How do we empathize with others? A mechanism
according to which action representation
modulates emotional activity may provide an
essential functional architecture for empathy.
The superior temporal and inferior frontal
cortices are critical areas for action
representation and are connected to the limbic
system via the insula. Thus, the insula may be a
critical relay from action representation to
emotion. We used functional MRI while subjects
were either imitating or simply observing
emotional facial expressions. Imitation and
observation of emotions activated a largely
similar network of brain areas. Within this
network, there was greater activity during
imitation, compared with observation of
emotions, in premotor areas including the
inferior frontal cortex, as well as in the
superior temporal cortex, insula, and amygdala.
We understand what others feel by a mechanism of
action representation that allows empathy and
modulates our emotional content. The insula
plays a fundamental role in this mechanism.
The manifold
nature of interpersonal relations: the quest for
a common mechanism.
Gallese
Vittorio - Intituto di
Fisiologia Umana, Universita di Parma, Italy.
website
for pdf
Trans R Soc Lond B Biol Sci 2003 Mai
29;358(1431):517-28
It has been proposed that the capacity to
code the 'like me' analogy between self and
others constitutes a basic prerequisite and a
starting point for social cognition. It is by
means of this self/other equivalence that
meaningful social bonds can be established, that
we can recognize others as similar to us, and
that imitation can take place. In this article I
discuss recent neurophysiological and brain
imaging data on monkeys and humans, showing that
the 'like me' analogy may rest upon a series of
'mirror-matching' mechanisms. A new conceptual
tool able to capture the richness of the
experiences we share with others is introduced:
the shared manifold of intersubjectivity. I
propose that all kinds of interpersonal
relations (imitation, empathy and the
attribution of intentions) depend, at a basic
level, on the constitution of a shared manifold
space. This shared space is functionally
characterized by automatic, unconscious embodied
simulation routines.
Preliminary observations of stroke patients
with problems relating emotionally to others
suggest that in order to feel empathy, people
must be able to imitate the actions of others.
In other words, to understand what others are
feeling, you must put yourself physically in
their shoes.
Stroke can damage any area of the brain, but
the patients in question all have lesions to one
particular brain structure - the insula, which
lies between the frontal and temporal lobes on
both sides of the brain.
On tests of their ability to gauge the
emotions being experienced by people from their
facial expressions in photographs, these
patients perform very poorly compared to healthy
controls.
The study, which is being carried out by
neurologist Gian Luigi Lenzi and his colleagues
at La Sapienza University in Rome, Italy, is
preliminary because damage to the insula in the
brain's left hemisphere can also extend to
language areas, affecting the patient's ability
to communicate and hence potentially masking any
separate, emotional impairment.
But if the insula does turn out to be the
key to their emotional deficit, it would fit
very well with data that Lenzi and his
collaborators at the Ahmanson-Lovelace Brain
Mapping Center at the University of California,
Los Angeles published last month in the
Proceedings of the National Academy of Sciences,
on the neural correlates of empathy.
They scanned people's brains using
functional Magnetic Resonance Imaging while they
either observed or imitated images of facial
expressions of emotion. In both tasks, they
found activation of the limbic system, which is
key to the processing of emotion.
But in the imitation task, they also found
activation of the brain's mirror or imitation
circuit, which is stimulated both by the
observation and execution of an action, and of
the insula. The limbic system was also
significantly more active during this task.
According to one of the UCLA researchers,
Marco Iacoboni, the findings suggest that
empathy, or the ability to feel the emotions of
others, is correlated with the degree to which
one mimics their behavior.
The findings contradict the longheld view
that an intellectual, computer-like brain
generates empathy within itself, suggesting
instead that "a brain needs a body to understand
other brains," he says. And they also support
behavioral studies relating to the phenomenon of
emotional contagion, or the chameleon effect, in
which people unthinkingly adopt the postures and
mannerisms of those around them.
"People who tend to subconsciously and
automatically imitate the postures and
mannerisms of other individuals also tend to be
concerned about the feelings of other people,"
said Iacoboni.
He thinks that the insula could play a
pivotal role in this imitation-empathy
mechanism, relaying information from the mirror
circuit to the limbic system. In terms of its
location in thebrain and its connectivity, he
thinks it is ideally placed to do so. Although
empathy is a complex phenomenon, he believes
that a kind of "emotional resonance" might be a
first step towards it, that is achieved through
imitation and the activity of the insula. By
teaching autistic children to imitate the
expressions of others, he speculates that it
might be possible to encourage them to develop
the emotional understanding of others, which
they lack - this will be the goal of his next
research project.
But Jonathan Cole, a clinical
neurophysiologist at Poole Hospital in Dorset,
UK, is dubious. He has studied patients with
Möbius syndrome, who congenitally lack
facial expression. Although other studies have
produced conflicting results, he says that his
work suggests that the ability of such patients
to recognize emotional facial expressions in
others is "not that bad."
Andrew Meltzoff, a developmental
psychologist at the University of Washington's
Center for Mind, Brain and Learning in Seattle,
says the UCLA group's work is "admirable", but
that it is important to distinguish between
emotional contagion and true empathy, which is
different in that it involves the capacity to
hold both your own emotional state and another's
simultaneously - rather than to just "catch"
their emotion and feel it as your own.
He believes, on the basis of his research in
infants, that emotional contagion precedes
empathy in developmental terms. And that
preceding both of these, in the very youngest
newborn babies, is the ability to imitate
another's actions and expressions.
"Neuroscience has not fully cracked the
brain basis of the mature adult feelings of
empathy, but we are getting close," said
Meltzoff. Image caption - 3D image of the brain
seen from below. Three solid objects correspond
to the posterior part of inferior frontal
cortex, a mirror area important for imitation
(green), the anterior insula (blue), and the
amygdala, one of the emotional centers of the
brain (yellow). Kindly provided by Marco
Iacoboni, UCLA.
Characterization of
Empathy Deficits following Prefrontal Brain
Damage: The Role of the Right Ventromedial
Prefrontal Cortex
Shamay-Tsoory, S. G., R. Tomer, et al.
J Cogn Neurosci 2003; 15; 3; 324-37
Impaired empathic response has been described
in patients following brain injury, suggesting
that empathy may be a fundamental aspect of the
social behavior disturbed by brain damage.
However, the neuroanatomical basis of impaired
empathy has not been studied in detail. The
empathic response of patients with localized
lesions in the prefrontal cortex (n = 25) was
compared to responses of patients with posterior
(n = 17) and healthy control subjects (n = 19).
To examine the cognitive processes that underlie
the empathic ability, the relationships between
empathy scores and the performance on tasks that
assess processes of cognitive flexibility,
affect recognition, and theory of mind (TOM)
were also examined. Patients with prefrontal
lesions, particularly when their damage included
the ventromedial prefrontal cortex, were
significantly impaired in empathy as compared to
patients with posterior lesions and healthy
controls. However, among patients with posterior
lesions, those with damage to the right
hemisphere were impaired, whereas those with
left posterior lesions displayed empathy levels
similar to healthy controls. Seven of nine
patients with the most profound empathy deficit
had a right ventromedial lesion. A differential
pattern regarding the relationships between
empathy and cognitive performance was also
found: Whereas among patients with dorsolateral
prefrontal damage empathy was related to
cognitive flexibility but not to TOM and affect
recognition, empathy scores in patients with
ventromedial lesions were related to TOM but not
to cognitive flexibility. Our findings suggest
that prefrontal structures play an important
part in a network mediating the empathic
response and specifically that the right
ventromedial cortex has a unique role in
integrating cognition and affect to produce the
empathic response.
