محبت ورزی به کودک در اوان زندگی ممکن است به او کمک نمايد تا هیپوکامپ، منظقه ای مهم در مغز درگیر با یادگیری، حافظه و واکنش در برابر فشارهای عصبی، بزرگتر شود، این نتیجه گیری یك پژوهش تازه است.
پژوهش های حیوانی در گذشته نشان داد که پشتیبانی مادرانه در رشد هیپوکامپ، تولید سلول های مغزی، و توانایی مقابله با فشارها تاثیر مثبتی بر موش های جوان دارد. از طرف دیگر، مطالعه ها در مورد كودكان انسان ارتباطی میان تجربه های اوان كودكی و حجم آمیگدالا، كه به تنظیم پردازش و ثبت واكنش های احساسی كمك می كند، یافت. مطالعه های پر شماری نیز نشان داد كودكانی كه در یك محیط محبت آمیز پرورش می یابند از نظر آموزشی و احساسی، در مقایسه با دوستانشان كه در محیط بی محبتی زندگی می كنند، عموما عملكرد بهتری دارند.
تصویربرداری های مغزی اكنون فاش ساخت كه عشق مادر حجم فیزیكی هیپوكامپ فرزند را تغییر می دهد. در این مطالعه، حجم هیپوكامپ كودكان مادران محبت ورز، در مقایسه با كودكانی كه مادران آنها كمتر محبت می كردند، 10 درصد بزرگتر بود. پژوهش ها چنین القا كرده است كه میان هیپوكامپ بزرگتر و حافظه بهتر پیوندی وجود دارد.
دكتر جان لوبی، پژوهشگر اصلی این مطالعه و یك روانپزشك در دانشكده پزشكی دانشگاه واشینگتن در سنت لوییس، میسوری، گفت: "ما اكنون می توانیم با اطمینان بگوییم كه محیط روانی-اجتماعی تاثیر مادی (ملموسی) بر چگونگی رشد مغز انسان دارد. این یافته توان حركتی تازه ای به نظری می دهد كه می گوید پرورش محبت ورزانه كودكان در دوران ابتدایی زندگی آنها تاثیر مثبتی بر رشدشان دارد." [ادامه در زیر ...]
How a Mother's Love Changes a Child's Brain
By Joseph Castro | LiveScience.com – Jan. 30, 2012
Nurturing a child early in life may help him or her develop a larger hippocampus, the brain region important for learning, memory and stress responses, a new study shows.
Previous animal research showed that early maternal support has a positive effect on a young rat's hippocampal growth, production of brain cells and ability to deal with stress. Studies in human children, on the other hand, found a connection between early social experiences and the volume of the amygdala, which helps regulate the processing and memory of emotional reactions. Numerous studies also have found that children raised in a nurturing environment typically do better in school and are more emotionally developed than their non-nurtured peers.
Brain images have now revealed that a mother’s love physically affects the volume of her child’s hippocampus. In the study, children of nurturing mothers had hippocampal volumes 10 percent larger than children whose mothers were not as nurturing. Research has suggested a link between a larger hippocampus and better memory.
"We can now say with confidence that the psychosocial environment has a material impact on the way the human brain develops," said Dr. Joan Luby, the study's lead researcher and a psychiatrist at the Washington University School of Medicine in St. Louis, Mo. "It puts a very strong wind behind the sail of the idea that early nurturing of children positively affects their development."
The research is part of an ongoing project to track the development of children with early onset depression. As part of the project, Luby and her colleagues previously measured the maternal support that children — who were ages 3 to 6 and had either symptoms of depression, other psychiatric disorders or no mental health problems — received during a so-called "waiting task."
The researchers placed mother and child in a room along with an attractively wrapped gift and a survey that the mother had to fill out. The children were told they could not open the present until five minutes had passed — basically until their mothers had finished the survey. A group of psychiatrists, who knew nothing about the children's health or the parents' temperaments, rated the amount of support the mothers gave to their children.
A mother who was very supportive, for example, would console her child, explaining that the child had only a few more minutes to wait and that she understands the situation was frustrating. "The task recapitulates what everyday life is like," Luby told LiveScience, meaning that it gives researchers an idea of how much support the child receives at home.
Now, four years later, the researchers gave MRI (magnetic resonance imaging) scans to 92 children who underwent the waiting task. Compared with non-depressed children with high maternal support, non-depressed children with low support had 9.2 percent smaller hippocampal volumes, whiledepressed children with high and low support had 6.0 and 10.6 percent smaller volumes, respectively.
Though 95 percent of the parents in the study were the children's biological mothers, the researchers say that the effects of nurturing on the brain are likely to be the same for any primary caregiver. [Why Gay Parents May Be the Best Parents]
Luby and her team will continue following the children as they grow older, and plan to see how other brain regions are affected by parental nurturing during preschool years.
"It's now clear that a caregiver's nurturing is not only good for the development of the child, but it actually physically changes the brain," Luby said.
The study was published online today (Jan. 30) in the journal Proceedings of the National Academy of Sciences.
Mom’s Love Good for Child’s Brain
NewsWise | Released: 1/30/2012 11:50 AM EST
Embargo expired: 1/30/2012 3:00 PM EST
Source: Washington University in St. Louis
Description
School-age children whose mothers nurtured them early in life have brains with a larger hippocampus, a key structure important to learning, memory and response to stress. The new research, by child psychiatrists and neuroscientists at Washington University School of Medicine in St. Louis, is the first to show that changes in this critical region of children’s brain anatomy are linked to a mother’s nurturing.
Newswise — School-age children whose mothers nurtured them early in life have brains with a larger hippocampus, a key structure important to learning, memory and response to stress.
The new research, by child psychiatrists and neuroscientists at Washington University School of Medicine in St. Louis, is the first to show that changes in this critical region of children’s brain anatomy are linked to a mother’s nurturing.
Their research is published online in the Proceedings of the National Academy of Sciences Early Edition.
“This study validates something that seems to be intuitive, which is just how important nurturing parents are to creating adaptive human beings,” says lead author Joan L. Luby, MD, professor of child psychiatry. “I think the public health implications suggest that we should pay more attention to parents’ nurturing, and we should do what we can as a society to foster these skills because clearly nurturing has a very, very big impact on later development.”
The brain-imaging study involved children ages 7 to 10 who had participated in an earlier study of preschool depression that Luby and her colleagues began about a decade ago. That study involved children, ages 3 to 6, who had symptoms of depression, other psychiatric disorders or were mentally healthy with no known psychiatric problems.
As part of the initial study, the children were closely observed and videotaped interacting with a parent, almost always a mother, as the parent was completing a required task, and the child was asked to wait to open an attractive gift. How much or how little the parent was able to support and nurture the child in this stressful circumstance — which was designed to approximate the stresses of daily parenting — was evaluated by raters who knew nothing about the child’s health or the parent’s temperament.
“It’s very objective,” Luby says. “Whether a parent was considered a nurturer was not based on that parent’s own self-assessment. Rather, it was based on their behavior and the extent to which they nurtured their child under these challenging conditions.”
The study didn’t observe parents and children in their homes or repeat stressful exercises, but other studies of child development have used similar methods as valid measurements of whether parents tend to be nurturers when they interact with their children.
For the current study, the researchers conducted brain scans on 92 of the children who had had symptoms of depression or were mentally healthy when they were studied as preschoolers. The imaging revealed that children without depression who had been nurtured had a hippocampus almost 10 percent larger than children whose mothers were not as nurturing.
“For years studies have underscored the importance of an early, nurturing environment for good, healthy outcomes for children,” Luby says. “But most of those studies have looked at psychosocial factors or school performance. This study, to my knowledge, is the first that actually shows an anatomical change in the brain, which really provides validation for the very large body of early childhood development literature that had been highlighting the importance of early parenting and nurturing. Having a hippocampus that’s almost 10 percent larger just provides concrete evidence of nurturing’s powerful effect.”
Luby says the smaller volumes in depressed children might be expected because studies in adults have shown the same results. What did surprise her was that nurturing made such a big difference in mentally healthy children.
“We found a very strong relationship between maternal nurturing and the size of the hippocampus in the healthy children,” she says.
Although 95 percent of the parents whose nurturing skills were evaluated during the earlier study were biological mothers, the researchers say that the effects of nurturing on the brain are likely to be the same for any primary caregiver — whether they are fathers, grandparents or adoptive parents.
The fact that the researchers found a larger hippocampus in the healthy children who were nurtured is striking, Luby says, because the hippocampus is such an important brain structure.
When the body faces stresses, the brain activates the autonomic nervous system, an involuntary system of nerves that controls the release of stress hormones. Those hormones help us cope with stress by increasing the heart rate and helping the body adapt. The hippocampus is the main brain structure involved in that response. It’s also key in learning and memory, and larger volumes would suggest a link to improved performance in school, among other things.
Past animal studies have indicated that a nurturing mother can influence brain development, and many studies in human children have identified improvements in school performance and healthier development in children raised in a nurturing environment. But until now, there has not been solid evidence linking a nurturing parent to changes in brain anatomy in children.
“Studies in rats have shown that maternal nurturance, specifically in the form of licking, produces changes in genes that then produce changes in receptors that increase the size of the hippocampus,” Luby says. “That phenomenon has been replicated in primates, but it hasn’t really been clear whether the same thing happens in humans. Our study suggests a clear link between nurturing and the size of the hippocampus.”
She says educators who work with families who have young children may improve school performance and child development by not only teaching parents to work on particular tasks with their children but by showing parents how to work with their children.
“Parents should be taught how to nurture and support their children,” Luby says. “Those are very important elements in healthy development.”
Luby JL, Barch DM, Belden A, Gaffrey MS, Tillman R, Babb C, Nishino T, Suzuki H, Botteron KN. Maternal support in early childhood predicts larger hippocampal volumes at school age. Proceedings of the National Academy of Sciences Early Edition, Jan. 30, 2012. www.pnas.org/cgi/doi/10.1073/pnas.1118003109.
Funding for this research comes from grants awarded by the National Institute of Mental Health of the National Institutes of Health (NIH).
Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.