A researcher puts stickers on a lazy Susan under some
plastic cups, then offers a whirl. A preschooler must find hidden stickers when
the spinning ends. Some kids remember where the stickers are, but some have to
search each cup.
The game measures working memory, one of the group of
behavioral abilities known as executive control that can be compromised in
early-life trauma-facing adolescents.
Adversity wreaks havoc, and from there you have a mechanism
that reacts differently, says Megan Gunnar, a developmental psychobiologist at
Minnesota University in Minneapolis who spent two decades researching the
effects of early-life adversity in adopted kids. This work focuses on acute
hardship, such as being orphaned, rather than regular struggles, which may
teach valuable resilience.
An infancy marked by deprivation, neglect or violence may
also change the neuroendocrine system governing how the body reacts to stress.
Stress response issues will put children on a road to developmental challenges
along with increased risk of adhd, diabetes, and a host of other health
concerns.
Yet new reports indicate that a daunting future might not be
necessary. As Gunnar and others have demonstrated, disrupted stress responses
can revert to normal during puberty, making it easier to remove imbalances
produced by early trauma. Research is encouraging a new understanding of
puberty as an opportunity — a chance for adults with a weak beginning to change
their physiological responses to stress.
A sense of safety
When the brain perceives a threat — even a fleeting one,
such as a painful test or a high-stakes competition — levels of hormone
adrenaline shot up , causing the "fight-or - flight" reflex. Breathing
and pace ascend. Palms hot. See and sharpen senses. The brain sends chemical
messengers to activate adrenal glands near the kidneys to release cortisol.
Cortisol transfers sugars to blood for quick energy. In a
fight-or - flight case, the hormone often delays metabolism, immune responses,
development and other functions considered non-essential.
The fight-or - flight response stops when the danger
disappears, at least in a person whose stress response functions as it should.
Levels of adrenaline and cortisol drops, pulse rate slows, and other processes
continue business as normal.
When Gunnar began her doctoral study in the 1970s ,
researchers already figured out main players in the stress response. Involved
neuroendocrine impulses form the HPA axis, short for
hypothalamic-pituitary-adrenal. When rodents and monkeys face early difficulty,
the HPA axis is knocked off-kilter. When techniques were possible to quantify
cortisol from saliva samples — rather than extracting blood or urine — Gunnar
set out to research how the HPA axis affects human brain and conduct.
From mid-1980s studies with newborn babies, Gunnar found
that having a stable parent relationship is crucial for a healthy
neuroendocrine system and helps babies cope with challenging conditions such as
getting immunizations. You can go to the hospital as a infant and have a huge
shot in one leg and the other leg, and you're tearing off your back ... but it
doesn't take off, says Gunnar. But if babies are separated from their parents
for even a few minutes, their HPA axis rockets up like a missile.
Gunnar wonders what happens if the long-term feeling of
protection is broken. She attempted to research neglected and deprived
children, but distinguishing the consequences of early deprivation from later
problems is not straightforward. "The way you start life seems to
continue," says Gunnar. A US-published paper last November. Centers on
Disease Control and Prevention refers to the long-term effects of smoking,
drinking excessively, dropping out of high school and having heart disease and a
host of other health problems relative to their peers.
A mid-1990s trip put Gunnar on a new direction to address
the troublesome study issue. She went to an orphanage in eastern Romania with a
study team, where children were living in overcrowded, barbaric circumstances.
You step into these wards, and immediately you're mobbed by kids shouting 'Mom,
Mom, Mom' ... stretching their arms to get hold, says Gunnar, who at the time
had two school-age sons. It was bad. I just tried to get them home.
What she carried back to Minnesota was a series of small
vials, each holding a saliva sample from a 2- or 3-year-old orphan. To her
dismay, cortisol levels in kids — the end result of the neuroendocrine cascade
— were smaller than the normal people. The study provided a window on long-term
parental neglect effects on stress responses.
Adoptee struggles
To recognise the impact of early adversity, Gunnar wanted
kids who began out in misery but migrated to stable, nurturing environments
after infancy. Such kids will be the perfect model for all early adversity
animal experiments, she thought. It dawned that this community exists: orphans
adopted.
Gunnar shared her proposal with employees of the Minnesota
Human Services Department's adoption team. With support and funds from the
agency, she surveyed Minnesota parents who had adopted children abroad in the
1990s, encouraging families to enter a university registry and engage in
research.
Many research parents had found early that their adoptive
children had behavioural issues. And when the kids came to the university lab
for problem-solving and sorting exercises, including the lazy Susan challenge
and the successful marshmallow test of delayed gratification, the kids
struggled with treatment and self-regulation.
Like Romanian orphans, these kids had lower amounts of
cortisol than children who had no behavioural issues. Gunnar speculates that in
the face of prolonged suffering, which has the potential to promote excessively
high levels of cortisol, a poor stress response — that is, generating less
cortisol — could be the way nature protects the brain and body.
Teen-time shift
Adopted children who grew up with early-life abuse (gray
curve) before puberty had blunted stress responses compared to children with
birth parents (blue curve). Before, after and after a challenging mission, the
adopted kids showed regular cortisol levels. Saliva was extracted 20 minutes
before the mission, 5, 20, 40, 60 and 80 minutes after the assignment.
Researchers translated data to a logarithmic scale, displaying negative
figures. Cortisol amounts range between 0 and 1 microgram per deciliter.
Studying adoptees over time, she noticed that
care-probleming preschoolers with low cortisol often reached kindergarten. A
blunted stress response continued in middle childhood, even after an average
seven or eight years in a safe care home.
That was disheartening, says Russell Romeo, Barnard College
psychobiologist in New York City. We 'd always figured they would start
recalibrating their stress reactivity once they get out of stressful
circumstances.
But Romeo 's study in the mid-2000s gave Gunnar cause to believe
she wanted to look deeper into the direction of children's lives.
High time for change
Romeo examined rats to see how depression influences teenage
and adult brains differently. In one series of tests, he exposed adult rats and
prepubescent rats to acute stress — 30 minutes stuck inside a wire mesh jar —
and reported their corticosterone levels (cortisol rat version) before, during
and after confinement. Both groups developed similar hormone spikes when
stressed, but levels in juvenile rats took much longer to normalize.
When Romeo studied how animals responded to long stress
periods—30 minutes of seven-day restriction per day — the behavior was
different. Since freeing the animals from the chains, tension hormones spiked
higher in young rats than in adults. Yet rats near puberty returned to baseline
quicker than older males. Taken together, research by Romeo proposed
neuroendocrine stress responses were formed during adolescence to appear
differently in adulthood.
In earlier studies , researchers at McGill University in
Montreal found that transferring teenage rats to enriched environments — larger
cages with more toys and cagemates — could reset stress mechanisms that
early-life deprivation had thrown out of whack.
Ses results inspired Gunnar. Maybe I'd look into puberty,
she figured. It may be recalibrating time.
Closer to normal
During traumatic behavior (such as speaking), saliva
cortisol levels increased briefly and returned to usual among those children
who stayed with their biological parents. Children adopted from childhood in an
orphanage (an early-life trauma) had blunted cortisol responses at stages 1 to
2 of puberty. Yet at the rear end of puberty, stages 4 and 5, accepted
standardized infant stress responses.
Thus, her team welcomed 280 7- to 14-year-olds—122
youngsters adopted from organizations and 158 from social comparable maternal
families — to the laboratory to perform two challenging tasks. One was
demanding theoretical arithmetic. For the second assignment, each pupil
practiced a five-minute speech announcing a new student class. Children were
told their voice, presented in front of a video camera and mirror, would be
judged. Some kids talked enthusiastically, others seemed anxious. We had one
break into laughter, Gunnar says. So we're not torturing them. If we find they
're too anxious, we 're making them leave.
Before and during each child's speech and math activities,
researchers gathered saliva samples to test cortisol levels. The pubertal
status of the participants was measured on a 1-to-5 scale: stage 1 meant no
visible body modifications and stage 5 meant full sexual maturation.
Both early puberty kids (stages 1–2), adoptive kids had
blunted cortisol levels before and after the activities similar to kids living
with their biological parents. This finding validated Gunnar 's previous
pre-school-age foreign adoption study. Cortisol trends in late puberty group
(stages 4–5) appeared identical for adopted and unadopted adolescents.
In order to confirm HPA recalibration, instead of simply
contrasting across age groups, Gunnar and colleagues took participants for the
same assessments one and two years later, for a total of three annual sessions.
Matthew Duggan, a Long Beach, California psychiatrist
working in childhood and puberty, is inspired by results and feels they could
relate to a wide variety of children who have difficulty controlling their
feelings and communicating with others when parents neglected or overlooked
them early in life. There may be a chance ... where things may change, Duggan
says. And we have some evidence to show that this is a probability at biological
stage. That's very optimistic for me.
Duggan suggests Gunnar 's study would have been even more
beneficial if it had measured the change in behavior of participants — for
example, by questioning parents , teachers, or teenagers themselves.
How can puberty combine better treatment and help to reshape
neuroendocrine stress responses? Romeo speculates that stems from the fact that
the hypothalamus and other brain areas, such as the prefrontal cortex, that
regulate our stress reactions are among the regions that rewire and establish
associations throughout adolescence.
It's impossible to tell whether these changes in the stress
response will actually benefit a young person, Gunnar says. Mental wellbeing
and endurance arise from an ever-changing mix of genes and social experiences —
some of which early bring the body awry. But puberty may probably remove any
harm, her research reveals. Gunnar and others intend to discover more of the
fundamental reboot biology.
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