HPS203/773: The Human Mind - Laboratory Report on the Stroop Effect

This laboratory report explores the Stroop effect, a phenomenon demonstrating cognitive interference. The report begins with an introduction to the Stroop effect, explaining how it reveals the brain's automatic processing of information, where individuals respond to the color of a word rather than its meaning. The report then details two experiments: the first examines the effect of interfering word stimuli on color naming, while the second investigates the impact of suggestion on the Stroop effect. The report includes a discussion of the methods, results, and implications of each study, including the findings of research by Raz et al. (2006) on the effects of suggestion, and Bargh, Chen, and Burrows (2006) on the effects of priming on social behavior, as well as a university experiment involving dyslexia priming. The report concludes by highlighting how different levels of priming can affect the Stroop effect and its implications in cognitive psychology.

Running head: LABORATORY REPORT
LABORATORY REPORT
Name of the Student
Name of the University
Author note

1LABORTORY REPORT
Introduction
The Stroop effect is a phenomenon where individuals are asked to respond to the words
that are presented in different coloured inks. This is a process to understand the automatic
processing of the brain. A colour is written on a paper but with a different coloured ink and the
participants have to respond to the colour of the print and not the name of the colour. The Stroop
effect provides evidence that the brain gives more importance to automaticity in reading (Stroop,
1935). It is important to study Stroop effect because it helps understand the brain processes
involved in automatic processing and why does the brain give emphasis to the physical attributes
of the stimuli before understanding the meaning behind it. Several experiments have been done
to understand the processes and some of them are listed below.
The Stroop Effect
The Stroop effect demonstrates cognitive interference as a result of incongruity in the
stimuli that causes the reaction time to get delayed. Visual processing is an important
determinant of interaction with the world. The brain processes not only the physical attributes of
the stimuli; it comprehends the meaning behind it too.
Methods
Experiment 2 was conducted to determine the effect of interfering word stimuli upon
naming colours. A hundred students were taken as subjects and each subject was asked to read a
whole sheet. The sheet contained name of the colours and they had to read out the name of the
print of the colour and not the colour itself. For example, if the colour written was “blue” but the
colour of the print was red, then the student had to respond with red. The time was recorded
along with the errors. In order to balance out the practice and fatigue effect, some students read

2LABORTORY REPORT
out in the order of “NC, NCWd, NCWd, NC” where “NC” meant Name of the Colour and
NCWd meant name of the colour of the word print. The other half number of students read in the
order of “NCWd, NC, NC, NCWd”.
Results and implications
When the results of these two groups were compared, it showed that the mean of the
responses increased from 63.3 seconds to 110.3 seconds (Stroop, 1935). The S.D. or standard
deviation was almost similar. The increase in the mean implied the strength of interference due
to the practice of saying words instead of the colours.
Research report by Amir Raz and colleagues
Aim
The main aim of the experiment was to determine the effects of suggestion on Stroop
interference in those individuals who were highly suggestible. The independent variable was the
suggestion that was to be given to the participants and the dependent variable was interference in
the Stroop effect.
Methods
Each participant had to engage in this task twice. Once they were given suggestion
through inducing hypnosis and the second time they had to carry out the task without inducing
hypnosis. The design of the experiment was a mixed design that considered hypnosis as a
between-subjects factor. Congruency as well as suggestion were considered as within-subjects
factors.
Results and implications

3LABORTORY REPORT
The results indicated that the effect was little when suggestion was given to the
participants than without suggestion (Raz et al., 2006). When the task was provided without
suggestion to the participants first, “The Stroop effect” was smaller. In conclusion, the results
showed that suggestion reduced the effect in individuals who were highly suggestible and also
that it did not depend upon hypnosis on the individuals.
Research by John Bargh and colleagues
Aim
The aim of this paper was to analyse the behavioral consequences in individuals as a
result of trait construct priming. The number of seconds that the participant waited to interrupt
the experiment was the dependent variable and the independent variable was the three conditions
of priming - “rude, polite and neutral”.
Methods
The researchers used 34 participants from “New York University”. The priming
manipulation was given as a language ability test called the “Scrambled Sentence Test”. Three
priming constructs were used that were as follows: “rude”, “polite” and the third was a neutral
priming trait. The hypothesis of the researchers was that the participants who were in the “rude
prime condition” would likely interrupt faster than those who were in neutral condition. The
participants who were in the “polite prime condition” would likely take more time to interrupt
than the participants in neutral condition would. Whenever any participant said anything to
interrupt the experiment, the confederate in the experiment stopped the watch and recorded the
time.
Results and implications

4LABORTORY REPORT
The participants who were in rude priming condition were seen to interrupt faster with a
mean of 326 seconds than those in the neutral condition with a mean of 519 seconds and in polite
conditions with a mean of 558 seconds. The t-tests showed that mean of “rude” prime condition
was significantly shorter than the means of the other two conditions (Bargh, Chen and Burrows,
2006). The hypothesis was proved to be true that stated that behaviour of social interaction could
be primed. However, time taken in interruption distribution varied significantly from normality.
University experiment
The study examined the effects of Stroop effect through dyslexia priming. The
experiment included responding to the colour of the print of the letters and then a dyslexia
priming was introduced where a passage had to be answered on a person facing difficulties due
to dyslexia and then another round of the Stroop effect was introduced. The independent variable
was dyslexia priming and dependent variable was the response to the Stroop effect. The rationale
of the current study is to understand how various levels of priming can affect Stroop effect in an
individual, whether dyslexia priming can increase or decrease the time taken by individuals.
When people are given dyslexia priming, it reduces however, does not eliminate the normal
magnitude of the interference in such effects. This is because of the control of processes that are
included in selection of responses.