Stroop Effect
-named after J. Ridley Stroop
-described in the 1930s
-referred to these tests as RCNs or Reading Color Names –where participants
were required to repeat the written word with differing colored fonts
-and NCWs or Naming Colored Words – where participants were asked to
verbally identify the color of each printed color name
-Stroop noticed a large increase on the time take to complete the NCW portion
of the test
-doesn’t improve with practice!
-theorized that there was interference caused by the automatization of reading
-where the mind automatically determines the semantic meaning of
the word and overrides its first impression which is the identification
of the color
-in other words – once we learn to read – this takes priority over
identifying something more simple as color (i.e. RCN>NCW)
-the Stroop test measures this interference
-used to investigate other psychologic disorders as ADHD, schizophrenia and
anorexia – areas that involve the Anterior Cingulate Gyrus (an area of the brain
involved in attention, motivation, error detection)
Stroop test #1 (NCW)
• Read the color of the word
• Piece of cake right??
Stroop test #2 (RCN)
• Read the word and time yourself – NOT the
color
• Still easy right?
Stroop test #3
• Now….. Read the color of the word and time
yourself – NOT the word
• Not so easy, eh??
The results
• Reading a color is simple right?
• Only when it matches the word!
• When the color and word match its easy. That’s RCN
– But you are actually reading the word and NOT
the color – RCN>NCW
• But when the RCN and NCW are different – you slow down!!!
Number Stroop test
• Read the word in the box
Set #1
cat
cat
cat
flag
flag
flag
cat
cat
pen
pen
car
door
car
door
door
door
door
hand
hand
door
door
door
ball
ball
pen
pen
pen
pen
car
car
ball
ball
ball
ball
hand
hand
flag
flag
flag
flag
flag
ball
hand
hand
hand
cat
pen
pen
pen
• Count the number of words in the box
• Which task was easier/faster??
cat
cat
cat
flag
flag
flag
cat
cat
pen
pen
car
door
car
door
door
door
door
hand
hand
door
door
door
ball
ball
pen
pen
pen
pen
car
car
ball
ball
ball
ball
hand
hand
flag
flag
flag
flag
flag
ball
hand
hand
hand
cat
pen
pen
pen
• Be honest …… You slowed down didn’t you?
• Words still have priority
• Again…say the words first
• Then count the number of words in the box
three
three
two
two
two
one
one
one
one
one
one
three
two
four
two
two
two
four
four
two
two
two
three
four
four
one
one
one
three
three
two
two
two
two
four
three
three
one
one
one
one
four
four
two
two
two
one
one
one
Directional Stroop
• Name the word in the box
• Give the Direction of the word in the box
– Is it on the top? On the left? Etc…..
• Again – words take precedence?
• Plus – girls are lousy at right/left! 
• Don’t laugh boys – at least girls ask for directions!!
Stroop for kids
• What is the animal? (don’t read the word)
• Aha! But you are still reading the word
• Don’t believe me??
• Read the word
• Now…. Identify the animal again
The Stroop effect and Pain
• Researchers have postulated the Anterior
Cingulate gyrus is also involved in pain
processing
• Your perception of pain can be decreased by
performing the Stroop test
• Don’t believe me?
• Have your partner repeat these tests while
you punch him/her!
• JUST KIDDING!!!!!!