“Our subjects experienced this [body-swap] illusion as being exciting and strange,
and often said that they wanted to come back and try it again.” — VALERIA PE TKOVA
after 20 years
Some long-married couples
are as giddy as teenagers
By Laura Sanders
New research on brain activity confirms
that people can be madly in love with
each other long after the honeymoon
Researchers led by Bianca Acevedo of
the Albert Einstein College of Medicine
in New York wanted to know if romantic
love — or at least the brain activity it triggers — could last. To everyone’s relief, the
answer is yes.
People who report being madly in
love for an average of 21 years maintain
activation in a brain region associated
with early-stage love, the researchers
Using fMRI, Acevedo and colleagues
monitored the brain activity of long-term
lovers while they viewed pictures of their
partners. The researchers were particularly interested in a small group of people
who had been with the same person for
many years and claimed to still feel the
excitement of the early days.
People who had been experiencing
intense love for 20 years and people who
had been in love for only months showed
similar activation in the ventral tegmental area of the brain — a region known to
be activated during the intense, burning
stages of early love. The same area is activated by the rush of cocaine.
At the same time, key differences
between the early- and late-stage lovers
emerged. People in long-term relationships showed higher levels of activity in
a part of the brain associated with calmness and pain suppression, whereas people in love for shorter periods had higher
activity in a region associated with obsession and anxiety.
“The difference is that in long-term
love, the obsession, the mania, the anxiety has been replaced with calm,” says
study coauthor Helen Fisher of Rutgers
University in New Brunswick, N.J.
“There is an evolutionary advantage to
being paired,” says researcher J. Thomas
Curtis, who studies pair-bonding in prairie voles, which are known for forming
lifelong monogamous pairs.
Much of the research on voles, including Curtis’ work at Oklahoma State University in Tulsa, supports these new
findings, he says. In fact, when researchers get rid of the ventral tegmental area
of a vole brain, the animal no longer
forms pair bonds.
get into the cat, Toxo tricks rats into
acting recklessly. A team led by Patrick
House at Stanford University reported
that they have identified two distinct
regions of the brain, one important
for fear and the other responsible for
attraction, that are activated in Toxo-
infected rats after they smell cat odor.
Surprisingly, the attraction region
of the rat brain is similarly activated
when a male rat encounters a female,
suggesting that Toxo may fool the rat
into mistaking cat urine for a sign of a
potential mate. — Laura Sanders
Anatomy of a well-aging brain
People who are mentally vigorous at
age 80 can have more plaques in
their brains than their normal-aging
counterparts. At the same time, these
higher-performing brains may host fewer
tangles, which are denser, more harmful
protein clumps, researchers reported.
Plaques are diffuse clumps of proteins in the brain, and clumps of the
protein amyloid-beta are often associ-
ated with Alzheimer’s disease. The finding could spur research into possible
benefits of having plaques, says study
leader Changiz Geula of Northwestern
University. One guess is that plaques
may serve as safe repositories for
harmful proteins that would otherwise
float around in the brain, Geula adds.
This preliminary finding comes from
a study called the SuperAging Project,
which departs from the traditional way
of studying the aging brain. Instead of
examining the brains of people who
suffer from age-related diseases such
as Alzheimer’s and Parkinson’s— what
Geula calls “shrinkers” —the team
wants to figure out what happens in the
brains of people who age well.
— Laura Sanders
Melatonin by moonlight
Moonlight may interrupt astronauts’
sleep cycles by messing with their
melatonin, researchers reported. Sleep
cycles are regulated by the type and
amount of light that people encounter.
When a person goes to sleep, the hormone melatonin circulates through the
body to maintain a drowsy state. But if a
light comes on, the body’s melatonin levels drop, causing the person to wake up.
Astronauts are notoriously bad sleepers, says Benjamin Warfield of Thomas
Jefferson University in Philadelphia. They
average just four to six hours of sleep
a night when they’re on a mission and
amass a huge sleep deficit. But no one
knew how moonlight might affect this
chronic lack of sleep.
To figure it out, Warfield and his colleagues built a piece of equipment they
call the Moonlight Machine —a complicated series of lights, mirrors, lenses
and filters —to mimic moonlight conditions experienced by astronauts. Subjects sat inside the Moonlight Machine
between 2 a.m. and 3: 30 a.m., a time
when melatonin levels in the body are
normally high. The researchers found
that melatonin levels were diminished
after the moonlight exposure.