Researchers used cultured ovarian cancer cells to investigate the anti-cancer properties of hemp extract. Credit: Annie Wang
Sleep disturbances in girls associated with more difficulties staying awake in and out of school
June 6, 2018
Science Daily/American Academy of Sleep Medicine
Preliminary results of a recent study show that teen girls reported a higher degree of interference of daytime sleepiness on multiple aspects of their school and personal activities than boys.
The study examined whether teen boys and girls report similar negative impact of sleep disturbances on their daytime functioning.
"What was most surprising is the fact that teenage girls reported a higher degree of interference of daytime sleepiness than teenage boys on multiple aspects of their school and personal activities," said co-author Pascale Gaudreault, who is completing her doctoral degree in clinical neuropsychology under the supervision of principal investigator Dr. Geneviève Forest at the Université du Québec en Outaouais in Gatineau, Québec, Canada. "For example, teenage girls have reported missing school significantly more often than teenage boys due to tiredness, as well as reported having lower motivation in school due to a poor sleep quality."
731 adolescents (311 boys; 420 girls; ages 13 to 17.5 years; grades 9-11) completed a questionnaire about sleep and daytime functioning. Questions were answered on a seven-point Likert scale (1=never; 7=often). Gender differences were assessed using t-tests.
Study results show that teenage girls reported more difficulties staying awake during class in the morning, during class in the afternoon, and during homework hours than boys. They also reported feeling too tired to do activities with their friends, missing school because of being too tired, feeling less motivated in school because of their poor sleep, and taking naps during weekends more often than boys. However, there was no gender difference when it came to using coffee or energy drinks to compensate for daytime sleepiness or for falling asleep in class.
"These results suggest that teenage girls may be more vulnerable than teenage boys when it comes to the negative impacts of adolescence's sleep changes," said Gaudreault.
New study shows it's all about perception
April 4, 2018
Science Daily/Arizona State University
A first-of-its-kind study shows that in the college biology classroom, men perceive themselves as smarter, even when compared to women whose grades demonstrate they are just as accomplished. The study shows that gender greatly impacts students' perceptions of their own intelligence, particularly when they compare themselves to others.
If you believe it, you can achieve it.
You've probably heard this motivational phrase more than once. But what if your beliefs about your own intelligence compared to others come down to your gender?
A first-of-its-kind study shows that in the college biology classroom, men perceive themselves as smarter, even when compared to women whose grades prove they are just as smart. The study, published April 4 in the journal Advances in Physiology Education, shows that gender greatly impacts students' perceptions of their own intelligence, particularly when they compare themselves to others.
Katelyn Cooper, a doctoral student in the Arizona State University School of Life Sciences and lead author of the study, has talked with hundreds of students as an academic advisor and those conversations led to this project.
"I would ask students about how their classes were going and I noticed a trend," shared Cooper. "Over and over again, women would tell me that they were afraid that other students thought that they were 'stupid.' I never heard this from the men in those same biology classes, so I wanted to study it."
The ASU research team asked college students enrolled in a 250-person biology course about their intelligence. Specifically, the students were asked to estimate their own intelligence compared to everyone in the class and to the student they worked most closely with in class.
The researchers were surprised to find that women were far more likely to underestimate their own intelligence than men. And, when comparing a female and a male student, both with a GPA of 3.3, the male student is likely to say he is smarter than 66 percent of the class, and the female student is likely to say she is smarter than only 54 percent of the class.
In addition, when asked whether they are smarter than the person they worked most with in class, the pattern continued. Male students are 3.2 times more likely than females to say they are smarter than the person they are working with, regardless of whether their class partners are men or women.
A previous ASU study has shown that male students in undergraduate biology classes perceive men to be smarter than women about course material, but this is the first study to examine undergraduate student perceptions about their own intelligence compared to other people in the class.
Is this a problem?
"As we transition more of our courses into active learning classes where students interact more closely with each other, we need to consider that this might influence how students feel about themselves and their academic abilities," shared Sara Brownell, senior author of the study and assistant professor in the school. "When students are working together, they are going to be comparing themselves more to each other. This study shows that women are disproportionately thinking that they are not as good as other students, so this a worrisome result of increased interactions among students."
Brownell added that in a world where perceptions are important, female students may choose not to continue in science because they may not believe they are smart enough. These false perceptions of self-intelligence could be a negative factor in the retention of women in science.
Cooper said: "This is not an easy problem to fix. It's a mindset that has likely been engrained in female students since they began their academic journeys. However, we can start by structuring group work in a way that ensures everyone's voices are heard. One of our previous studies showed us that telling students it's important to hear from everyone in the group could be enough to help them take a more equitable approach to group work."
November 29, 2017
Science Daily/University of Cambridge
Making eye contact with an infant makes adults' and babies' brainwaves 'get in sync' with each other -- which is likely to support communication and learning.
When a parent and infant interact, various aspects of their behaviour can synchronise, including their gaze, emotions and heartrate, but little is known about whether their brain activity also synchronises -- and what the consequences of this might be.
Brainwaves reflect the group-level activity of millions of neurons and are involved in information transfer between brain regions. Previous studies have shown that when two adults are talking to each other, communication is more successful if their brainwaves are in synchrony.
Researchers at the Baby-LINC Lab at the University of Cambridge carried out a study to explore whether infants can synchronise their brainwaves to adults too -- and whether eye contact might influence this. Their results are published in the Proceedings of National Academy of Sciences (PNAS).
The team examined the brainwave patterns of 36 infants (17 in the first experiment and 19 in the second) using electroencephalography (EEG), which measures patterns of brain electrical activity via electrodes in a skull cap worn by the participants. They compared the infants' brain activity to that of the adult who was singing nursery rhymes to the infant.
In the first of two experiments, the infant watched a video of an adult as she sang nursery rhymes. First, the adult -- whose brainwave patterns had already been recorded -- was looking directly at the infant. Then, she turned her head to avert her gaze, while still singing nursery rhymes. Finally, she turned her head away, but her eyes looked directly back at the infant.
As anticipated, the researchers found that infants' brainwaves were more synchronised to the adults' when the adult's gaze met the infant's, as compared to when her gaze was averted Interestingly, the greatest synchronising effect occurred when the adults' head was turned away but her eyes still looked directly at the infant. The researchers say this may be because such a gaze appears highly deliberate, and so provides a stronger signal to the infant that the adult intends to communicate with her.
In the second experiment, a real adult replaced the video. She only looked either directly at the infant or averted her gaze while singing nursery rhymes. This time, however, her brainwaves could be monitored live to see whether her brainwave patterns were being influenced by the infant's as well as the other way round.
This time, both infants and adults became more synchronised to each other's brain activity when mutual eye contact was established. This occurred even though the adult could see the infant at all times, and infants were equally interested in looking at the adult even when she looked away. The researchers say that this shows that brainwave synchronisation isn't just due to seeing a face or finding something interesting, but about sharing an intention to communicate.
To measure infants' intention to communicate, the researcher measured how many 'vocalisations' infants made to the experimenter. As predicted, infants made a greater effort to communicate, making more 'vocalisations', when the adult made direct eye contact -- and individual infants who made longer vocalisations also had higher brainwave synchrony with the adult.
Dr Victoria Leong, lead author on the study said: "When the adult and infant are looking at each other, they are signalling their availability and intention to communicate with each other. We found that both adult and infant brains respond to a gaze signal by becoming more in sync with their partner. This mechanism could prepare parents and babies to communicate, by synchronising when to speak and when to listen, which would also make learning more effective."
Dr Sam Wass, last author on the study, said: "We don't know what it is, yet, that causes this synchronous brain activity. We're certainly not claiming to have discovered telepathy! In this study, we were looking at whether infants can synchronise their brains to someone else, just as adults can. And we were also trying to figure out what gives rise to the synchrony.
"Our findings suggested eye gaze and vocalisations may both, somehow, play a role. But the brain synchrony we were observing was at such high time-scales -- of three to nine oscillations per second -- that we still need to figure out how exactly eye gaze and vocalisations create it."
November 17, 2017
Science Daily/University of Illinois College of Agricultural, Consumer and Environmental Sciences
A family studies researchers believed that if the attention restoration theory, which describes how interaction with natural environments can reduce mental fatigue and restore attention, worked for individuals it might also work for families to help facilitate more positive family interactions and family cohesion. They tested their theory by looking at sets of moms and daughters who were asked to take a walk together in nature and a walk in a mall.
Spending time together with family may help strengthen the family bond, but new research from the University of Illinois shows that specifically spending time outside in nature -- even just a 20-minute walk -- together can help family members get along even better.
The research is based on the attention restoration theory which describes how interaction with natural environments can reduce mental fatigue and restore attentional functioning. Many studies have supported the theory, but most, if not all, previous studies have only looked at the benefits of spending time in nature on an individual's attention.
U of I family studies researchers Dina Izenstark and Aaron Ebata believed that if this theory worked for individuals it might also work for families and help to facilitate more positive family interactions and family cohesion. So last year they developed a new theoretical approach to studying the benefits of family-based nature activities.
"Past research shows that in nature individuals' attention is restored but we wanted to know, what does that mean for family relationships? In our theoretical model we made the case that when an individual's attention is restored, they are less irritable, have more self-control, and are able to pick up on social cues more easily. Because of all of those dynamics, we believe they should get along better with other family members," Izenstark explains.
In a new study, Izenstark, now an assistant professor at San José State University, and Ebata, an associate professor and Extension specialist in the Department of Human Development and Family Studies at U of I, test their theory by looking at sets of moms and daughters (ages 10-12 years) who were asked to take a walk together in nature and a walk in a mall. The researchers then tested both the mothers' and daughters' attention and observed their family interactions after each walk.
The results were clear; a walk in nature increased positive interactions, helping the mothers and daughters get along better. It also restored attention, a significant effect for mothers in the study.
"We know that both moms and daughters experience mental or attentional fatigue. It's common especially after a full day of concentrating at work or at school," Izenstark says. "If you think about our everyday environments, not only are you at work, but maybe your cell phone is constantly buzzing, and you're getting emails. With all the stimuli in our everyday environments, our attention is taxed more than we realize."
Izenstark adds that in order to relieve some of that mental fatigue, people need to restore their directed attention. "In nature, you can relax and restore your attention which is needed to help you concentrate better. It helps your working memory."
To test the mothers' and daughters' cohesiveness and whether attention was restored, 27 mom/daughter dyads met at a homelike research lab on campus before each walk. For 10 minutes they engaged in attention-fatiguing activities (i.e. solving math problems, word searches) while a recording of loud construction music played in the background. The researchers gave them a "pre-attention" test, and then set them out on a walk -- one day to a nature arboretum, and then on another day to a local indoor mall. Each walk was 20 minutes long.
After returning from each walk, the moms and daughters were interviewed separately. They were given a "post-attention" test, and were surveyed about which location they found the most fun, boring, or interesting. They were then videotaped playing a game that required them to work together.
For moms, attention was restored significantly after the nature walk. Interestingly, for daughters, attention was restored after both walks, which Izenstark says may be a result of spending family leisure time with their mother.
"It was unique that for the daughters walking with moms improved their attention. But for the moms, they benefitted from being in a nature setting. It was interesting to find that difference between the family members. But when we looked at their subjective reports of what they felt about the two settings, there was no question, moms and daughters both said the nature setting was more fun, relaxing, and interesting."
The last aspect of the findings was in regards to improved cohesion or togetherness in the mom/daughter pairs. After analyzing the videotaped interactions during the game, the researchers only found an effect for nature; after the nature walk, moms and daughters displayed greater dyadic cohesion, a sense of unity, closeness, and the ability to get along, compared to the indoor walk.
Although the study only focused on mothers and daughters, Izenstark says that the overall aim of the research is to examine different ways in which nature affects family relationships in general.
"First and foremost I hope it encourages families to find ways to get outside together, and to not feel intimidated, thinking, 'oh, I have to go outside for an hour or make it a big trip.' Just a 20-minute walk around the neighborhood before or after eating dinner or finding pockets of time to set aside, to reconnect, not only can benefit families in the moment but a little bit after the activity as well."
New research evaluates gender differences in cooperation
April 16, 2018
Science Daily/Chapman University
Researchers have measured gender differences in cooperation and punishment behavior. Results showed that men punish more than women, men obtain higher rank, and punishment by males decreases payoffs for both sexes. Furthermore, men are willing to punish people who have done nothing wrong, except cooperate to the fullest extent possible.
Results suggest that status-seeking men are willing to impose enormous costs on others and destroy their group to move up in the hierarchy. According to the study, men may punish more than women for two reasons: First, punishment is often viewed as similar to physical conflict. Men are known to favor physical punishment of unfair behavior. Men are also less cooperative and less generous compared with their female counterparts.
Second, status affects cooperative behavior and women may feel differently about status and rank. If so, punishment may be a tool used by certain individuals to advance in rank. For example, explicit rank-based incentives caused men to punish at roughly twice the rate of women.
"Outside the laboratory, high-powered punishment and rank-based reward may be the norm," said Terence Burnham, Ph.D, associate professor in Chapman University's Argyros School of Business and Economics, and sole author of this study. "This study connects academic research to current headlines including the #metoo movement."
Mixed-gender situations with the ability to punish others occur daily in the workplace. These types of punishments can range from reputational harm to more direct financial impacts such as being terminated from your position. Studies of gender and costly cooperation are relatively rare, and existing studies reveal no clear relationship between gender and certain cooperative behaviors.
Dr. Burnham conducted a public goods game with 96 undergraduate students from Chapman University. Four experimental sessions with 24 subjects each had equal numbers of men and women. During this game, subjects secretly chose how many of their private tokens to place into a public pot, with each participant keeping the tokens they did not contribute. The tokens in this pot were multiplied by 1.6 and divided equally among four players in a group. All decisions were made via independent computers, while subjects were instructed not to look at anyone's screen or speak to one another. Participants in each session played this game with and without rank-based payoffs.
March 1, 2018
Science Daily/University of Arizona
Women report more incivility at work than men, and according to new research, it's other women who are responsible for it.
The phenomenon of women discriminating against other women in the workplace -- particularly as they rise in seniority -- has long been documented as the "queen bee syndrome." As women have increased their ranks in the workplace, most will admit to experiencing rude behavior and incivility.
Who is at fault for dishing out these mildly deviant behaviors? Has the syndrome grown more pervasive?
"Studies show women report more incivility experiences overall than men, but we wanted to find out who was targeting women with rude remarks," said Allison Gabriel, assistant professor of management and organizations in the University of Arizona's Eller College of Management.
Gabriel and her co-authors set out to answer that question across three studies. Men and women who were employed full time answered questions about the incivility they experienced at work during the last month. The questions were about co-workers who put them down or were condescending, made demeaning or derogatory remarks, ignored them in a meeting or addressed them in unprofessional terms. Each set of questions was answered twice, once for male co-workers and once for female co-workers.
"Across the three studies, we found consistent evidence that women reported higher levels of incivility from other women than their male counterparts," Gabriel said. "In other words, women are ruder to each other than they are to men, or than men are to women.
"This isn't to say men were off the hook or they weren't engaging in these behaviors," she noted. "But when we compared the average levels of incivility reported, female-instigated incivility was reported more often than male-instigated incivility by women in our three studies."
Participants also were asked to complete trait inventories of their personalities and behaviors to determine if there were any factors that contributed to women being treated uncivilly. The research showed that women who defied gender norms by being more assertive and dominant at work were more likely to be targeted by their female counterparts, compared to women who exhibited fewer of those traits.
The researchers also found that when men acted assertive and warm -- in general, not considered the norm for male behavior -- they reported lower incivility from their male counterparts. This suggests men actually get a social credit for partially deviating from their gender stereotypes, a benefit that women are not afforded.
Gabriel, whose co-authors are Marcus Butts from Southern Methodist University, Zhenyu Yuan of the University of Iowa, Rebecca Rosen of Indiana University and Michael Sliter of First Person Consulting, said the research is important not only from the standpoint of individual employee health but also in terms of organizational management.
Evidence emerged in the three studies that companies may face a greater risk of losing female employees who experience female-instigated incivility, as they reported less satisfaction at work and increased intentions to quit their current jobs in response to these unpleasant experiences. Paired with estimates that incivility can cost organizations an estimated $14,000 per employee, this presents a problem for organizations.
Gabriel noted that the findings are an opportunity for companies to re-evaluate their cultures and how they address this issue.
"Companies should be asking, 'What kinds of interventions can be put in place to really shift the narrative and reframe it?'" Gabriel said. "Making workplace interactions more positive and supportive for employees can go a long way toward creating a more positive, healthier environment that helps sustain the company in the long run. Organizations should make sure they also send signals that the ideas and opinions of all employees are valued, and that supporting others is crucial for business success -- that is, acting assertively should not be viewed negatively, but as a positive way for employees to voice concerns and speak up."
December 5, 2017
Science Daily/University of Texas at Arlington
Researchers have revisited workplace sexual harassment issues after the initial study was done nearly 20 years ago
How well is society doing?
The answer is mixed. Although there has been a 28 percent decline in complaints, sexual harassment is a continuing, chronic occupational health problem in the workplace.
James Campbell Quick, the John and Judy Goolsby-Jacqualyn A. Fouse Endowed Chair in UTA's Goolsby Leadership Academy, initially published the report in a 1998 special section on sexual harassment in the Journal of Occupational Health Psychology.
Quick and M. Ann McFadyen, a UTA associate professor of strategic management, conducted the review earlier this year. It comes at a time when noteworthy sexual harassment and assault incidents have permeated all aspects of American society.
"Our current examination of the evidence suggests that sexual harassment is a continuing occupational problem," Quick said. "Have we made progress? Yes, there has been progress on some fronts but not on others and the problem has morphed, becoming more complicated for a variety of reasons found in the current data."
Society and the workplace continue to struggle with the very definition of sexual harassment, which limits the ability to develop effective strategies in the workplace.
Plus, McFadyen said that the workforce is changing.
"Sexual harassment in the workplace is costly, not just to the organization," McFadyen said. "The behavior impacts the victim, the aggressor, bystanders, customers, suppliers and other stakeholders in terms of tarnished reputations and trust, disengaged employees, decreased commitment, turnover, depression, stress, eating and other health disorders and in extreme cases bodily harm, even death."
She said that the recent publicity regarding sexual harassment is a signal of the beginning of a revolutionary change in the workplace demanding a different type of training.
"Training not only for leaders and management but employees at all ranks, customers, suppliers and other stakeholders," McFadyen said. "Successful leaders and management of organizations cannot afford to simply maintain the status quo."
Both believe that there is a real need from a public heath perspective to know more about the aggressors' use of power in sexual harassment cases.
The two professors believe that if the workplace is equipped with this information, surveillance indicators and systems can be put into place to address this preventable occupational health problem.
Antonio Puente, the American Psychological Association president, used the Quick-McFadyen report in a letter to members last month.
"Sexual harassment in the workplace is a significant occupational health psychology problem," Puente said. "Psychological research has offered understanding into the causes of workplace harassment, as well as some strategies for preventing or reducing it. However, there is limited research regarding the characteristics of harassers, which makes it difficult to predict who will do it and where and when it might happen. What we do know is that harassers tend to lack a social conscience and engage in manipulative, immature, irresponsible and exploitative behaviors."
He said organizations need to be proactive in establishing policies prohibiting sexual harassment, raising employee awareness, establishing reporting procedures and educating employees about these policies.
"More research is needed to identify the antecedents to harassment that will help employees and managers identify and respond appropriately," Puentes said.
June 12, 2018
Science Daily/Fred Hutchinson Cancer Research Center
A breast cancer patient dealing with anxiety, depression or mood swings could soon be encouraged by her oncologist to learn meditation techniques, join a yoga class or put music to therapeutic use.
The SIO guidelines were reviewed by an ASCO expert panel co-chaired by Dr. Gary H. Lyman, an oncologist with Fred Hutchinson Cancer Research Center in Seattle, and Dr. Lorenzo Cohen of the University of Texas MD Anderson Cancer Center in Houston.
The full guidelines appear online in the Journal of Clinical Oncology. Some of the key recommendations include:
· Music therapy, meditation, stress management, and yoga are recommended for anxiety/stress reduction.
· Meditation, relaxation, yoga, massage, and music therapy are recommended for depression/mood disorders.
· Meditation and yoga are recommended to improve quality of life.
· Acupressure and acupuncture in addition to anti-nausea medications are recommended for reducing chemotherapy-induced nausea and vomiting.
· Glutamine is not recommended for improving nausea and vomiting during chemotherapy.
· Acetyl-L-carnitine is not recommended to prevent chemotherapy-induced peripheral neuropathy because of a possibility of harm.
· No strong evidence supports the use of ingested dietary supplements to manage breast cancer treatment-related adverse effects.
"Patients undergoing and surviving breast cancer treatment naturally want to use every tool available to them to enhance the effectiveness of treatment and improve their quality of life," Lyman said. "Our goal is to help cancer care specialists and their patients make appropriate individualized treatment decisions -- evaluating the current medical literature on complementary therapies to determine what works, what doesn't work and what might actually be harmful instead of helpful. The guidelines should be seen only as that -- guidelines -- because each patient's case is unique, and there's nothing more important than the judgment of an independent, caring professional. There is a considerable lack of information on the benefits and harms of many integrative therapies in oncology and further rigorous research of such methods is greatly needed."
ASCO's expert panel said recommendations may be subject to change as additional scientific evidence is compiled, and although ASCO generally endorsed the SIO recommendations, the panel brought attention to several areas of discussion, including safety concerns about mistletoe, sometimes taken to improve quality of life, and ginseng, sometimes taken to counter fatigue. Certain forms of ginseng could have estrogenic properties, but more research is needed to evaluate risk in patients with estrogen receptor-positive breast cancer.
June 12, 2018
Science Daily/University of Cambridge
Mothers who 'connect' with their baby during pregnancy are more likely to interact in a more positive way with their infant after it is born, according to a new study. Interaction is important for helping infants learn and develop.
Researchers at the Centre for Family Research carried out a meta-analysis, reviewing all published studies in the field, in an attempt to demonstrate conclusively whether there was a link with the way parents think about their child during pregnancy and their behaviour towards them postnatally.
The results of their work, which draws data from 14 studies involving 1,862 mothers and fathers, are published in the journal Developmental Review.
Studies included in the meta-analysis examined parents' thoughts and feelings about their child during pregnancy through interviews and questionnaires. For example, in interviews expectant parents were considered to have a 'balanced' representation of their child if they showed positive anticipation of their relationship with the child or showed 'mind-mindedness' -- a propensity to see their child as an individual, with its own thoughts and feelings. This was contrasted by parents who had a 'distorted' representation of their child, with a narrow, idealised description of their child, and incomplete or inconsistent descriptions of them.
Once the child had been born, researchers in these studies would observe the interactions between parent and child. One measure they were looking for was 'sensitivity' -- the ability to notice, interpret and respond in a timely and appropriate manner to children's signals, for example if the baby was upset.
Combining the results from all 14 studies, the Cambridge team showed a modest association between positive thoughts and feelings about the infant during pregnancy and later interaction with the infant, but only in mothers.
"Studies have shown that parent-child interaction is crucial for a child's development and learning, so we wanted to understand if there were prenatal signs that might predict a parent's behaviour," says Dr Sarah Foley, the study's first author, who carried out the research as part of her PhD.
"Although we found a relationship between a mother's attitude towards her baby during pregnancy and her later interactions, this link was only modest. This suggests it is likely to be a part of the jigsaw, rather than the whole story."
Research has also shown that increased awareness of the baby during pregnancy is associated with healthy behaviours during pregnancy, such as giving up smoking or attending antenatal appointments.
While more work is needed to determine what form such interventions might take, options might include the midwife encouraging the mother to think about what her baby may be like, or asking the mother to imagine activities they think she and her baby might like to do together.
"This is a relatively new area of research, but could have important implications for children's development," adds Dr Foley. "We need more research in this area, but hope it will inform new interventions that could help new mothers engage more with their children."
Dr Foley says there may be a number of factors that contribute to low levels of attachment with the baby during pregnancy. These include: previous experience of miscarriage, depression or anxiety, a mother's relationship with her own parents, or cultures in which focusing on the baby is considered inappropriate. However, she says, the paucity of evidence means it is difficult to determine which of these factors would impact on prenatal thoughts about the infant, which might in turn influence the quality of later interaction with the infant.
The study was funded by the Economic and Social Research Council.
Researcher Profile: Dr Sarah Foley
"Working with children throws up lots of unexpected and fun moments," says Dr Sarah Foley. "One day you're being splashed whilst standing on a toilet-seat filming bath-times, the next you're catching YouTube-worthy vomiting action shots and being used as a climbing frame by one child to ensure you can film another!"
Sarah has just completed an ESRC-funded PhD at the Centre for Family Research, working with Professor Claire Hughes. She has spent several years at Cambridge now, having completed her undergraduate degree in Social and Political Sciences at St Catharine's College. The Centre, she says, "is an incredibly stimulating academic environment with immense support and lively discussions over cake on a Friday morning!"
Her doctoral research looked at expectant mothers' and fathers' thoughts and feelings in the last trimester of pregnancy as predictors of their adjustment to parenthood and subsequent parenting over the first two years of life. "Despite an increase in fathers' involvement in childcare, the majority of research remains focused on mothers," she says.
Her current research involves, in part, looking at parents' expectations of their roles and division of childcare, and the consequences when these expectations are not met. This is timely in light of recent changes to parental leave in the UK and societal shifts in notions of the involved father, she says.
Sarah's research is part of the ERSC-funded New Fathers and Mothers Study, a longitudinal study of 200 first time parents from Cambridge, and 200 from the Netherlands and New York.
"The children in the study are turning three this year and we're busy seeing how they are getting on at nursery," she explains. "This typically involves me getting down on the floor and testing the children's social understanding and thinking skills through a variety of fun tasks."
She hopes that her research will lead to changes in antenatal education and early parent support that promote discussion of parents' thoughts and feelings about parenthood and their future infant. In November 2017, as part of the ESRC Festival of Social Science, she ran a free ante-natal class for new parents that discussed the realities of parenthood, the importance of self-care and simple parenting tips rather than simply focusing on birth plans.
"The journey through parenthood is filled with joy, but also elements of confusion, and sometimes pain. Crucially, parents should not feel alone and I hope that through greater dissemination of my research findings, through classes or perhaps a book or an app, we can support new parents and encourage more 'honest conversations' about parenthood."
Study shows importance of maternal 'gatekeeping'
June 11, 2018
Science Daily/Ohio State University
How a new mother reacts to her partner's early interactions with their baby may affect his parenting quality later on, a new study suggests. Researchers found that fathers did not perform as well as a parent to their 9-month-old child if the dads felt their partner was critical of their parenting skills six months earlier.
Researchers found that fathers did not perform as well as a parent to their 9-month-old child if the dads felt their partner was critical of their parenting skills six months earlier.
The study -- done with relatively affluent, highly educated dual-earner couples -- is the first to show how fathers' parenting quality might be affected by "maternal gatekeeping."
That's the term researchers use to describe the behaviors and attitudes of mothers that may support or limit father involvement in child rearing.
"The behaviors of mothers can shape how fathers interact with their children," said Lauren Altenburger, lead author of the study, who did the work as a doctoral student in human sciences at The Ohio State University.
"Mothers may not even be aware of how their criticisms of the father may end up negatively influencing how dads parent."
The study appears online in the Journal of Child and Family Studies.
The results reflect the fact that, in our society, mothers still have the most power and influence when it comes to raising children, said study co-author Sarah Schoppe-Sullivan, professor of human sciences at Ohio State.
"Many fathers may be more vulnerable to criticism than mothers are because there is still less support in our society for fathers as active, involved parents," she said.
The researchers used data from the New Parents Project, a long-term study co-led by Schoppe-Sullivan that is investigating how dual-earner couples adjust to becoming parents for the first time. In all, 182 couples, most of whom were married, participated in this study.
The parents were assessed twice: when their child was 3 months old and when he or she was 9 months old.
Fathers answered questions at both time points to gauge how much they felt their partner "opened" or "closed" the gate to their involvement in child care.
For example, each dad reported how often his partner took over baby-related tasks because the mom thought he wasn't doing them properly and how often she gave him irritated looks about his parenting, which are gate closing. Examples of gate opening include encouraging the father to help bathe the baby or mom letting him know she appreciates his contributions to parenting.
The researchers measured parenting quality by observing the father interacting with his child for three minutes when the infant was 3 months old and five minutes when he or she was 9 months old.
The fathers were rated on a variety of factors, such as how appropriately they responded to the child's gestures and expressions, how engaged they were with the child and how much they smiled and spoke in a warm tone.
Findings showed that the more the fathers reported gate closing by their partner when the child was 3 months old, the worse researchers rated their parenting quality at 9 months old.
"If fathers feel their partners don't have confidence in their parenting, they may withdraw, and become less positive and sensitive with their child," Altenburger said.
One theory is that mothers may close the gate on fathers because dads show evidence of poor parenting. But in this study, poorer parenting at 3 months was not linked to maternal gate closing at 9 months, which would be expected if this theory were correct.
Schoppe-Sullivan noted that this sample of dual-earner couples may be different from other families. "We might see more evidence of protective gatekeeping by mothers in more distressed families," she said.
The researchers said that both mothers and fathers need to be supportive to each other in those early months after their first baby is born.
The transition to parenthood is challenging and both parents often feel vulnerable, Schoppe-Sullivan said, because they are still developing their identities as parents.
But fathers may be especially vulnerable to criticism.
"There still is an assumption in our society that mothers are the primary caregivers and that they have the power to determine the involvement of others in child care," she said. "Fathers may feel they should withdraw if they don't have their partner's support."
The results suggest moms should think twice before criticizing dads' parenting choices on minor issues such as what their baby will wear on a particular day, Altenburger said.
"It is about giving fathers the space to parent, too. Both parents need to keep communication open and not be so quick to criticize," she said.
Study finds increased happiness during pregnancy decreases sleep disturbances for kids
June 5, 2018
Science Daily/American Academy of Sleep Medicine
Maternal depressive mood during the prenatal and postnatal periods is related to child sleep disturbances, according to recent pilot data from a longitudinal cohort study in kindergarten children.
"The most surprising thing about our results was the mediation role of child behavior in the maternal emotion-children's sleep quality relationship, this demonstrates that emotion during pregnancy affects child behavior which further affects child's sleep, said principal investigator and lead author Jianghong Liu, PhD, RN, FAAN, an associate professor at the Schools of Nursing and Medicine at the University of Pennsylvania. "Furthermore, we found that happiness increased across the trimesters and that happiness during the second and third trimester was protective against child sleep problems."
Participants included 833 kindergarteners with mean age of about six years old. Women's emotional status, including prenatal/postnatal depressive emotion and perceived happiness throughout trimesters, was rated by a self-designed set of questions with a 5-point scale for happiness and a 3-point scale for depression. Sleep problems were assessed using the sleep subdomain of the Child Behavior Checklist (CBCL). Child behavioral problems were measured using the CBCL total score. General linear models were performed to examine the adjusted associations between childhood sleep problems and maternal emotional status.
Adjusted models showed that children of women who expressed either depressive emotion during the postnatal period (?=3.13, p=0.003) or during both the prenatal and postnatal periods (?=2.65, p=0.04) were more likely to exhibit sleep disturbances. Similarly, increased levels of happiness in the second and third trimester were significantly associated with decreased risk for children's sleep problems. Results show a significant mediation effect of child's behavior on the maternal emotion and child sleep relationship.
According to Liu and her co-authors (Xiaopeng Ji, Guanghai Wang, Yuli Li and Jennifer Pinto-Martin), these results are noteworthy because they highlight the importance of prenatal maternal emotional health and its impact on child sleep outcomes.
"These results promote the caretaking of maternal health and happiness during pregnancy and encourage the roles of familial and community support in aiding expecting mothers. This will benefit not only maternal health but also the long term behavioral and sleep health of their child," said Liu.
May 21, 2018
Science Daily/University of Illinois College of Agricultural, Consumer and Environmental Sciences
A new study looks at the link between maternal sleep and permissive parenting during late adolescence. Findings show that mothers who don't get enough sleep or who take longer falling asleep have a greater tendency to engage in permissive parenting -- parenting marked by lax or inconsistent discipline.
A new study from Kelly Tu, a human development and family studies researcher at the University of Illinois, and colleagues, looks at the link between maternal sleep and permissive parenting during late adolescence. Findings show that mothers who don't get enough sleep or who take longer falling asleep have a greater tendency to engage in permissive parenting -- parenting marked by lax or inconsistent discipline.
Results also show that sleep quality may be especially important for African-American mothers and mothers from socioeconomically disadvantaged households.
"Short and disrupted sleep patterns are common among parents, especially parents of young children, and can affect their mental and physical health and daily functioning," explains Tu, assistant professor in the Department of Human Development and Family Studies at U of I. "Extending this work beyond young children, we were curious as to how sleep affects the parenting of adolescents."
During adolescence -- 11 to 18 years of age -- parental involvement is still an important contributing factor in how well kids are adjusting socially, emotionally, and behaviorally. Tu explains that research has shown a link between permissive parenting and adolescents' vulnerability to problematic or risky behaviors.
Those risky behaviors during adolescence could include affiliating with deviant or delinquent peers, engaging in delinquent behavior (vandalism or skipping school), or substance use and abuse, Tu explains. "Given that permissive parenting may heighten the risk of adolescents' risky behaviors, we wanted to take a step back to ask what's driving these permissive parenting behaviors, and to see if sleep could be a contributing factor.
"We found that when mothers were not receiving enough sleep, or receiving poor quality sleep, it had an effect on their levels of permissiveness with their adolescents. It may be that they're more irritable, experiencing impaired attention, or so over-tired that they are less consistent in their parenting. But on the plus side, we also find that mothers who are receiving adequate sleep are less likely to be permissive with their adolescents."
To examine maternal sleep duration and quality, 234 mothers were asked to wear actigraphs -- a wristwatch-like device, think of a Fitbit -- at bedtime for seven consecutive nights. The actigraph detects movement throughout the night and determines whether there is a disruption in sleep. Information about race/ethnicity and socioeconomic status of the mothers was also collected.
Adolescents, averaging 15 years of age, then completed questionnaires (subscales of the Parent Behavior Inventory) about how they perceived their mothers' parenting. They rated behavior on a scale of "likely or not likely to." Example statements included, "Lets me off easy when I do something wrong," "Can't say no to anything I want," or "Doesn't check up to see whether I have done what she told me."
Findings showed that mothers who had longer durations of sleep or who were able to fall asleep easily, had adolescents who reported lower levels of permissive parenting.
Race/ethnicity and socioeconomic status also emerged as significant factors in linking sleep quality with permissive parenting. African-American mothers and mothers from lower socioeconomic households who experienced higher quality sleep (higher sleep efficiency, fewer night wakings) had lower levels of permissive parenting. Yet, for these same mothers, poorer sleep quality resulted in higher levels of permissive parenting.
"Studies have documented sleep disparities among ethnic minority and socioeconomically disadvantaged individuals, and our findings are consistent with that. For socioeconomic status, we may need to consider the day-to-day stressors or challenges that these mothers are facing," Tu explains. "Mothers from lower socioeconomic households may be encountering additional stressors or financial hardships that could be affecting their sleep and/or parenting. "But what's exciting is that we also find positive effects of high quality sleep on parenting behaviors for ethnic minority and socioeconomically disadvantaged mothers," Tu says.
The findings from the study, Tu says, point out the need for self-care and the importance of sleep.
"Sleep is an easier point to intervene in terms of changes individuals can make -- things like not drinking caffeine or exercising too close to bedtime, establishing a bedtime routine, and thinking about the sleep environment," she says. "Parents may be thinking about these things when it comes to their children, but it's just as important for parents to get enough sleep as it may impact their family interactions and children's well-being."
April 24, 2018
Science Daily/University of Michigan
While some research suggests that midlife is a dissatisfying time for women, other studies show that women report feeling less stressed and enjoy a higher quality of life during this period.
So, which is it? A recent University of Michigan study by Elizabeth Hedgeman, a doctoral graduate of the U-M School of Public Health, and colleagues found that perceived stress -- a measure of confidence, control and ability to cope with life's stressors -- did indeed decrease for most women over a 15-year span.
The study also found that menopausal status wasn't a factor, which challenges the notion that menopause is associated with higher stress and depression.
The results come from data collected from more than 3,000 women who were recruited between the ages of 42-53 for the Study of Women's Health Across the Nation.
Hedgeman's goal was to assess the effects of age, menopausal status and sociodemographics on stress over time. She did the work while in the lab of Sioban Harlow, professor of epidemiology at the U-M School of Public Health.
By the end of the study period, the mean age was 62 and stress declined with age across nearly all sociodemographic categories. Compared to similar black, white and Chinese women, stress decreased in a more attenuated fashion for Japanese women. After adjusting for other sociodemographic variables, race and ethnicity was a significant predictor of increased stress only for Japanese women.
Women with less education and increased financial hardship consistently reported higher levels of stress compared to their peers, but this difference diminished over time.
"The results suggested that even women with less education or more financial hardship reported less perceived stress over the midlife," Hedgeman said. "And then there's menopause.
"Our perception of stress decreased even through the menopausal transition, which suggests that menopause isn't a great bugaboo, perhaps in relation to the other events or experiences that we're having in the midlife."
Education, employment and financial hardship were stronger predictors of perceived stress over midlife than the menopause transition, and this may suggest that women experience the menopausal transition as a series of acute stressors (hot flashes, sleep disturbances) that can be muted by chronic, socioeconomic-based life stressors.
The only groups that reported increased perceived stress over the study were Hispanic and white women from New Jersey, but Hedgeman said these are outlier results that needed to be replicated. Additionally, there were extenuating circumstances at the New Jersey site that may have contributed.
Despite reporting decreased levels of stress throughout life, women who reported higher stress at the start of midlife continued to report higher stress levels than their peers as they aged. This is important because stress is a known health risk.
The study did not specifically examine the reasons for this decrease in perceived stress, but Hedgeman said that there could be both circumstantial and neurological causes -- children have moved out, professional goals are being met, or women might have hit a sweet spot before the next life challenges arise, such as chronic health conditions or aging parents.
Existing research also suggests that aging helps us regulate our emotions. "Perhaps things just don't bother us as much as we age, whether due to emotional experience or neurochemical changes. It's all worth exploring," Hedgeman said. Overall, the findings are good news for women transitioning through midlife, she said.
"The neat thing is that for most of us, our perception of stress decreases as we age through the midlife -- perhaps life itself is becoming less stressful, or maybe we're finally feeling at the top of our game, or maybe things just don't bother us the way they did," Hedgeman said. "But whatever the root reason, we're reporting less perceived stress as we age through the midlife and menopause."
The primary limitation of the study was the inability to understand perceived stress among women reporting the highest levels over time. Also, a disruption of operations at the New Jersey site, limited the number of visits to five, not 13 as with the other sites. Also, New Jersey was the only site that recruited Hispanic women.
Co-authors include: Rebecca Hasson, assistant professor of kinesiology and nutritional sciences; Carrie Karvonen-Gutierrez, assistant professor of epidemiology; and William Herman, professor of internal medicine and epidemiology.
April 19, 2018
A new study has determined that poorer childhood cognition occurred, particularly in memory and learning, when pregnant women or their offspring consumed greater quantities of sugar. Substituting diet soda for sugar-sweetened versions during pregnancy also appeared to have negative effects. However, children's fruit consumption had beneficial effects and was associated with higher cognitive scores.
Research is increasingly focusing on the adverse impact of sugar consumption on health, especially high-fructose corn syrup. Sugar consumption among Americans is above recommended limits, and the Current Dietary Guidelines for Americans emphasize the importance of reducing calories from added sugars. They are incorporated into foods and beverages during preparation or processing, with sugar-sweetened beverages (SSBs) being the greatest contributor in Americans' diets. Evidence is also emerging that sugar consumption may negatively impact children's cognitive development.
"The aim of our study was to examine associations of pregnancy and offspring sugar consumption (sucrose, fructose) with child cognition," explained lead investigator Juliana F.W. Cohen, ScD, School of Health Sciences, Merrimack College, North Andover, MA, and Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA. "Additionally, we examined associations of maternal and child consumption of SSBs, other beverages including diet soda and juice, and fruit with child cognition."
Investigators collected dietary assessment data for more than 1,000 pregnant women from 1999 to 2002 who participated in Project Viva. Their offspring's diets were assessed in early childhood. Child cognition was assessed in early- and mid-childhood (at approximately age 3 and 7, respectively).
The results of this study indicate that consuming more fruits and less sugar, as well as avoiding diet soda during pregnancy, may have a meaningful impact on child cognitive functioning. Key findings include:
· Maternal sugar consumption, especially from SSBs, was associated with poorer childhood cognition including non-verbal abilities to solve novel problems and poorer verbal memory.
· Maternal SSB consumption was associated with poorer global intelligence associated with both verbal knowledge and non-verbal skills.
· Maternal diet soda consumption was associated with poorer fine motor, visual spatial, and visual motor abilities in early childhood and poorer verbal abilities in mid-childhood.
· Childhood SSB consumption was associated with poorer verbal intelligence at mid-childhood.
· Child consumption of both fructose and fruit in early childhood was associated with higher cognitive scores in several areas and greater receptive vocabulary.
· Fruit was additionally associated with greater visual motor abilities in early childhood and verbal intelligence in mid-childhood.
· Fruit juice intake was not associated improved cognition, which may suggest the benefits are from other aspects of fruits, such as phytochemicals, and not fructose itself.
"This study provides evidence that there should be no further delays in implementing the new Nutrition Facts label. The new label will provide information on added sugars so that pregnant women and parents can make informed choices regarding added sugars and more easily limit their intake. This study also provides additional support for keeping federal nutrition programs strong, such as Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and the National School Lunch Program, because their promotion of diets higher in fruits and lower in added sugars may be associated with improved childhood cognition," commented Dr. Cohen.
Study finds maternal depression negatively impacts a child's cognitive development, infancy through age 16
April 17, 2018
Science Daily/University of California - San Diego
Roughly one in 10 women in the United States will experience depression. The consequences, however, may extend to their children, report researchers who found that a mother's depression can negatively affect a child's cognitive development up to the age of 16.
Researchers surveyed approximately 900 healthy children and their mothers living in Santiago, Chile at five-year intervals from the child's infancy through age 16. They observed how affectionate and responsive mothers were to their children at each age period, as well as how much mothers provided age-appropriate learning materials. Children were assessed on verbal cognitive abilities using standardized IQ tests during each assessment. Mothers were tested for symptoms of depression.
"We found that mothers who were highly depressed didn't invest emotionally or in providing learning materials to support their child, such as toys and books, as much as mothers who were not depressed. This, in turn, impacted the child's IQ at ages 1, 5, 10 and 16," said Patricia East, PhD, research scientist with the Department of Pediatrics at UC San Diego School of Medicine. "The consistency and longevity of these results speak to the enduring effect that depression has on a mother's parenting and her child's development."
On a scale from one to 19, the average verbal IQ score for all children in the study at age 5 was 7.64. Children who had severely depressed mothers were found to have an average verbal IQ score of 7.30 compared to a score of 7.78 in children without depressed mothers.
"Although seemingly small, differences in IQ from 7.78 to 7.30 are highly meaningful in terms of children's verbal skills and vocabulary," said East. "Our study results show the long term consequences that a child can experience due to chronic maternal depression."
Throughout the study period, at least half of the mothers were determined to be depressed based on a questionnaire with questions like, "Are you sad?" and "Do you find yourself crying?"
"For mothers in the study, there were many stressors in their lives. Most of the mothers, while literate, had only nine years of education, were not employed outside the home and often lived with extended family in small, crowded homes -- factors that likely contributed to their depression," said East. "Many mothers suffer from depression in the first six months after childbirth, but for some, depression lingers."
East said study data suggested approximately 20 percent of mothers who are severely depressed when their child turns age 1 remain depressed for a long time.
"For health care providers, the results show that early identification, intervention and treatment of maternal depression are key," said East. "Providing resources to depressed moms will help them manage their symptoms in a productive way and ensure their children reach their full potential."
Study authors said future steps include further analyzing the data to see how mothers' depression affects children's own depressive symptoms through childhood and adolescence and children's academic achievement and health, such as their likelihood of being overweight or obese.
April 11, 2018
Science Daily/American Academy of Neurology
Entering menopause at a later age may be associated with a small benefit to your memory years later, according to a new study.
"This study suggests that lifelong hormonal processes, not just short-term fluctuations during menopause, may be associated with memory skills," said study author Diana Kuh, PhD, FFPH, FMedSci, of the University College London in the United Kingdom.
The study involved 1,315 women from the Medical Research Council National Survey of Health and Development in Great Britain who had been followed since birth in March 1946. All of the women had tests of their verbal memory skills and their cognitive processing speed at ages 43, 53, between 60 and 64, and at age 69. The researchers collected information on age at menopause, either natural or due to removal of the ovaries, whether they took hormone replacement therapy, and other factors that could affect thinking and memory skills, such as childhood cognitive ability, amount of education, smoking and type of occupation.
Menopause, which is defined as the age at last menstrual cycle, started on average for the women with natural menopause at age 51 and a half.
For the verbal memory test, participants were asked to recall a 15-item list three times, with a maximum score of 45. At age 43, participants recalled an average of 25.8 words. By age 69, they recalled an average of 23.3 words. The study found that among 846 women who experienced menopause naturally, women who had later menopause had higher verbal memory scores, remembering 0.17 additional words per year. After researchers adjusted for other factors that could affect memory, the difference was 0.09 additional words per year.
"The difference in verbal memory scores for a 10-year difference in the start of menopause was small -- recalling only one additional word, but it's possible that this benefit could translate to a reduced risk of dementia years later," Kuh said. "More research and follow-up are needed to determine whether that is the case."
Kuh noted that the relationship between the age at menopause and memory scores was not affected by use of hormone therapy.
For 313 women who experienced menopause due to surgery, the relationship between age at the time of surgery and memory scores was no longer present after researchers adjusted for other factors that could affect memory.
On the test of how fast the women could process information, there was no relationship between the age at menopause and test scores.
"This difference may be due to the estrogen receptor role, which regulates the gene that codes brain-derived neurotrophic factor, which helps to solidify memory formation and storage," Kuh said.
Limitations of the study were that the tests of memory and processing speed were taken relatively far apart in time and that information was not available on the dose for women taking hormone therapy.
New study evaluates effect of menopause and depression on vascular function
April 11, 2018
Science Daily/The North American Menopause Society (NAMS)
Heart disease remains the leading cause of death in women. A study of 138 menopausal women examined the association of mood, symptoms, and quality of life measures with the key markers of vascular aging, a major risk factor for the development of cardiovascular disease (CVD).
It's no secret that the menopause transition is marked with a number of adverse health effects, including hot flashes and depression to vascular aging, which is typically seen as artery stiffening and endothelial dysfunction. With these problems all occurring around the same time in a woman's life, the authors of this latest study sought to determine whether menopause symptoms and depression are related to CVD.
The results, as reported in the article "Vascular dysfunction across the stages of the menopausal transition is associated with menopausal symptoms and quality of life," confirmed that. Across the stages of menopause, arterial stiffening and vascular dysfunction were associated with more frequent and severe menopause symptoms and a lower quality of life. No association, however, was found with depressive symptoms.
Previous studies have shown an especially strong link between hot flashes and increased cardiovascular risk and mortality. In this study, the frequency, but not severity, of hot flashes was specifically associated with greater arterial stiffening and reduced endothelial function.
"Perimenopausal and early menopausal women are more vulnerable to increased risk of cardiovascular disease," says Dr. JoAnn Pinkerton, NAMS executive director. "With fluctuating and then declining estrogen during the menopause transition, it is important to monitor mood, blood pressure, lipids, blood sugars, and body composition because of the increased risk of abdominal fat. Healthy eating and exercise are encouraged, with individualized discussion about benefits and risks of hormone therapy."
April 10, 2018
Science Daily/Dartmouth College
Vertebrate species, including humans, exposed to stress prenatally tend to have higher stress hormones after birth, according to a new study. While previous research has reported examples of maternal stress experience predicting offspring stress hormones in different species, this study is the first to empirically demonstrate the impact of prenatal stress on offspring stress hormone levels using data from all known studies across vertebrates.
Through a meta-analysis of 114 results from a total of 39 observational and experimental studies across 14 vertebrate species, including birds, snakes, sheep and humans, the study examines the impact of prenatal exposure to maternal stress on offspring. The researchers analyzed the role of the hypothalamic pituitary adrenal (HPA)-axis, the stress physiological system that is shared across all vertebrates, which ultimately, results in the production of stress hormones known as "glucocorticoids." The HPA-axis is the hormonal system responsible for mobilizing an animal's stress response. Offspring exposed prenatally to maternal stress were found to have more stress hormone levels (glucocorticoids) after birth. This could reflect a biological adaptation with an evolutionary history, as more stress hormones could increase an animal's chances for survival in a stressful environment.
In the present study, the researchers tested the strength of the effect of prenatal stress on offspring stress hormone levels across a range of characteristics. Remarkably, the effects of prenatal stress on offspring stress hormones were consistent across species, regardless of evolutionary relationships or factors, such as brain or body size. There were also no differences when considering offspring sex, age of the offspring at the time of assessment, or the timing of the stressor exposure prenatally or its severity.
Only two factors influenced the size of the effect. Experimental studies had a stronger effect than observational studies. In addition, studies that measured glucocorticoid recovery showed a greater association with prenatal stress than was observed at baseline or during peak glucocorticoid response.
"Animals, including humans, modify their stress hormones in response to their environment. Your stress response is set like a thermostat -- your body can amp up or down stress hormones in response to anticipated environmental conditions," explains lead author Zaneta Thayer, an assistant professor of anthropology at Dartmouth.
An animal's stress response tends to be activated by external factors, such as when its see a predator or whether food is availabile. Higher stress hormone levels among offspring may help extend survival but come at a cost and may affect other physiological systems, such as reproduction. In humans, the mere anticipation of stress or just thinking about prior experiences of discrimination or trauma can activate a stress response. Overactive stress hormones can lead to chronic health problems in humans, including anxiety, depression and cardiovascular disease.
One of the studies included in the meta-analysis looked at how maternal stress hormones in pregnant snow hares changed in relation to the abundance of their natural predators, lynxes, over a 10-year cycle. The research team found that in years where there were more lynxes, snow hare offspring had more stress hormones and anti-predator behaviors.
"Our stress response is meant to be adaptive to acute stress, such as being chased by predators. However, humans' stress response is often triggered by social evaluative threats and is not serving the adaptive purpose that it was designed for," added Thayer. "This research confirms what other scientists have long speculated that there are trends across species when it comes to linking prenatal stress and offspring hormonal stress responses."
Prior work co-authored by Thayer has explored early origins of humans' health disparities and the impacts of maternal stress during pregnancy on offspring's postnatal stress hormone levels.
Study finds an intergenerational benefit
April 10, 2018
Science Daily/DZNE - German Center for Neurodegenerative Diseases
Physical and mental exercise is not only beneficial for your own brain, but can also affect the learning ability of future offspring -- at least in mice. This particular form of inheritance is mediated by certain RNA molecules that influence gene activity. These molecules accumulate in both the brain and germ cells following physical and mental activity. Prof. André Fischer and colleagues from the German Center for Neurodegenerative Diseases (DZNE) in Goettingen and Munich and the University Medical Center Goettingen (UMG) report these findings in the journal Cell Reports.
Acquired skills do not modify the DNA sequence and therefore cannot be passed on to the offspring -- this belief was prevalent in the field of genetics for a very long time. However, in recent years, scientists have found some circumstances that refute this principle. A poor diet, for example, increases the risk of disease -- not only our own risk, but also that of our children. Lifestyle factors such as stress and trauma can also influence the next generation. Scientists call this phenomenon "epigenetic" inheritance, as it is not associated with changes in DNA sequence.
Inherited learning skills
Prof. André Fischer and colleagues investigated the inheritance of another acquired capacity: the ability for learning. It is well-known that physical and mental activity improves learning ability and reduces the risk of diseases such as Alzheimer's. In mice, the scientists showed that learning ability was passed onto the next generation by epigenetic inheritance. When Fischer and co-workers exposed mice to a stimulating environment in which they had plenty of exercise, their offspring also benefited: compared to the mice of a control group, they achieved better results in tests that evaluate learning ability. These rodents were also found to have improved synaptic plasticity in the hippocampus, a region of the brain important for learning. "Synaptic plasticity" is a measure of how well nerve cells communicate with each other. It thus forms the cellular basis for learning.
Next, the scientists investigated which mechanism could be responsible. For this, they focused on epigenetic inheritance by fathers and looked for its material basis in sperm. Sperm contains paternal DNA and also RNA molecules. The scientists therefore conducted experiments to find out about the role played by these RNA molecules in the inheritance of learning skills. For this, they extracted RNA from the sperm of mice that were physically and mentally active. These extracts were injected into fertilized egg cells. The mice that developed were also found to have enhanced synaptic plasticity and learning ability. Physical and mental activity therefore had a positive effect on the cognitive skills of the offspring. This effect was mediated through the RNA in the sperm.
Tracking down the responsible RNA
In further experiments involving injections of RNA extracts, the scientists were able to more closely identify the RNA molecules responsible for epigenetic inheritance: They showed that two so-called microRNA molecules -- miRNA212 and miRNA132 -- could account for at least some of the inherited learning capacity. microRNAs are control molecules that influence gene activity. "For the first time, our work specifically links an epigenetic phenomenon to certain microRNAs," says Fisher, a senior scientist at the DZNE Goettingen and the UMG.
The researchers also found that miRNA212 and miRNA132 accumulated in the brains and sperm of mice after physical and mental activity. It was previously known that these molecules stimulate the formation of synapses in the brain, thus improving learning ability. Through the sperm, they are transmitted to the next generation. "Presumably, they modify brain development in a very subtle manner improving the connection of neurons. This results in a cognitive advantage for the offspring," says Fischer.
It is known that physical activity and cognitive training also improve learning ability in humans. However, it is not so easy to study in humans whether learning ability can be inherited epigenetically. Nevertheless, the results obtained by Fischer and colleagues may point towards answers to this question. The researchers now intend to find out whether miRNA212 and miRNA132 also accumulate in human sperm after phases of physical and mental activity.