For
you to stay healthy, each system in your body and mind must balance two
conflicting needs. On the one hand, it must remain open to inputs during
ongoing transactions with its local environment (Thompson 2007); closed systems
are dead systems. On the other hand, each system must also preserve a
fundamental stability, staying centered around a good set-point and within
certain ranges—not too hot, nor too cold.
For
example, inhibition from the prefrontal cortex (PFC) and arousal from the
limbic system must balance each other: too much inhibition and you feel numb
inside, too much arousal and you feel overwhelmed. Signals of Threat To keep
each of your systems in balance, sensors register its state (as the thermometer
does inside a thermostat) and send signals to regulators to restore equilibrium
if the system gets out of range (i.e., turn the furnace on or off).
Most
of this regulation stays out of your awareness. But some signals for corrective
action are so important that they bubble up into consciousness. For example, if
your body gets too cold, you feel chilled; if it gets too hot, you feel like
you’re baking.
These
consciously experienced signals are unpleasant, in part because they carry a
sense of threat—a call to restore equilibrium before things slide too far too
fast down the slippery slope. The call may come softly, with a sense of unease,
or loudly, with alarm, even panic.
However
it comes, it mobilizes your brain to do whatever it takes to get you back in
balance. This mobilization usually comes with feelings of craving; these range
from quiet longings to a desperate sense of compulsion. It is interesting that
the word for craving in Pali—the language of early Buddhism—is tanha, the root
of which means thirst. The word “thirst” conveys the visceral power of threat
signals, even when they have nothing to do with life or limb, such as the
possibility of being rejected.
Threat
signals are effective precisely because they’re unpleasant—because they make
you suffer, sometimes a little, sometimes a lot. You want them to stop.
--Rick
Hanson, Buddha's Brain: The Practical Neuroscience of Happiness, Love, and
Wisdom
