Download - IndexUniverse.com

targets; instead, these neural connections shoot forth their bursts
like fireworks, sending vast sprays of energy throughout the parts
of the brain that turn motivations into decisions and decisions
into actions. It can take as little as a twentieth of a second for
these electrochemical pulses to blast their way up from the base
of your brain to your decision centers.
In the popular mind, dopamine is a pleasure drug that
gives you a natural high, an internal Dr. Feelgood flooding
your brain with a soft euphoria whenever you get something
you want. There’s more to it than that. Besides estimating
brains of monkeys earning “income” like sips of juice or morsels
of fruit, Schultz confirmed that when a reward comes as a
surprise, the dopamine neurons fire longer and stronger than
they do in response to a reward that was signaled ahead of
time. In a flash, the neurons go from firing 3 times a second
to as often as 40 times per second. The faster the neurons
fire, the more urgent the signal of reward they send.
“The dopamine system is more interested in novel stimuli
than familiar ones,” explains Schultz. If you earn an unlikely
financial gain—let’s say you make a killing on the stock of
Without the rush of dopamine … “we modern”
investors would keep all our money under the mattress.
the value of an expected reward, you also need to propel
yourself into the actions that will capture it. “If you know that
a reward might happen,” says psychologist Kent Berridge of
the University of Michigan, “then you have knowledge. If you
find that you can’t just sit there, but that you must do something,
then that’s adding power and motivational value to
knowledge. We’ve evolved to be that way, because passively
knowing about the future is not good enough.”
Researchers Schultz and Read Montague, along with Peter
Dayan, now at University College London, have made three
profound discoveries about dopamine and reward:
1. Getting what you expected produces no dopamine kick.
A reward that matches expectations leaves your dopamine
neurons in a kind of steady-state hum, sending out electrochemical
pulses at their resting rate of around three bursts
per second. Even though rewards are meant to motivate you,
getting exactly what you expected is neurally unexciting.
That may help explain why drug addicts crave an ever-larger
“fix” to get the same kick—and why investors have such a
hankering for fast-rising stocks with “positive momentum” or
“accelerating earnings growth.” To sustain the same level of
neural activity, they require a bigger hit each time.
2. An unexpected gain fires up the brain. By studying the
a risky new biotechnology company, or you strike it rich
by “flipping” residential real estate—then your dopamine
neurons will bombard the rest of your brain with a jolt of
motivation. “This kind of positive reinforcement creates a
special kind of attention dedicated to rewards,” says Schultz.
“Rewards are what keep you coming back for more.”
The release of dopamine after an unexpected reward
makes us willing to take risks in the first place. After all,
taking chances is scary; if winning big on long shots didn’t
feel good, we would never be willing to gamble on anything
but the safest (and least rewarding) bets. Without the rush
of dopamine, explains Montague, our early ancestors might
have starved to death cowering in caves, and we modern
investors would keep all our money under the mattress.
3. If a reward you expected fails to materialize, then dopamine
dries up. When you spot the signal that a reward may
be coming, your dopamine neurons will activate—but if you
then miss out on the gain, they will instantly cease firing. And
that will deprive your brain of its expected shot of dopamine.
Instead of a fundamental “I-got-it” response, your brain will
experience a wrenching swing into a motivational vacuum.
It’s as if someone yanked the needle away from an addict just
as he was about to give himself his regular fix.
Why advertise in Journal of Indexes?
journal of indexes print subscriptions online at www.journalofindexes.com/subscriptions
Index Publications LLC, 419 Lafayette Street, New York, NY 10003 • Advertising and Reprints Inquiries: 626.706.7050
www.journalofindexes.com July/August 2008
15