Reproductive factors, genetic susceptibility and risk of type 2 diabetes: A prospective cohort study.

AIM: To explore the relationships of multiple reproductive factors with type 2 diabetes mellitus (T2DM) risk and the joint effects of reproductive factors and genetic susceptibility. METHODS: We included 262,368 women without prevalent T2DM from the UK biobank. Cox proportional hazards regression models were employed to estimate the relationships of reproductive factors with T2DM risk and the joint effects of reproductive factors and genetic susceptibility. RESULTS: During a mean follow-up of 12.2 years, 8,996 T2DM cases were identified. Early menarche (<12 years, hazard ratio (HR) 1.08 [95 % confidence interval (CI) 1.02;1.13]), late menarche (≥15 years, HR 1.11 [1.04;1.17]), early menopause (<45 years, HR 1.20 [1.12;1.29]), short reproductive lifespan (<30 years, HR 1.25 [1.16;1.35]), hysterectomy (1.31, HR [1.23;1.40]), oophorectomy (HR 1.28 [1.20;1.36]), high parity (≥4, HR 1.25 [1.17;1.34]), early age at first live birth (<20 years, HR 1.23 [1.16;1.31]), miscarriage (HR 1.13 [1.07;1.19]), stillbirth (HR 1.14 [1.03;1.27]), and ever used hormonal replacement therapy (HR 1.19 [1.14;1.24]) were related to a higher T2DM risk, while ever used oral contraceptives (HR 0.93 [0.89;0.98]) was related to a lower T2DM risk. Furthermore, women with reproductive risk factors and high genetic risk had the highest T2DM risk compared to those with low genetic risk and without reproductive risk factors. CONCLUSION: Our findings show that multiple reproductive factors are related to T2DM risk, particularly in women with high genetic risk.

Association of exposure to multiple metals with hemoglobin levels in Chinese children and adolescents.

BACKGROUND: Previous studies have linked single metal to hemoglobin levels in children and adolescents; however, studies with regards to metal mixtures are still limited. OBJECTIVE: We aimed to investigate the associations of single metal and metal mixtures with hemoglobin levels in children and adolescents. METHODS: We conducted a cross-sectional study of 2064 children and adolescents aged 6 to 19 years in Liuzhou, China in 2018. The concentrations of 15 metals in urine were determined by inductively coupled plasma mass spectrometry. Generalized linear regression and weighted quantile sum (WQS) regression were used to estimate the associations of single metal and metal mixtures with hemoglobin levels, respectively. RESULTS: The multivariable-adjusted ß-values for the highest versus the first quartiles of urinary metal concentrations were - 1.57 (95 % confidence interval [CI]: -3.01, -0.13) for chromium, -2.47 (95 % CI: -3.90, -1.05) for nickel and 1.88 (95 % CI: 0.49, 3.28) for copper. In addition, we found a significant negative association between the WQS index and hemoglobin levels (adjusted ß = -0.93, 95 % CI: -1.69, -0.19), with nickel contributing the most to the WQS index at 59.0 %. Subgroup analyses showed that exposure to urinary nickel or metal mixtures were associated with decreased hemoglobin levels in adolescents, but not in children (all Pinteration < 0.001). CONCLUSION: Among children and adolescents, urinary chromium and nickel concentrations were associated with decreased hemoglobin levels, while copper showed a positive relationship. Moreover, a negative association was observed between exposure to metal mixtures and hemoglobin levels. These findings need to be further validated in prospective studies.

Association between essential metals, adherence to healthy lifestyle behavior, and ankle-brachial index.

BACKGROUND: Ankle-brachial index (ABI) is a noninvasive diagnostic method for peripheral arterial disease (PAD) and a predictor of cardiovascular events. OBJECTIVE: The present study aimed to evaluate the association between individual or combined essential metals and ABI, as well as assess the collective impact of essential metals when coupled with healthy lifestyle on ABI. METHODS: A total of 2865 participants were recruited in Wuhan Tongji Hospital between August 2018 and March 2019. Concentrations of essential metals in urine were measured by inductively coupled plasma mass spectrometer. RESULTS: The results of general linear regression models demonstrated that after adjusting for confounding factors, there was a positive association between ABI increase and per unit increase of log 10-transformed, creatinine-corrected urinary Cr (ß (95 % CI): 0.010 (0.004, 0.016), PFDR = 0.007), Fe (ß (95 % CI): 0.010 (0.003, 0.017), PFDR = 0.018), and Co (ß (95 % CI): 0.013 (0.005, 0.021), PFDR = 0.007). The WQS regression revealed a positive relationship between the mixture of essential metals and ABI (ß (95 % CI): 0.006 (0.003, 0.010), P < 0.001), with Cr and Co contributing most to the relationship (weighted 45.48 % and 40.14 %, respectively). Compared to individuals with unfavorable lifestyle and the lowest quartile of Cr, Fe and Co, those with favorable lifestyle and the highest quartile of Cr, Fe and Co exhibited the most increase in ABI (ß (95 % CI): 0.030 (0.017, 0.044) for Cr, ß (95 % CI): 0.027 (0.013, 0.040) for Fe, and ß (95 % CI): 0.030 (0.016, 0.044) for Co). CONCLUSION: In summary, our study indicates that adequate essential metal intake together with healthy lifestyle behaviors perform crucial roles in PAD protection.

Association between hemoglobin A1c trajectory during pregnancy and adverse birth outcomes among non-gestational diabetic women.

AIMS: Previous studies have shown that higher hemoglobin A1c (HbA1c) levels within the normal range during pregnancy can increase the risk of adverse birth outcomes. However, the effects of the longitudinal HbA1c trajectory during pregnancy on adverse birth outcomes among non-gestational diabetic women are poorly characterized. We aimed to identify HbA1c trajectory during pregnancy among non-gestational diabetic women and to estimate their associations with adverse birth outcomes. METHODS: Data was extracted from the Information System of Guangdong Women and Children Hospital, China, from January 2017 to July 2022. This study involved 13,979 women who did not have gestational diabetes mellitus and underwent repeated HbA1c measurements during pregnancy. Latent mixture modeling was used to identify HbA1c trajectory groups. Logistic regression was applied to explore the associations between HbA1c trajectory groups and adverse birth outcomes, including preterm delivery, low birth weight, macrosomia, small for gestational age, and large for gestational age (LGA). RESULTS: Three HbA1c trajectory groups were identified: low-stable (range 4.0% [20 mmol/mol]-4.4% [25 mmol/mol]), moderate-stable (range 4.6% [27 mmol/mol]-5.1% [32 mmol/mol]), and elevated-increasing (range 5.0% [31 mmol/mol]-5.6% [38 mmol/mol]). Compared with the low-stable HbA1c group, the elevated-increasing group had a higher risk of preterm delivery and LGA. The adjusted OR (95% CIs) were 1.67 (1.13, 2.49) and 1.47 (1.01, 2.12) for preterm delivery and LGA, respectively. CONCLUSIONS: Among non-gestational diabetic women, the elevated-increasing HbA1c trajectory group was associated with a higher risk of preterm delivery and LGA. This finding emphasizes the importance of maintaining optimal HbA1c levels throughout pregnancy.

Exposure to organochlorine pesticides and polychlorinated biphenyls, adherence to an ideal cardiovascular health, and arterial stiffness among Chinese adults.

This study aimed to assess the relationships between exposure to individual organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and their mixture and arterial stiffness and explore whether adherence to an ideal cardiovascular health (CVH) could mitigate these associations. The cross-sectional study enrolled 1437 Chinese adults between March and May 2019 in Wuhan, China. OCPs and PCBs concentrations were measured using solid phase extraction coupled with gas chromatography-tandem mass spectrometry. Arterial stiffness was evaluated by brachial-ankle pulse wave velocity (baPWV). CVH was determined by three behavioral and four biological metrics and categorized as ideal, intermediate, and poor CVH. We applied generalized linear model and weighted quantile sum (WQS) regression to evaluate the associations of exposure to individual OCPs or PCBs and their mixture with baPWV, respectively. We found that participants with detectable levels of heptachlor epoxide, PCB-153, and PCB-180 had higher baPWV (ß: 34.25, 95% CI 14.28-54.22; ß: 27.64, 95% CI 7.90-47.38; and ß: 30.51, 95% CI 10.68-50.35) than those with undetectable levels. In WQS regression, the mixture of OCPs and PCBs was related to a higher baPWV (ß: 24.93, 95% CI 2.70-47.15). Compared with participants with ideal CVH and undetectable OCPs or PCBs levels, those with poor CVH and detectable OCPs or PCBs levels had the highest increase in baPWV (heptachlor epoxide: ß: 147.94, 95% CI 112.52-183.55; PCB-153: ß: 150.22, 95% CI 115.40-185.04; PCB-180: ß: 147.02, 95% CI 111.66-182.38). Our findings suggested that individual OCPs, PCBs, and their mixture exposure were positively associated with arterial stiffness, and adherence to an ideal CVH may mitigate the adverse effect.

Association of prenatal essential metal exposure with newborn mitochondrial DNA copy number: Results from a birth cohort study.

Imbalance or deficiencies of essential metals can lead to oxidative stress, that can damage mitochondrial DNA (mtDNA) molecule. Knowledge on effects of exposure to essential metals and their mixture remains limited. We aimed to evaluate individual and joint associations of prenatal essential metals with neonatal mtDNA copy number. We recruited 746 mother-newborn pairs from a birth cohort study conducted in Wuhan City, China, and collected trimester-specific urine and cord blood samples. We measured the concentrations of seven urinary essential metals, include zinc (Zn), iron (Fe), selenium (Se), cobalt (Co), manganese (Mn), copper (Cu), and chromium (Cr), using inductively coupled plasma mass spectrometry, and measured cord blood mtDNA copy number using real-time quantitative polymerase chain reaction. We estimated the trimester-specific associations of individual essential metal concentrations with mtDNA copy number using a multiple informant model, and assessed their joint association using weighted quantile sum (WQS) regression. For individual essential metal, a doubling of maternal urinary Zn concentrations during the second trimester was associated with a 7.47% (95% CI: 1.17-14.17%) higher level of neonatal mtDNA copy number. For the essential metal mixture, one-unit increased in the WQS index of the essential metals mixture during the second trimester resulted in a 10.41% (95% CI: 3.04-18.30%) increase in neonatal mtDNA copy number. Our findings suggest that exposure to both Zn and essential metal mixture during the second trimester is associated with a higher neonatal mtDNA copy number. Further research should assess whether mtDNA copy number is associated with child health.

Associations of polychlorinated biphenyl and organochlorine pesticide exposure with hyperuricemia: modification by lifestyle factors.

Recent research has reported positive associations of exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) with hyperuricemia. However, most of these studies have primarily focused on the individual effects of PCB/OCP exposure. We aimed to explore the associations of both individual and combined PCB/OCP exposure with hyperuricemia and examine whether such associations could be modified by lifestyle factors. The cross-sectional study recruited 2032 adults between March and May 2019 in Wuhan, China. Logistic regression and weighted quantile sum (WQS) regression were applied to explore the relationship of individual and combined PCB/OCP exposure with hyperuricemia, while considering the modified effects of lifestyle factors. Of the 2032 participants, 522 (25.7%) had hyperuricemia. Compared with the non-detected group, the detected groups of PCB153 and PCB180 exhibited a positive association with hyperuricemia, with OR (95% CIs) of 1.52 (1.22, 1.91) and 1.51 (1.20, 1.90), respectively. WQS regression showed that PCB/OCP mixture was positively associated with hyperuricemia (OR: 1.31, 95% CI: 1.08, 1.58). PCB153/PCB180 exposure, combined with an unhealthy lifestyle, has a significant additive effect on hyperuricemia. Overall, PCB/OCP mixture and individual PCB153/PCB180 exposure were positively associated with hyperuricemia. Adherence to a healthy lifestyle may modify the potential negative impact of PCBs/OCPs on hyperuricemia.

Association between female-specific reproductive factors and leukocyte telomere length.

STUDY QUESTION: What are the associations between female-specific reproductive factors and leukocyte telomere length (LTL)? SUMMARY ANSWER: Early menarche, early menopause, short reproductive lifespan, early age at first birth, multiparity, and use of oral contraceptives (OCs) and hormone replacement therapy (HRT) were associated with shorter LTL. WHAT IS KNOWN ALREADY: Reproductive factors have been associated with age-related diseases, but their associations with cellular aging, as indicated by LTL, are unclear. STUDY DESIGN, SIZE, DURATION: This population-based study included 224 965 women aged 40-69 years from the UK Biobank between 2006 and 2010. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women aged 40-69 were included. Female-specific reproductive factors, including age at menarche, age at natural menopause, reproductive lifespan, number of live births, age at first live birth, history of stillbirth, history of miscarriage, and use of OCs and HRT were self-reported. LTL was measured using a validated polymerase chain reaction method. Multiple linear regression and restricted cubic spline models were applied to explore the association between each reproductive factor and LTL. MAIN RESULTS AND THE ROLE OF CHANCE: After adjustment for potential confounders, early menarche (<12 years; percent change, per unit change in LTL Z score: -1.29%, 95% CI: -2.32%, -0.26%), early menopause (<45 years; percent change: -7.18%, 95% CI: -8.87%, -5.45%), short reproductive lifespan (<30 years; percent change: -6.10%, 95% CI: -8.14%, -4.01%), multiparity (percent change: -3.38%, 95% CI: -4.38%, -2.37%), early age at first live birth (<20 years; percent change: -4.46%, 95% CI: -6.00%, -2.90%), and use of OCs (percent change: -1.10%, 95% CI: -2.18%, -0.02%) and HRT (percent change: -3.72%, 95% CI: -4.63%, -2.80%) were all significantly associated with shorter LTL. However, no significant association was found for history of miscarriage and stillbirth. We observed nonlinear relationships of age at menarche, age at natural menopause, reproductive lifespan, and age at first live birth with LTL (Pnonlinear < 0.05). LIMITATIONS, REASONS FOR CAUTION: Considering that the participants were predominantly of European ethnicity, the findings may not be generalizable to women of other ethnic backgrounds. WIDER IMPLICATIONS OF THE FINDINGS: Our findings suggest that early menarche, early menopause, short reproductive lifespan, early age at first birth, multiparity, and use of OCs and HRT were associated with shorter LTL, which has been linked to various chronic diseases. The accelerated shortening of telomeres may potentially contribute to the development of chronic diseases related to reproductive factors. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the National Natural Science Foundation of China (82003479, 82073660), Hubei Provincial Natural Science Foundation of China (2023AFB663), and the China Postdoctoral Science Foundation (2019M662646, 2020T130220). The authors have no competing interests to disclose. TRIAL REGISTRATION NUMBER: N/A.

Associations of self-reported sleep duration and sleep quality during pregnancy with newborn telomere length.

BACKGROUND: Telomere length (TL) at birth is considered a potential biomarker for lifelong health. Although maternal sleep disturbance has been linked to a series of adverse pregnancy outcomes, evidence on the effect of maternal sleep on newborn TL remains scarce. Therefore, we aim to investigate the association of maternal sleep duration and sleep quality with newborn TL. METHODS: A total of 742 mother-newborn pairs were recruited from Wuhan Children's Hospital between November 2013 and March 2015. Cord blood TL was measured using real-time quantitative polymerase chain reaction. Maternal sleep duration and quality during late pregnancy were obtained via questionnaires. Multivariate linear regression models were used to estimate the effects of maternal sleep duration and sleep quality on newborn TL. RESULTS: A total of 742 maternal-newborn pairs were included in the analyses. Mothers sleeping ≥10 hours had a 9.30% (95% CI: 2.09%, 15.99%) shorter newborn TL than those sleeping 7-<9 hours. However, the association in mothers with short sleep duration (<7 hours) did not reach statistical significance. Compared to mothers with good sleep quality, those with poor sleep quality had a 9.91% (95% CI: 4.06%, 15.40%) shorter newborn TL. We observed a joint effect of sleep duration and sleep quality on newborn telomere shortening. Women with sleep duration ≥10 hours and poor sleep quality were most likely to have newborns with short TL (percent change:-19.66%, 95% CI: -28.42, -9.84%). CONCLUSIONS: Long sleep duration and poor sleep quality during late pregnancy were associated with shorter newborn TL.

Sex-specific associations of single metal and metal mixture with handgrip strength: a cross-sectional study among Chinese adults.

Metallic elements are ubiquitous in the natural environment and always collaborate to affect human health. The relationship of handgrip strength, a marker of functional ability or disability, with metal co-exposure remains vague. In this study, we aimed to investigate the effect of metal co-exposure on sex-specific handgrip strength. A total of 3594 participants (2296 men and 1298 women) aged 21 to 79 years recruited from Tongji Hospital were included in the present study. Urinary concentrations of 21 metals were measured by inductively coupled plasma mass spectrometer (ICP-MS). We used linear regression, restricted cubic spline (RCS) model, and weighted quantile sum (WQS) regression to evaluate the association of single metal as well as metal mixture with handgrip strength. After adjusting for important confounding factors, the results of linear regression showed that vanadium (V), zinc (Zn), arsenic (As), rubidium (Rb), cadmium (Cd), thallium (Tl), and uranium (U) were adversely associated with handgrip strength in men. The results of RCS showed a non-linear association between selenium (Se), silver (Ag), and nickel (Ni) with handgrip strength in women. The results of WQS regression revealed that metal co-exposure was inversely related to handgrip strength for men (ß = -0.65, 95% CI: -0.98, -0.32). Cd was the critical metal in men (weighted 0.33). In conclusion, co-exposure to a higher level of metals is associated with lower handgrip strength, especially among men, and Cd may contribute most to the conjunct risk.

Association of metal exposure with arterial stiffness in Chinese adults.

BACKGROUND: Arterial stiffness is an important indicator of cardiovascular aging. However, studies assessing the association between metal exposure and arterial stiffness are limited. OBJECTIVE: The aim of this study was to investigate the independent and joint associations of metal exposure with arterial stiffness. METHODS: This cross-sectional study recruited 2982 Chinese adults from August 2018 to March 2019 in Wuhan, China. The concentrations of 20 urinary metals were determined using inductively coupled plasma mass spectrometer. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV). We used generalized linear model (GLM) to estimate the association of single metal exposure with baPWV. We used weighted quantile sum (WQS) regression to estimate the association of metal mixture with baPWV. RESULTS: In GLM regression analysis, each doubling of urinary copper (Cu) and chromium (Cr) concentrations were associated with 6.48 (95 % CI: 2.51-10.45) cm/s and 3.78 (95 % CI: 0.42-7.14) cm/s increase in baPWV, respectively. In WQS regression analysis, each unit increase in WQS index of the metal mixture was associated with a 9.10 (95 % CI: 2.39-15.82) cm/s increase in baPWV. Cu, Zn, and Cr were the dominant urinary metals associated with baPWV. CONCLUSION: Metal exposure, both individually and in mixture, was associated with an increased risk of arterial stiffness. Our findings may provide a target for preventative strategies against cardiovascular aging.

Behavioral and electrophysiological evidence for the flexible recruitment of feature- and object-based processing in visual working memory comparison.

Previous research is inconclusive on when visual working memory (VWM) can be object-based or feature-based. Prior event-related potential (ERP) studies using change detection tasks have found that amplitudes of the N200-an ERP index of VWM comparison- are sensitive to changes in both relevant and irrelevant features, suggesting a bias toward object-based processing. To test whether VWM comparison processing can operate in a feature-based manner, we aimed to create circumstances that would support feature-based processing by: 1) using a strong task-relevance manipulation, and 2) repeating features within a display. Participants completed two blocks of a change detection task for four-item displays in which they were told to respond to color changes (task relevant) but not shape changes (task irrelevant). The first block contained only task-relevant changes to create a strong task-relevance manipulation. In the second block, both relevant and irrelevant changes were present. In both blocks, half of the arrays contained within-display feature repetitions (e.g. two items of the same color or shape). We found that during the second block, N200 amplitudes were sensitive to task-relevant but not irrelevant features regardless of repetition status, consistent with feature-based processing. However, analyses of behavioral data and N200 latencies suggested that object-based processing was occurring at some stages of VWM processing on task-irrelevant feature change trials. In particular, task-irrelevant changes may be processed after no task-relevant feature change is revealed. Overall, the results from the current study suggest that the VWM processing is flexible and can be either object- or feature-based.

Exposure to Metal Mixtures and Overweight or Obesity Among Chinese Adults.

Previous research has investigated the association between individual metal exposure and overweight/obesity (OW/OB). However, there is limited data about metal mixture exposure and OW/OB. This study aimed to explore the individual and joint effects of 21 metals on OW/OB and its metabolic phenotypes. A total of 4042 participants were enrolled in our study, and 51.0% of them were overweight/obese. We quantified 21 metal levels in the urine sample. OW/OB was defined as BMI ≥ 24 kg/m2, while the metabolic phenotypes, including metabolic unhealthy overweight/obesity (MUOW/OB) and metabolic health overweight/obesity (MHOW/OB), were determined by BMI and metabolic state. We used logistic regression to analyze the effect of individual metal exposure on OW/OB and its metabolic phenotypes. Quantile g-computation was applied to evaluate the joint effect of metal exposure on OW/OB and its metabolic phenotypes. In logistic regression, zinc (Zn) was positively associated with OW/OB, with the odds ratio (OR) in the highest quartiles of 2.19 (95% confidence interval (CI), 1.74, 2.77; P trend < 0.001), while arsenic (As) and cadmium (Cd) were negatively associated with OW/OB (OR = 0.70 (0.56, 0.87) and 0.61 (0.48, 0.78), respectively). After adjustment for age, gender, education, cigarette smoking, alcohol drinking, physical activity, meat intake, and vegetable intake, Zn was positively associated with MUOW/OB, while As, Cd, nickel (Ni), and strontium (Sr) were negatively associated with MUOW/OB (all P trend < 0.05). Quantile g-computation showed a significantly negative association between metal mixture exposure and MUOW/OB. Our study suggested that metal mixture exposure might be negatively associated with OW/OB, particularly with MUOW/OB. Zn, As and Cd contributed most to the effect of the mixture. More prospective studies are warranted to confirm these findings and reveal the underlying mechanisms.

Association of maternal folic acid supplementation during pregnancy with newborn telomere length.

This study aimed to explore the associations between maternal folic acid (FA) supplementation during different trimesters of pregnancy and newborn telomere length (TL). Data were collected from a birth cohort study of 746 mother-newborn pairs conducted from November 2013 to March 2015 in Wuhan, China. After adjustment for potential confounders, maternal FA supplementation after the first trimester and throughout pregnancy were associated with longer newborn TL [ß = 0.29, 95 % confidence interval (CI): 0.20, 0.38 and ß = 0.24, 95 % CI: 0.16, 0.32, respectively]. No significant association was found between maternal FA supplementation in the first trimester and newborn TL. In conclusion, a possible association between maternal FA supplementation during pregnancy with longer newborn TL was suggested in the present study. This study provides insight into the benefit of newborn TL by maternal FA supplementation during pregnancy.

Individual Differences in Cognitive Constructs: A Comparison Between American and Chinese Culture Groups.

Previous studies on human cognition show that people with different cultural backgrounds may differ in various ways. However, there are other unexplored possibilities for cultural differences including degree of handedness thought to reflect hemispheric coordination, reliance on verbal versus visual representation in problem solving, and working memory capacity both spatial and operational. We assessed each of these using the Edinburgh scale, a validated scale of style of processing, and two automatic working memory span tasks. Participants were either native Chinese students (who spoke Mandarin) or American students. Data showed that culture impacted the set of measures but gender did not and these factors did not interact. Chinese and American students showed the largest difference in their operational working memory. We also examined the pattern of correlations among the measures across the two groups and found differences due to cultural group as well.

Catching a Liar Through Facial Expression of Fear.

High stakes can be stressful whether one is telling the truth or lying. However, liars can feel extra fear from worrying to be discovered than truth-tellers, and according to the "leakage theory," the fear is almost impossible to be repressed. Therefore, we assumed that analyzing the facial expression of fear could reveal deceits. Detecting and analyzing the subtle leaked fear facial expressions is a challenging task for laypeople. It is, however, a relatively easy job for computer vision and machine learning. To test the hypothesis, we analyzed video clips from a game show "The moment of truth" by using OpenFace (for outputting the Action Units (AUs) of fear and face landmarks) and WEKA (for classifying the video clips in which the players were lying or telling the truth). The results showed that some algorithms achieved an accuracy of >80% merely using AUs of fear. Besides, the total duration of AU20 of fear was found to be shorter under the lying condition than that from the truth-telling condition. Further analysis found that the reason for a shorter duration in the lying condition was that the time window from peak to offset of AU20 under the lying condition was less than that under the truth-telling condition. The results also showed that facial movements around the eyes were more asymmetrical when people are telling lies. All the results suggested that facial clues can be used to detect deception, and fear could be a cue for distinguishing liars from truth-tellers.

Neural correlates of heat-evoked pain memory in humans.

The neural processes underlying pain memory are not well understood. To explore these processes, contact heat-evoked potentials (CHEPs) were recorded in humans with electroencephalography (EEG) technique during a delayed matching-to-sample task, a working memory task involving presentations of two successive painful heat stimuli (S-1 and S-2) with different intensities separated by a 2-s interval (the memorization period). At the end of the task, the subject was required to discriminate the stimuli by indicating which (S-1 or S-2) induced more pain. A control task was used, in which no active discrimination was required between stimuli. All event-related potential (ERP) analysis was aligned to the onset of S-1. EEG activity exhibited two successive CHEPs: an N2-P2 complex (∼400 ms after onset of S-1) and an ultralate component (ULC, ∼900 ms). The amplitude of the N2-P2 at vertex, but not the ULC, was significantly correlated with stimulus intensity in these two tasks, suggesting that the N2-P2 represents neural coding of pain intensity. A late negative component (LNC) in the frontal recording region was observed only in the memory task during a 500-ms period before onset of S-2. LNC amplitude differed between stimulus intensities and exhibited significant correlations with the N2-P2 complex. These indicate that the frontal LNC is involved in maintenance of intensity of pain in working memory. Furthermore, alpha-band oscillations observed in parietal recording regions during the late delay displayed significant power differences between tasks. This study provides in the temporal domain previously unidentified neural evidence showing the neural processes involved in working memory of painful stimuli.