When you first learned to tie your shoelaces, you needed to think carefully through each
step of the process. Now, you probably do not even think about the steps, but simply
initiate a series of movements that proceed without any further influence. When a
behavior or skill no longer requires direct interaction, cognitive psychologists say it is
Many behaviors can become automatized: typing, reading, writing, bicycling, piano
playing, driving, etc. Automatization is interesting because it is an important part of daily
life. We perform a variety of automatized behaviors quickly and effortlessly. In some
cases, people report that they do not consciously know how the behavior is performed,
they just will it to happen and it does happen.
To explore properties of automatized behaviors, cognitive psychologists often put
observers in a situation where an automatized response is in conflict with the desired
behavior. This allows researchers to test the behind-the-scenes properties of
automatized behaviors by noting their influence on more easily measured behaviors.
This demonstration explores a well-known example of this type of influence, the Stroop
Stroop (1935) noted that observers were slower to properly identify the color of ink
when the ink was used to produce color names different from the color of the ink. That
is, observers were slower to identify red ink when it spelled the word blue. This is an
interesting finding because observers are told to not pay any attention to the word
names and simply to report the color of the ink. However, this seems to be a nearly
impossible task, as the name of the word seems to interfere with the observer's ability to
report the color of the ink.
A common explanation for the Stroop effect is that observers (especially college
undergraduates) have automatized the process of reading. Thus, the color names of the
words are always processed very quickly, regardless of the color of the ink. On the
other hand, identifying colors is not a task that observers have to report on very often
and, because it is not automatized, it is slower. The fast and automatic processing of
the color name of the word interferes with the reporting of the ink color.
A window will appear that fills nearly the entire screen, and a smaller window will appear
with abbreviated instructions. Close the instructions window. You can open it again later
from the 'Lab Info.' menu.
Start a trial by pressing the space bar. A fixation dot will appear in the middle of the
window, stare at it. A short time later (less than a second) a word (RED, GREEN, or
BLUE) will appear on the screen, and the word will be displayed in a red, green, or blue
color. Your task is to classify, as quickly as possible, the font color, regardless of the
word name. If the font color is red, press the h key; for green, press the j key; for blue,
press the k key. It may take a bit of practice to remember which key corresponds to
which font color.
After pressing a key to identify the font color, you will receive feedback on whether you
were correct. If you were incorrect, the trial will be repeated later in the experiment. If
you find you are making lots of mistakes, you should slow down or make certain you
understood which key goes with which font color. Press the space bar to start the next
There are at least 45 trials, 30 in which the font colors and word names are different,
and 15 in which the font colors and color names match (e.g., the word RED in red font
color). You can also discard a trial by pressing the t key instead of identifying the font
color. Discarding is appropriate if, after starting a trial, you sneeze, zone out, or are
otherwise distracted. Discarded trials will be repeated later.
At the end of the experiment, the experiment window will close and a new window will
appear that displays your data as a table and a plot (if appropriate) and provides an
explanation of the experiment and results. You can print this information, save it as an
html file, or save it in CogLab format. The latter format can be re-opened with CogLab
on a CD and by your instructor who may want to combine data from students in your