Self and Emotion 199“9x6” b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanityplace in the anterior cingulate cortex on the inner side of the cerebral
hemisphere. Pain fibers from the internal organs pass through the thal-
amus and arrive at the insular cortex, and finally present to the anterior
cingulate cortex to create the sensation of pain. Hypnotic suggestions
to enhance or alleviate emotional pain are correlated with an increase
or decrease in the activity of the anterior cingulate.^42 Watching pictures
of other people suffering also activates this brain area, suggesting its
role in empathy. Interestingly, the anterior cingulate is also activated in
response to pleasant touch, such as caressing.
The neurologic condition called thalamic pain syndrome is seen in
patients suffering from damage to the thalamus, resulting in relentless
pain of a contralateral limb or an entire half of the body. The pain ranges
from dull ache to severe, unremitting burning, is often spontaneous and
is strongly emotional in character. The extreme feeling of unpleasantness
contrasts with the concomitant loss of discriminatory function, such as
telling a sharp from a dull point. An opposite condition is pain asymbo-
lia, found in patients with damage to the insula or anterior cingulate cor-
tex. Although these people can accurately describe the location, nature,
and intensity of the pain stimulus, they lack the emotional response, and
therefore they simply do not suffer.
Another interesting observation is that although pain is unpleasant,
the lessening of pain is actually enjoyable, suggesting the relativity of
pain. As Konrad Lorenz once quipped, there is nothing more pleasur-
able than a diminishing toothache.^43 In contrast, unfulfilled craving for
a rewarding experience could be a tremendous suffering, as in lovesick-
ness. In this sense, pain and pleasure can be viewed as polar extremes
of a continuum. Inside the brain, the interpretation of pain and plea-
sure most likely involves complex, overlapped circuitries of neuronal
crosstalk, including such structures as the ventromedial prefrontal cor-
tex, amygdala, and nucleus accumbens, among other things. I should
emphasize that the function of each structure should not be taken in iso-
lation, but in the context of the overall network. In light of this, it is not
surprising that a single area can be involved in opposite functions. For