Persistence of metric biases in body representation during the body ownership illusion.

Our perception of the body's metric is influenced by bias according to the axis, called the systematic metric bias in body representation. Systematic metric bias was first reported as Weber's illusion and observed in several parts of the body in various patterns. However, the systematic metric bias was not observed with a fake hand under the influence of the body ownership illusion during the line length judgment task. The lack of metric bias observed during the line length judgment task with a fake hand implies that the tactile modality occupies a relatively less dominant position than perception occurring through the real body. The change in weight between visual and tactile modalities during the body ownership illusion has not been adequately investigated yet, despite being a factor that influences the perception through body ownership illusion. Therefore, this study aimed to investigate whether the dominance of vision over tactile modality is prominent, regardless of the task type. To investigate whether visual dominance persists during the process of inducing body ownership illusion regardless of task type, we introduced spatial visuotactile incongruence (2 cm, 3 cm) in the longitudinal and transverse axes during the visuotactile localization tasks and measured the intensity of the body ownership illusion using a questionnaire. The results indicated that participants perceived smaller visuotactile incongruence when the discrepancy occurred in the transverse axis rather than in the longitudinal axis. The anisotropy in the tolerance of visuotactile incongruence implies the persistence of metric biases in body representation. The results suggest the need for further research regarding the factors influencing the weight of visual and tactile modalities.

Obesity and sleep mismatch between weekends and weekdays in the Korean population according to working status.

OBJECTIVES: To investigate whether sleep mismatch between weekends and weekdays is correlated with obesity according to working status and sex in the Korean population. STUDY DESIGN: This study was conducted using data from the Korea National Health and Nutritional Examination Survey (KNHANES) in 2016. A total of 5,684 subjects (2,453 men and 3,231 women) were divided into subgroups according to age, sex and working status. Sleep mismatch was defined as the difference in sleep duration between weekdays and weekends. In this study, multivariable logistic regression analysis was applied to obtain odds ratios (ORs) for obesity in those with sleep mismatch ≥ 90 min when referenced to those with sleep mismatch < 90 min. MAIN OUTCOME MEASURES: In the working group, adjusted ORs for obesity were mostly less than 1, but they were not statistically significant among any age or sex groups. However, for the non-working group, men over 60 years of age with sleep mismatch ≥ 90 min showed significantly increased ORs when referenced to those with sleep mismatch < 90 min in every model; the OR in model 4 was 2.89. Women over 60 years of age with sleep mismatch ≥ 90 min also showed higher ORs but they were not statistically significant. CONCLUSIONS: Men who are not working and over 60 years of age in Korea may be at increased risk of obesity if their sleep mismatch is ≥ 90 min. Therefore, it might be possible to lower the prevalence of obesity in the elderly population by correcting sleep irregularity or through reemployment.

The role of interim 18F-FDG PET/CT in predicting early response to neoadjuvant chemotherapy in breast cancer.

AIM: The aim of this study was to prove the diagnostic value of interim 18F-Fluorodeoxyglucose-positron-emission tomography combined with computed tomography (PET/CT) scan for predicting pathological complete response (pCR) compared to other factors in neoadjuvant chemotherapy. PATIENTS AND METHODS: Twenty-seven patients with breast cancer were included in this retrospective study. They all underwent scheduled neoadjuvant chemotherapy. Patients underwent PET/CT at baseline, mid-point (interim), and preoperatively (after completion of chemotherapy). The metabolic response was calculated as follows: ΔStandardized uptake value (SUV)(%)=(1st SUV(max)-2nd SUV(max))/1st SUV(max) × 100. RESULTS: The change in SUVmax between baseline and interim PET/CT scans was significantly larger than between interim and preoperative PET/CT scan. An optimal cut-off ΔSUV value of 78.3% was proposed for discriminating patients with pCR from those without pCR. Metabolic CR, defined as a change of SUV(max) greater than the cut-off value, can predict pCR according to univariate analysis (p=0.012; Relative risk (RR)=25.3). Furthermore, metabolic CR was the most powerful factor for predicting pCR than other possible factors according to multivariate analysis (p=0.003). CONCLUSION: It is possible to use interim (18)F-FDG PET-CT as an effective method to predict early response in patients with breast cancer treated with neoadjuvant chemotherapy.