons. Daily steps for the non-snowy and snowy seasons were compared using Welch's t test. The association between the CS-30/skeletal muscle index and daily steps in both seasons was estimated by fitting multiple linear regression models, with age and sex as covariates.

Results: Average daily step counts were significantly lower during the snowy season, compared to the non-snowy season (P < .01). The CS-30 in the snowy season alone was significantly associated with daily step counts. Multiple linear regression analyses results revealed that, for the same muscle strength in both seasons, the daily step counts during the snowy season were fewer than those during the non-snowy season.

Conclusions: The muscle strength required to perform adequate physical activity depended on season. This study obtained basic knowledge to ensure health promotion for elderly people living in snowy-cold regions.

Background: Previous studies have demonstrated the importance of the inhibition of automatic imitation in social interactions. Additionally, cognitive traits are known to vary among individuals. According to the empathizing-systemizing (E-S) model, personality can be quantified by empathizing and systemizing drives in causal cognition. Since inhibition of automatic imitation is strongly related to social cognition, the level of inhibition may be explained by personal cognitive traits. Thus, the current study tested whether cognitive traits, measured based on the E-S model, correlated with levels of automatic imitation inhibition.

Methods: The empathizing-systemizing quotient (EQ-SQ) questionnaire was used to assess cognitive traits. Behavioral and electroencephalogram data were acquired during the imitation inhibition task. In addition to reaction time, based on signal detection theory, task sensitivity and response bias were calculated from reaction data. As a physiological measure of automatic imitation, mu rhythm power suppression was calculated from electroencephalogram data. Congruency effects for reaction time and electroencephalogram measures were calculated by subtracting congruent trials from incongruent trails.

Results: Correlation analyses between cognitive traits and task measures were conducted. There was a negative correlation found between EQ score and the behavioral index reflecting task performance. Moreover, a negative correlation was found between SQ score and the congruency effect on mu suppression.

Conclusions: Participants with higher EQ scored relatively lower in inhibiting their responses. Conversely, high SQ participants showed successful inhibition of mu suppression. The imitative tendency may disturb the inhibition of response. The correlation between SQ and mu index suggests the involvement of domain-general information processing on imitation inhibition; however, further research is required to determine this. Since different correlations were found for behavioral and physiological measures, these measures may reflect different steps of information processing for successful task execution. Through correlational analysis, a possible relation was identified between the inhibiting process of automatic imitation and personal cognitive styles on social interactions.

Background: Bright light at night is known to suppress melatonin secretion. Novel photoreceptors named intrinsically photosensitive retinal ganglion cells (ipRGCs) are mainly responsible for projecting dark/bright information to the suprachiasmatic nucleus and thus regulating the circadian system. However, it has been shown that the amplitude of the electroretinogram of ipRGCs is considerably lower under flickering light at 100 Hz than at 1-5 Hz, suggesting that flickering light may also affect the circadian system. Therefore, in this study, we evaluated light-induced melatonin suppression under flickering and non-flickering light.

Methods: Twelve male participants between the ages of 20 and 23 years (mean ± S.D. = 21.6 ± 1.5 years) were exposed to three light conditions (dim, 100-Hz flickering, and non-flickering blue light) from 1:00 A.M. to 2:30 A.M., and saliva samples were obtained just before 1:00 A.M. and at 1:15, 1:30, 2:00, and 2:30 A.M.

Results: A repeated measures t test with Bonferroni correction showed that at 1:15 A.M., melatonin concentrations were significantly lower following exposure to non-flickering light compared with dim light, whereas there was no significant difference between the dim and 100-Hz flickering light conditions. By contrast, after 1:30 A.M., the mean melatonin concentrations were significantly lower under both 100-Hz flickering and non-flickering light than under dim light.

Conclusion: Although melatonin suppression rate tended to be lower under 100-Hz flickering light than under non-flickering light at the initial 15 min of the light exposure, the present study suggests that 100-Hz flickering light may have the same impact on melatonin secretion as non-flickering light.