THE MOLECULE OF MOREA PSYCHOTIC SHORT CIRCUITWhat happens, though, if the salience function of the brain
malfunctions—if it goes off even when there is nothing happening that
is actually important to you? Imagine you’re watching the news. The
anchorman is talking about a government spying program, and sud-
denly your salience circuit fires for no reason at all. You might then
believe that this story on the news has something to do with you. Too
much salience, or any salience at all at the wrong time, can create delu-
sions. The triggering event rises from obscurity to importance.
A common delusion among people with schizophrenia is that peo-
ple on TV are talking directly to them. Another is that they are the
target of investigation by the NSA, FBI, KGB, or Secret Service. One
patient said he saw a stop sign, and thought it was a message from his
mother telling him to stop looking at women. Another patient saw a
red car parked outside her apartment on Valentine’s Day, and believed
it was a message of love from her psychiatrist. Even people who have
never been psychotic might learn to attach salience to things that appear
unimportant to others, such as black cats or the number 13.^2
There’s wide variation in how much salience different people attach
to different things. Everyone has a lower limit, though. We have to cat-
egorize some things as having low salience, being unimportant, so we
can ignore them for the simple reason that noticing every detail in the
world around us would be overwhelming.
BLOCKING DOPAMINE TO
TREAT PSYCHOSISPeople with schizophrenia control their dopamine activity by
taking medications that block dopamine receptors (Figure 4).2 Is superstition a very mild form of delusion, or is it a choice? Research indicates
that superstitious people have a preponderance of dopaminergic traits, so there is
probably a genetic tendency for some people to adopt superstitious beliefs.