OK,
now that got your attention.
It's remarkable what science is revealing to us in
2003. Studies are now helping us understand the
Self, Romantic Love and When not to Trust a Woman!
In the past we have learned that women and men
both lie about three times every 15 minutes. In
simple conversation, women's lies tend to be more
oriented toward protecting feelings of others.
Men's lies have been found to be more oriented to
making themselves look better. A clear win for
women in the values arena. But now...a wrench is
thrown into the whole mix. We now know when women
are going to be less trustworthy.
In new studies, scientists are discovering the
neurobiological underpinnings of romantic love,
trust, and even of self. New research also shows
that a specific brain area - the amygdala - is
involved in the process of understanding the
intentions of others, in particular when lying is
involved. Using brain imaging, researchers Helen
Fisher, Arthur Aron, Lucy Brown and colleagues
find that feelings of intense romantic love are
associated with specific activity in dopamine-rich
brain regions associated with reward and
motivation. Those study participants who expressed
more romantic passion on a questionnaire showed
more brain activity in these regions. Those in
longer relationships showed more activation in
emotion-related areas as well. And men and women
tended to show some different brain responses. The
researchers conclude that romantic love may be
best classified as a motivation system or drive
associated with a range of emotions. Further
studies of intense, early stage romantic love may
help to define how the brain encodes reward and
memory.
In this experiment, 17 young men and women who
had "just fallen madly in love" were
tested with functional magnetic resonance imaging
(fMRI) to identify the brain circuitry of romantic
love.
"We believe romantic love is a developed
form of one of three primary brain networks that
evolved to direct mammalian reproduction,"
says researcher Helen Fisher, PhD, of Rutgers
University in New Brunswick, NJ. "The sex
drive evolved to motivate individuals to seek sex
with any appropriate partner. Attraction, the
mammalian precursor of romantic love, evolved to
enable individuals to pursue preferred mating
partners, thereby conserving courtship time and
energy. The brain circuitry for male-female
attachment evolved to enable individuals to remain
with a mate long enough to complete
species-specific parenting duties."
In the study, participants alternately viewed a
photo of a beloved and a photo of a familiar,
emotionally neutral individual, interspersed with
a distraction task. The researchers hypothesized
that intense early stage romantic love is: (1)
primarily associated with dopamine pathways in the
reward system in the brain; and (2) primarily a
motivation system (as opposed to an emotion)
oriented around planning and pursuit of a
pleasurable reward - an intimate relationship with
a preferred mating partner.
"Our evidence suggests that both
hypotheses are correct," says Lucy Brown,
PhD, of the Albert Einstein College of Medicine in
New York. "We found specific activity in
regions of the right caudate nucleus and right
ventral tegmental area. These brain areas are rich
in dopamine and are part of the brain's motivation
and reward system. Elevated levels of central
dopamine produce energy, focused attention on
novel stimuli, motivation to win a reward and
feelings of elation - some of the core feelings of
romantic love. Activity in other regions changed
also, including one that another imaging study has
shown to became active when people eat
chocolate."
The researchers also found that those who
scored higher on the "Passionate Love
Scale," a questionnaire administered prior to
scanning, also showed more activity in the
caudate. Arthur Aron, PhD, of SUNY Stony Brook,
NY, says, "This result is among the first to
show a direct link between responses to a survey
questionnaire and a specific pattern of brain
activation."
Fisher, Aron, and Brown also found a tendency
toward gender differences. Among them, most of the
women in this study showed more activity in the
body of the caudate, the septum, and posterior
parietal cortex, regions associated with reward,
emotion and attention; most of the men in this
study showed more activity in visual processing
areas, including one associated with sexual
arousal.
Aron, Fisher and Brown have embarked on a
follow-up fMRI study of men and women who have
recently been rejected in love. They wish to
understand the full range of brain systems
associated with this primordial, powerful and
universal human phenomenon.
In another study, Paul Zak, PhD, and his
colleagues at Claremont Graduate University
investigated trust - something that pervades
nearly every aspect of our daily lives. Even so,
the neurobiological mechanisms that permit human
beings to trust each are not understood.
In the new research, Zak and his colleagues
find that when someone observes that another
person trusts them, oxytocin - a hormone that
circulates in the brain and the body - rises. The
stronger the signal of trust, the more oxytocin
increases. In addition, the more oxytocin
increases, the more trustworthy (reciprocating
trust) people are.
"Interestingly, participants in this
experiment were unable to articulate why they
behaved they way they did, but nonetheless their
brains guided them to behave in 'socially
desirable ways,' that is, to be trustworthy,"
says Zak. "This tells us that human beings
are exquisitely attuned to interpreting and
responding to social signals.
The findings are even more surprising because
monetary transfers were used to gauge trust and
trustworthiness, and the entire interaction took
place by computer without any face to face
communication. Signals of trust are sent by
sending money that participants earned to another
person in a laboratory, without knowing who that
person is or what they will do. That, is, there is
a real cost to signaling that you trust someone.
In the experiment, people were recruited and
paid $10 for showing up. Then they took seats in a
large computer lab and were matched up in pairs,
but this was done completely anonymously so that
no one knew (or would know) the other person in
his or her pair. One-half of the participants
(decision-maker 1s) then had the opportunity to
send none, some, or all of their $10 show-up fee
to the other person in their pair. Whatever is
sent is tripled. So, if $4 was sent, the other
person would have $22 ($4 tripled, plus the $10
show-up fee the second person receives). The
second decision-maker could then send some amount
of this money back to decision-maker 1, but need
not. This is how the researchers produced a social
signal of trust: decision-maker 1's only reason to
transfer money to the other person is because he
or she trusts that that person will understand why
the money is being sent to them, and in turn will
return some to them (be trustworthy). All subjects
are told that the initial monetary transfer is
tripled, and there is no deception of any kind.
After each person makes his or her decision,
they were taken to another room and four
tablespoons of blood were taken from an arm vein.
Animal studies have shown that oxytocin, a hormone
little studied in humans, facilitates social
recognition and social bonding, for example,
bonding of mothers to their offspring, and in some
monogamous species the bonding of males and
females in a family unit.
Based on the animal studies, the scientists
hypothesized that what is happening in the trust
experiment is that people are forming temporary
social bonds with the other person in their pair.
"This is just what we found. The stronger the
signal of trust, the more oxytocin increases, and
the more trustworthy people are. This is
surprising given the sterile laboratory
environment of the interaction so that the effect
of oxytocin on face-to-face interactions must be
quite strong," says Zak.
He also found that women in the experiment who
are ovulating were significantly less likely to be
trustworthy (for the same signal of trust). This
effect is caused by the physiologic interactions
between progesterone and oxytocin, and it makes
sense behaviorally: women who are, or are about to
be, pregnant, need to be much more selective in
their interpretation of social signals, and also
need more resources than at other times.
Zak's lab is now studying brain activation
patterns when people receive signals of trust, as
well as in the physiologic responses to trust
signals in patients who have neurological damage.
Trust is an essential part of our daily lives,
from walking down the street to driving to
countless other daily activities, so that
discovering the neurobiology of trust tells us
something important about human nature: that we
are so highly social that we pick up social
signals of trust and act on them even when we are
not consciously aware of these signals. Our brain
acts as an internal compass that guides us towards
the "right" thing to do.
In another imaging study, scientists at
Stanford University located brain areas associated
with self and self relevance. The new work helps
answer questions such as why people hear their own
names in the din of a cocktail party or the fog of
sleep.
In the study, Wemara Lichty, PhD, and her
colleagues used rapid event-related fMRI to
dissociate brain activations related to names.
Sixteen females heard five different auditory
stimuli: 1) a tone; 2) a low frequency name (not
self-relevant), 3) a high frequency name (not
self-relevant), 4) a self-relevant name (e.g.,
sister or best friend), and 5) their own name. To
ensure that participants were attending, they
performed a simple task of pushing a button for
each sound; specifically one button was pressed if
a sound was the same as the preceding one, and a
different button was pressed if the sound was the
same. They listened to a total of 250 sounds over
a period of 12 minutes.
The study was designed to answer the question:
Is there something special about our own name and
the names of those we are close to; i.e., is there
a hint of that relationship in brain activations?
The researchers identified areas special for
personally relevant names compared to
non-personally relevant names: The left medial
prefrontal cortex, an area that has been
associated with self, was active.
"Interestingly, this putative self-related
area was also active in a study for names of close
associates. This suggests that the medial
prefrontal cortex may be involved in processing a
personal network related to the self," says
Lichty. Although imaging studies have not
evaluated this, behavioral studies have shown that
on many cognitive tasks, the performance of self
and close others is often similar and quite
different from that of persons not known. Also
activated was the left posterior cingulate, an
area involved in autobiographical memory.
The study also addressed whether there is
something completely unique about a person hearing
his or her name. Are there areas activated only by
one's own name and not the name of others we know?
Results showed that the right middle temporal
gyrus was active. "This may suggest that the
special status of one's own name is related to
altered cortical perceptual representations.
Enhanced hearing of one's own name may be
associated with decreased thresholds for auditory
cortical activation. However, the activation may
also be related to self as separate from close
others as suggested by the similarity of our area
of activation with the findings of an fMRI study
of activations related to faces of oneself and
one's partner," Lichty says.
She notes that understanding how we differ from
each other and how we are related to each other
can offer insight, both into the essential aspects
of our individual and communal identity.
Clinically, this could be of import regarding
understanding of individuals who may have weak
(underdeveloped, undifferentiated) self. In
addition, it may provide greater insight into
relationships.
Another new study explores the brain mechanisms
involved in deception. What happens when you spot
deception in a human movement? The sort of thing a
hitter tries to do every time a pitcher prepares
to throw a ball.
Working out whether there is deception results
in activation of the amygdala, a structure in the
brain involved in perceiving fear and in learning
about fearful or threatening stimuli. Our new
finding is that the amygdala is also involved in
understanding the intentions of others, in
particular when lying is involved and when actions
are being scrutinized.
"Our study finds a link between emotional
brain systems and the complex brain network used
to read intention in the movements of
others," says Richard Frackowiak, MD, of
University College London. "So, emotional
responses can be driven by factors other than
empathy with someone else's emotions. The
emotional brain responds to an intention to
deceive even when the deception involves a trivial
action."
The clinical importance of this work is for
patients with amygdala damage. For example, there
are abnormalities reported in the amygdalae of
adults with autism. Such patients tend to be
excessively trusting. This may not be to do with
character judgment as such, but with failing to
recognize potential social threats in a stream of
observed actions or gestures.
In a scanning experiment Frackowiak and his
colleagues approached this issue by getting actors
to lift boxes with weights. Sometimes the
experimenter lied to them about the weight in the
box so their movements were likely subtly
modified. Subjects were shown these films while
brain activity was recorded in a scanner and were
asked to rate whether the actor had been deceived
on each occasion.
The researchers specifically compared activity
in subjects' brains when they judged that an actor
was deceived with that when they thought all was
above board in order to isolate brain regions
associated with perceived deception. In future
work these scientists plan to compare situations
in which an actor is trying to deceive a third
party with those in which the actor is trying to
deceive the subjects themselves. This will
indicate whether it is simply the perception of
deception that is important or whether the object
of that deception matters.
Many experiments have been performed using
imaging to study cognitive processes such as
attention, memory or action. But, Frackowiak says
we do not simply base our judgments on reason.
"The amygdala can be regarded as part of our
emotional core system and our results show that we
are deeply affected when we think someone is
trying to deceive us, over even so simple a matter
as the weight of a box. The interaction between
emotion and cognition is thus becoming clarified.
