Andy Campbell10/10/13AP PsychPeriod 1

The Significance of the Stroop Effect

Our group will be exploring the Stroop effect and how it can affect reading

comprehension. The Stroop Effect, named after John Ridley Stroop, is a demonstration

of the reaction time of a task and is often used to show the difference between

automatic processing and conscious visual control.  It was first published in 1935 along

with the results of an experiment in which participants had to identify the text color of the

name of a color. The results showed that most people had no trouble identifying the

color of words not relating to color, but difficulty identifying the color of the name of a

color (MacLeod 1-3).

When we look at the words in the test, we process the color and meaning of each

word. If both color and meaning are the same, we can respond rapidly to with the

correct answer. However, if there is a conflict between color and meaning, then the

stimuli are not compatible; we must make a decision and pay more attention to one

stimulus than the other one. Since human experience has taught us to value the

meaning of words more than the color they are written in, we naturally want to say the

meaning of the word instead of its color. When we are told to do the opposite of what

seems natural, we must consciously alter our answers. This leads to a much slower

reaction time. As this is a process one is usually unfamiliar with, it can be difficult. 

The interference provides scientists with a measurable means to investigate how

the brain works. By manipulating the stimuli used for the test in various ways, you can

find out what types of thinking tasks interfere with other thinking tasks. Since seeing a

word, and putting the color you see into words, uses the same part of the brain the two

processes can interfere with each other. (Olson, "What Conflicting Mental Tasks Reveal

About Thinking.")

To explain why this occurs, there are a few well-supported theories. According to

the Rochester institute of Technology, one general finding is that the Stroop effect is

very robust. For example, the Stroop effect extends to color-related words like sky or

strawberry, though not as much. It is resistant to practice. The difficulty of removing the

interference effect of the Stroop task has led some researchers to claim that the brain

has evolved to recognize words without effort. This explanation is called the "automatic

word recognition hypothesis" and it is widely accepted. According to this theory, reading

is an automatic process, which cannot be switched off. So, people see the meaning of

words without much effort. On the other hand, naming colors is not automatic. It

requires more effort than reading, thus creating interference in the Stroop task.

Another theory, the "Speed of Processing" hypothesis, suggests that word

processing is much faster than color processing. Thus, in a situation of conflicting

stimuli between words and colors, when the task is to report the color, the word

information arrives at the decision process stage earlier than the color information and

results in processing confusion. On the other hand, when the task is to report the word,

because the color information lags behind the word information, a decision can be made

before the conflicting color information arrives. This theory is also widely-accepted,

though not as much as the first. The main question is whether the Stroop effect is

caused because of differences in speed of stimuli arriving in the brain, or because

evolution has taught humans to analyze the meaning of a word without consciousness.

Bibliography

"Background on the Stroop Effect." College of Liberal Arts. Rochester Institute of

Technology, n.d. Web. 10 Oct. 2013.

<http://www.rit.edu/cla/gssp400/sbackground.html>.

MacLeod, Colin M. "Half a Century of Research on the Stroop Effect: An Integrative

Review." Graz University. KARL-FRANZENS, n.d. Web. 10 Oct. 2013.

<http://www.uni-graz.at/dips/freudenthaler/unt/Stroop_MacLeod.pdf>.

Olson, Andrew, Ph.d. "What Conflicting Mental Tasks Reveal About Thinking." Science

Buddies. Rockspace Publishing, n.d. Web. 10 Oct. 2013.

<http://www.sciencebuddies.org/science-fair-projects/project_ideas/

HumBeh_p027.shtml#background>.