couldn't even begin to write this for you until
I'd made myself a coffee. Some days I drink tea, but
coffee is my normal stimulant of choice, and a cup of that
ol' "creative lighter
fluid" is just what I need to get started on my
After you've drunk a cup
of tea or coffee, the caffeine diffuses around your body, taking less
than 20 minutes to reach every cell, every fluid (yes,
every fluid1) of
which you're made. Pretty soon the neurotransmitter
messenger systems of the brain are affected too. We know for certain
that caffeine's primary route of action is to
increase the influence of the neurotransmitter dopamine, although
exactly how it does this is less clear.2
Upshifting the dopaminergic system is something
caffeine has in common with the less socially acceptable stimulants
cocaine and amphetamine, although it does so in a different
Neurons [Hack #9] use
neurotransmitters to chemically send their signals from one neuron to
the next, across the synapse (the gap between two neurons). There are
many different neurotransmitters, and they tend to be used by neurons
together in systems that cross the brain. The neurons that contain
dopamine, the dopaminergic system, are found in systems dealing with
memory, movement, attention, and motivation. The latter two are what
concern us here.
Via the dopaminergic system, caffeine
stimulates a region of the subcortex (the brain beneath the cerebral
cortex [Hack #8])
called the nucleus accumbens, a part of the
brain known to be heavily involved in feelings of pleasure and
reward. Sex, food, all addictive drugs, and even jokes cause an
increased neural response in this area of the brain. What happens
with addictive drugs is that they chemically hack the
brain's evolved circuitry for finding things
rewarding—the ability to recognize the good things in life and
learn to do more of them.
The jury is still out on whether most caffeine addicts are really
benefiting from their compulsion to regularly consume a brown,
socially acceptable, liquid stimulant. While some killjoys claim that
most addicts are just avoiding the adverse effects of withdrawal, it
is more likely that most people use caffeine more or less optimally
to help them manage their lives. One study even went so far as to say
"regular caffeine usage appears to be beneficial,
with higher users having better mental
it's not just pleasure-seeking,
Coffee is strongly associated with two
things: keeping you awake and helping you do useful mental work. In
fact, it can even be shown to help physical
performance.5 The association with
creative mental work is legendary, although the cognitive mechanisms
by which this works are not clear. As early as 1933, experiments had
shown that a cup of coffee can help you solve chess
problems,6 but the need for experiments
has been considered minimal given the massive anecdotal evidence. As
the mathematician Paul Erdos said, "A mathematician
is a device for turning coffee into theorems."
Academics, designers, programmers, and creative professionals
everywhere will surely empathize.
But this isn't a hack about the addictive effects of
caffeine, or even about the mental stimulation it can provide. This
is about how coffee can work its magic on me without passing my lips.
It's having its effect while it's
still brewing. I need to make a cup to get started, but I
haven't begun drinking it yet.
Just knowing you have a caffeine hit coming tends to perk you up. We
value more than just the chemicals here. To see this in action, find
someone who is a certified caffeine addict. It
doesn't matter if she is into tea or coffee, as long
as she is really into it. I'd
wager that she is also rather particular about how she takes it too.
Does she have a favorite mug? Does she like the milk poured in before
the tea? Is she picky about how the coffee beans should be ground?
Now, find something that doesn't affect the taste of
the drink, but that she always does—it doesn't
really matter what. Stop her from doing it. Give her coffee to her in
a glass. Put the milk in after the tea. Do the opposite of the way
she likes something done.
She'll freak. Or at the very least she
really won't like it.
The more she's into caffeine, the more particular
she'll be about the drink being made and delivered
in just a particular way. Weird, eh? She's addicted
to a complex molecule; the delivery of it into her system, in any
form, is enough to create the positive effects of the drug and remove
any associated withdrawal symptoms. But she insists on the precise
method of delivery. How come?
How It Works
By chemically hacking the reward
circuitry of the brain, caffeine gives us a stark view of a couple of
the basic animal learning mechanisms. These are called
classical conditioning and operant
conditioning and are associated with the scientific school
called behaviorism, which dominated modern
psychology until the 1970s.
You've probably heard of
Pavlov, the Russian scientist whose experiments with dogs established
the basic principles of classical conditioning. This basically says
that, if something happens at the same time as something rewarding,
it comes to be associated with the response to—and can
eventually substitute for—the rewarding stimulus. In this case,
the caffeine is the intrinsically rewarding stimulus (because it
hacks your reward circuitry) and everything else (the smell, the
taste, the cup, the time of day) comes to be associated with the
reward. This is why decaf can actually work wonders (particularly if
your subject doesn't know it is decaf, thanks to the
Placebo Effect [Hack #73]) and
why just making a cup of coffee makes me feel more alert, even
without drinking it. When I used to write essays late at night at
college, just the sound of the kettle reaching the boil would make me
feel more alert. The response (perking up) becomes associated with
the things that normally accompany the actual cause (the
caffeine)-the smell of coffee, the sound of the kettle boiling, and
other major kind of conditioning, operant
conditioning, states that rewards reinforce the actions
that precede them. While this sounds pretty obvious, you can get a
very long way just by looking at the world through the lens of
"What actions are rewarded? Which are
punished?" In the case of our caffeine
experimentation, everything leading up to the consumption of the
caffeine is rewarded. No wonder we develop superstitions about how
the caffeine should be prepared. In fact all drugs are associated
with preparation rituals: from the Japanese tea ceremony, to clinking
glasses of beer, and up to the harder drugs and things like the
shooting rituals of heroin users.
These learning mechanisms are intrinsic
and are found in all complex animals. They are deeply programmed into
our brain and can operate without conscious effort or memory. Decades
of work have explored how the time scales, constraints, and
interactions of these forms of learning combine with different
stimulus and response pairings and different combinations of reward
and punishment. For example, we know that rewards are often better
motivators than punishments, partly because they are more precise;
you can simply reward the behavior you want, whereas with punishment
you tend to punish getting caught, rather than accurately punishing
the behavior you don't want.
This associative form of learning is basic
to human nature, and its effects are widespread. If you reward your
child by giving in after 20 minutes of nagging, is it surprising that
this habit becomes common? If your manager punishes people who make
mistakes, is it any wonder that people at work cover up their errors
rather than admitting them? And if I've drunk a cup
of coffee on a thousand previous occasions just before starting work,
is it any wonder I feel a sense of contentment when sitting down to
write with a steaming mug of the black stuff beside me and feel
distress when I'm deprived of it? It may be
arbitrary which mug I started drinking my coffee in, but now it has
been wired into my brain via the reinforcing effects of caffeine. The
coffee really does taste better when drunk from my favorite mug.
Two thoughts for you: (1) plants probably evolved caffeine as an
insecticide, and (2) caffeine is used in animal artificial
insemination to make sperm swim faster.
Caffeine probably blockades a messenger chemical that competes with
dopamine (adenosine), so this in turn causes an increase in the
effect of dopamine. The "inhibition of
inhibition" pattern is standard for many connections
and chemicals in the brain.
Some indication of the levels of obsession invoked by caffeine can be
seen at http://coffeegeek.com.
Discussed and referenced in Stafford, T. (2003). Psychology in the
coffee shop. The Psychologist, 16(7), 358-359.
Available online from http://www.bps.org.uk.
"Caffeine and Exercise Performance"
Holck, H. (1933). Effect of caffeine upon chess problem solving.
Journal ofComparative Psychology,