The Massachusetts Institute of Technology (MIT) is
known for its advances in the field of computer science, but
researchers at MIT are doing a lot more than building robots and
improving cryptography. They’re also studying the human brain.
In fact, the best place to go if you want to learn how
the brain remembers patterns is the McGovern Institute for Brain
Research at MIT. In 2005, researchers at the institute published a
study that revealed the complex nature of how the brain creates habits.
As with many experiments in cognitive science, this one involved rats
in a maze.
What made this experiment unique was that the rats had sensors
surgically placed deep within their brains (almost at the center).
The procedure used a T-shaped
maze with chocolate on the left side of the crossbar, as shown in the
following figure. The rats were placed at the bottom behind a
partition. The experiment began with an audible click, which was followed by the raising of the partition.
Figure 1. T-shaped maze from the MIT experiment
Once the partition was up, the rats could smell the
chocolate and their brains worked ferociously as they moved through the
maze looking for it. The rats were sniffing the air, looking at the
walls, and generally studying this new environment. When they reached
the top of the maze, some rats would turn left and others would turn
right, but eventually they all found the chocolate.
The same rats repeated the procedure hundreds of
times. After a while the sensors started to detect a change in those
tiny little brains. The rats developed a habit.
When the rats were initially placed behind the partition, their brain activity was normal. But as soon as the click
was played, the rats that were already familiar with the experiment had
a sharp decrease in overall brain activity. As they followed the maze
directly to the chocolate (always turning left now), their brains
seemed to be fairly idle—except for one part, deep within the center of
the brain, called the basal ganglia. This is an area of the brain that
scientists originally thought was related only to movement and
so-called muscle memory.
When the experiment was new to the rats, their entire
brains worked to process the environment. After repeating the procedure
dozens of times, the rats stored this routine in the basal ganglia and
thus reduced the amount of work the brain had to do the next time it
went through the maze.
In some ways, the rats’ brains were
functioning like a computer’s CPU, which might store the result of some
repeated computation in its cache. The cache mechanism saves clock
cycles, just as the basal ganglia reduces brain activity.
The MIT experiment shed a great deal of light on the
structure of the brain, but it also revealed something new about the
structure of habits. For the rats to make this activity a habit, it
needed to follow a certain format. It’s now accepted among
psychologists that every habit has at least these three components:
The cue for the rats was the click
sound. It signaled their brains to fetch the routine from the basal
ganglia. The routine was the path through the maze that led to the
chocolate on the left. The chocolate, of course, was the reward.
The science behind these elements is new, but
advertising agencies have known about them for a century. McDonald’s
uses its golden arches as a cue, the drive-thru for routine, and a big
greasy hamburger as a reward. Other examples include toothpaste, air
fresheners, and soft drinks, which all achieved marketing success
because these three elements created habits in consumers.
That’s not to say habits are a bad thing. There are
good habits and bad habits, just like anything else. Imagine a Vim user
thinking through the details of every command while editing a shell
script. The absence of habits would make programming tasks a lot harder
and we would need a lot more coffee to do our jobs. But for most
programmers, bad habits go beyond the keyboard. Sometimes, they extend
to food and exercise.