Neuroscientists Searching For Roots Of Empathy Find Brain Regions Involved
In Learning By Imitation
In a pair of pioneering studies, a French and American team of
social-cognitive
neuroscientists have identified a network of brain regions that are
involved in human
imitation and specific brain areas that enable a person to distinguish the
self from
others.
The research is part of a larger effort to find the neurological basis of
social interaction,
particularly empathy, a basic part of human nature that allows most, but
not all, people
to care about others.
The team is headed by neuroscientist Jean Decety of France뭩 Institut de la
Sant?et
de la Recherche M?icale and a visiting scientist at the University of
Washington뭩
Center for Mind, Brain & Learning, and developmental psychologist Andrew
Meltzoff, co-director of the center.
밫his work is important because imitation is a natural procedure. We don뭪
learn to
imitate. It is part of our biological nature and we are born to imitate,?
said Decety.
밃 3-year-old feels empathy and will pat another child on the shoulder or
comfort his
mom when she뭩 crying,?added Meltzoff. 밯e believe empathy has roots early
in life.
It may be linked to imitation, which we know babies do from a very early
age.?br>
In the two studies, which are being published in the January and February
issues of the
journal NeuroImage, the researchers used positron emission tomography (PET) to
explore the neural mechanisms of imitation by measuring increases in blood
flow in the
brain.
In the first study the researchers look at imitation from the point of view
of a teacher
(the person demonstrating a task) versus the point of view of a student
(the person
learning the task). Eighteen right-handed male subjects were asked to
perform five
tasks involving small, different colored objects. Their heads were held
stationary while
the PET scans made images of their brains, but they could move their right
hands and
watch a demonstrator뭩 hands reflected in a mirror.
Subjects were first asked to watch the demonstrator move the objects and
then imitate
the action with their hand. In the second task, they were told to move the
objects first
and watch the demonstrator copy them. The other three tasks were control
experiments in which subjects were allowed to freely manipulate the objects
any way
they wanted to, just watch the demonstrator move the objects, and move the
objects
and then watch the other person perform different movements.
The researchers discovered a consistent pattern of increased brain activity
involving
the superior temporal gyrus, as well as differential activity in the two
hemispheres
within the inferior parietal cortex when imitation was involved. The left
inferior parietal
cortex showed increased activity when the subjects were imitating another
person.
When the subjects were being imitated by the other person, however, the
right inferior
parietal cortex was more activated.
Decety and Meltzoff believe the inferior parietal cortex may play a key
role in whether
a person attributes an action to the self or to another person.
밄y imitation we may feel what another person felt, which is the very
definition of
human empathy,?said Decety.
밒mitation also is nature뭩 way of conveying culture,?said Meltzoff. 밒t
naturally occurs
in a variety of settings, such as learning to play music and sports, or
when a mother
teaches her daughter how to tie her shoelaces. The mother ties a shoelace
and the
child follows, trying to imitate the action. We would expect the same kind
of lateralized
brain activity in learning to tie shoelaces as there was in our
experimental task.?br>
The second study, which involved 10 right-handed subjects, employed a physical
setup that was similar to the one used in the first study. This time,
however, subjects
were shown video clips of another person choosing, grasping and moving a Lego
block into a new position and then leaving the Lego in the new position.
In the first of six tasks, subjects had to duplicate the entire
manipulation. Next they
were only shown part of a video clip that showed the other person뭩 hand
leaving the
Lego in its final position and the subjects had to manipulate the block to
achieve that
밽oal.?Subjects also viewed a clip that only showed 뱈eans,?or the
manipulations of
a block, and had to duplicate the movements they observed. Three control
tasks also
were performed. Subjects again watched the clips showing the entire
manipulation, as
well as just the goal and the means, and were asked to freely move their
Lego in any
way they choose.
This paper is unique because it is believed to be the first neuroimaging
study to show
that imitation can be split into two complementary components, the goal of
an action
and the means to achieve it.
Decety said the researchers found that not only can the components of
imitation (the
goal and the means) be separated, but each involves specific brain regions.
Increased
brain activity was detected in the medial prefrontal cortex during
imitation of the
means, while increased activity in the left premotor cortex was associated
with
imitation of the goal.
밫his supports the idea that when observing someone뭩 action, the
underlying intention
is equally or perhaps more important than the surface behavior itself,?the
authors
write.
These findings have widespread potential applications in typical and
atypical child
development, educational practice and artificial intelligence.
밒n child development, reading others?goals or intentions from their
actions is
necessary for human interaction. If you are just literal, you will not have
deep
understanding of other people,?said Meltzoff. 밒t is also important to
know what brain
regions control actions and intentions. They may not develop at the same
time in
humans.?br>
밇ducators sometimes pay too much attention to the means without the goal
or to the
goal without giving children the means, or the steps, to accomplish
something,?Decety
said.
The two studies were supported by funding from the French Ministry of
Education and
the UW뭩 Center for Mind Brain & Learning (CMBL). Co-authors of the papers
were Thierry Chaminade and Julie Grezes, doctoral students in France.
CMBL is an interdisciplinary research center where behavioral scientists and
neuroscientists are collaborating to study the links between behavior and
the brain.
The center is funded primarily by the Talaris Research Institute, founded
by a gift from
the Apex Foundation, the private family foundation created by Bruce and Jolene
McCaw.