The Stroop Effect

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Themain focus of this experiment is to determine the Stroop effect andthe differences in reaction time of both the congruent andincongruent experimental conditions. 22 participants are involved.Repeated design measurements were then used for these two conditions.The participants were then required to observe the inked words andname the color of the inks used, and at the same time, ignore theactual words. Based on the experiment, the results will show thereaction time to be faster in congruent conditions and with fewererrors made compared to incongruent conditions. The significancelevels were noted to be p&lt0.001, which meant that the probabilityresults were as a result of chance being less than 1 percent. It alsoproves that both the hypotheses were correct, and thus back up theoriginal Stroop effect investigation. The paper also identifieslimitations of the experiment and future research studies targeted atimproving future experimental studies.


The“attention” process demands cognitive ability of a person to payattention on particular stimuli selectively, especially in theenvironment while ignoring others selectively. However, individual’sattention is diverted from a different stimulus by interference.Interference, according to Marmurek (2003), became more influentialin both the neutral and cognitive components of selective attention,and thus forms the basis for research study before to Stroop.Originally, the Stroop effect was named after an Americanpsychologist, John Ridley Stroop following an article published in1936. The test shows and demonstrates reaction time differences ofnaming colors, reading names, and placing names on colors of wordsprinted in varied ink type. The Stroop effect also targets to measurethe level of cognitive ability, both learning and memory, and focuson attention.

Havingbeen coined by James McKeen Cattell, Stroop’s research found outthat responding to colors and objects took longer time to read aloudthan it was to words. The involvement between ideas and words occurfrequently that it turn out to be an automated process. Unlike usingcolors and pictures, one intentional effort had to be carried out.Here, the Stroop effect was applied for purposes of discrediting thetheory of automatic and controlled processing (Lien &amp Proctor,2002). Since the Stroop’s experiment, there are a lot of variationsmade to test and analyze the difference in phenomena. For instance,sorting out and matching different versions of color word tasks,Stroop color word-test, and picture-word task.

TheStroop effect is an example of cognitive psychology experiment. Forexample, if a person tries to identify the name of a color which theworld is printed on it, longer time is taken especially when theactual word is a color word, but of different color. Therefore, ittakes more time to identify a green color if at all the green word onprint is actually “red.” Mama (2010) noted that the most commonreasoning for such an effect handles what is known as “responsecompetition.” Responding to both the word and color are formedhowever, we can only make a single response at one particular time.Responding to a single word may be a little faster than responding tothe color and thus blocks the ability to name the color.


Design:This experiment uses repeated design measures. Here, the samenumber of participants is used for each particular condition, and inthis regard, congruent and incongruent. The design allows responsesfrom a participant for the specified congruent condition to becompared directly to their response about incongruent condition. Inthis experiment, a specified word is placed at the center of thescreen. Often, a color word like “green,” but is written in red,for example, and thus might appear like a green color. Theparticipant will be asked to identify the color, which in most caseswill be red. Following the participant’s response, the next one isplace. Meanwhile, the computer is able to record the response made bythe person to ascertain the accuracy and the response reaction time.

Of importance to note about such experiment is based on the fact thatthe experiment will be able to add certain value about a variable andrecords what happens. The participants involve 22 psychology studentsfrom Royal College University aged between 18 and 21. A computer wasto create two stimuli and also to collect responses from theparticipants. The program involved the participants responding to thecolor of the ink used on words while ignoring the word itself. Thewords were placed in the middle of the screen for close to 800ms.

Procedure: The experiment was done in two parts. In part oneparticipants were required to follow set instructions. The need toadhere to instructions allowed more information about theparticipants to recorded for rigorous analysis to be done about toconsider biasness. In the second part, the participants took part in9 trials, which include four congruent analyses and five incongruentanalyses. The participants were then required to focus on the fixatedpoint (+) that was followed by specific words presented in variedcolored ink, and were then required to identify the ink color.

Additionally, specific keys were applied in identifying the colorschosen, which include 1 green, 2 red, 3 blue, and 4, yellow. Intotal, the participants were asked to perform 200 trials for close tofive minutes. Every condition comprised of 100 trials for 25 trialseach color. The responses recorded from every participant for eachspecific condition were then created into a database. In a basicexperiment, 20 words are involved, and both were congruent (color ofthe word match and color word) and the other were incongruent (wordcolor do not match). The two conditions were randomly selected by theprogrammed computer and the condition was then identified before thecommencement of the experiment. .

Inferentials: From the above calculations, the preferredanalysis was a t-test, which allows us to put into comparison theresults in reliability terms as the t-value that was obtained isattached to a specific set value for the degree of experimentalfreedom. The t-value calculated at the set confidence value ofp=&lt0.001 was less than the predicted value for the actual p value.Therefore, this allowed the rejection of null hypothesis whileaccepting the alternative results, which was said to be approximately99% of the congruent value of independent variable.

The use of quantitative of this analysis confirms involvement ofregional subsets to the fear-circuitry implicated on the disorder.Meta-analysis procedure is run on a patient to examine neuralactivity within and across the provocation and emotional-cognitivetasks. Meta-analysis also involves variability in the naming ofmedial prefrontal conventions of cortex regions, in which activatedregions are then listed on the table with both their specificstructural names. The appropriateness of this design is that it isgenerally interactive, inductive, and iterative.

A variable is defined to be any factor, condition, or trait, whichexists in different types or amounts. Any variable that is notintentionally studied is referred to an extraneous variable, whichaims at threatening a researcher’s internal validity (Stroop,1992). Where a research draws on a quantitative design, more so theexperimental designs, researchers often attempt to control it so thatthey do not turn out to be confounding variables. Participants,therefore, often try to control these extraneous variables in anumber of ways.

First,the participants identify specific variables about words and colorthat are more likely to influence dependent variables. To do this,the researcher is required use his or her common sense, pastexperience, and logical reasoning. It is obvious a noisy room cancause a distraction as opposed to a silent room. The researcher’suse of a silent room means that stopping an extraneous variablenoise, from turning into a confounding variable. Secondly, once anextraneous variable has been identified, it can be controlled throughmatching values or holing the variable constant across treatmentcondition (Van der Elst et al., 2006). This is done by establishing astandardized condition, procedure, or environment to ensure allvariables are held constant in the same condition.

Finally,values across treatment conditions should be matched in order toavoid the variables varying across different treatment conditions.For example, participants are often assigned in order to ensure theaverage age turn out the same for all the differing treatmentconditions. Failure to control extraneous variables would turn intoconfounding variables, which means a conclusion arrived at in anexperiment is not correct, thus is important for the researchers tocontrol the extraneous variables.

Proposal: Experimental design is about how the chosenparticipants are placed specifically in different conditions in anexperiment. The most common way in psychology to design an experimentis to place the participants into two separate groups, the control,and experimental groups, followed by an introduction of a change tospecifically the experimental and not the control (Van der Elst etal., 2006). Building on the availed data developed in the previousmodule, one research question is identified as part of the proposalfor an experimental design evaluation. This includes:

For purposes of studying the question, the proposal identifies oneexperimental design method, which is the between-subject designmethod. According to Evans &amp Rooney (2008), the between-subjectdesign refers to an experiment with two or more subjects testedsimultaneously for a different reason from other. This design will beused to evaluate the adolescent males, from the previous module,within the area of study. The two subjects to be evaluated are theadolescent males with behavior disorders and the ones to be helpedthrough family therapy.

As a means of studying the question above, the design method –between-subject – will be justified by the manner in which it willfocus on two subjects simultaneously. For instance, the question isabout a practice effect elicited by a program or intervention, whichwill be used to understand the development or health outcome ofindividuals after an experimental study (Stroop, 1992). Theexperimental design is a justification of the question considering itfocuses on performance change or outcome as a result of repeatedtesting. The design method handles the tests and evaluationrepeatedly within multiple levels in each subject, thus increasingits performance and responsiveness.

The experiment will be conducted by applying different experimentalmethods such as sampling, procedures, measurements, and assignmentstrategies. Sampling, for instance, is the process choosing unitsbased on populations of interests (MacLeod, 1991). The method will beused to conduct the experiment through observation measures bylooking at the observable subjects considered as the independentobjects. Sampling means that the results obtained from thestatistical and probability theory will be employed to direct theexperimental practice in the medical research for the adolescentmales with conduct disorders.

The measurement procedure is a design method with a certain variablebut of unknown value. What the method does is that it defines aprocess of measurement. The task to determine a medical research, forexample, is that it concludes a value of measurement based on theobserved randomness of the subject to determine a true value of theparticipants. Additionally, the method focuses on evaluating theintervention of finding a solution to the disorder. It is specifiedby the level of the deterministic variable, according to Schupak(2008).

Assignment strategy is a method that focuses on making some choicesto promote teach (MacLeod, 1991). The method decides on the kind ofcurriculum, objective, and goals, and research methods. The methoddecides on the whether to use instructional strategies that wouldfocus on the qualities of effective determination of the experiment.The experiment will then be determined based on the overall resultsof the individuals` behaviors, conduct disorders, and healthoutcomes.


Theexperiment conducted exhibited Stroop effect. Three experimental setconditions were identified, and each having a uniquely differentstimuli set. For each set of stimuli, each participant was presentedwith in randomness. First, the control experiment involved a “patch.”Here, the condition involved a color block displayed on a clearsurface (screen), and the participants were then asked to type thename of the color corresponding on the patch. Secondly, the setcontrol condition was regarded as the “name,” whereby the namesfor all the four colors appeared in a congruous manner, and again,the participants are asked to identify the color.

The third one is the mismatched condition, and in this case, all thefour colors were then displayed. However, in this condition, thecolors appeared in a color type that was incongruous, for instance,the word red in blue type. Again, all the participants were asked toidentify the color that was seen. Based on the hypothesis prior tothe experiment, there were to be more errors accompanied by slowerresponse time taken in the mismatched condition different from thetwo prior conditions. In such situations, MacLeod &amp MacDonald(2000) noted that this effect occur due to the divided attention inbetween automatic reading of colors and naming the colors.

Fig: 1 the experiment’s test subjects

We conducted a paired samples T-test for the congruent words (mean +-standard deviation 14 +- 4) and incongruent words (mean +- standarddeviation 24 +- 5.76), (t (21) = -7.16 p&lt.05) a significantdifference was found.


Assend from the diagram above, the results recorded show that the timetake for the completion of the reaction for the entire congruentcondition was faster compared to the time taken in incongruentcondition. After conducting calculations to determine the standarddeviation “error,” it was noted that the incongruent conditionhad a higher “error” values compared to that of the congruentcondition.

Fig:2 the Experimental Condition

Fromthe results, it is evident that both the hypotheses are a prove ofthe Stroop effect, whereby all the 22 participants that undergo theassessment were noted to have significant lower times for reactionwhen naming the ink color compared to that of incongruent condition.Again, the results were evidence that the interference does not takeplace through automatic processing (Mama, 2010). The study alsoproves Stroop effect since it was noted that if the color word wasjotted with the same color, then the time take in stating this by allthe participants involved was noted to be notably faster compared toanother colored ink used.

Therefore, it allowed the success of the research to be carried outin regard to the response in stimuli. This is because the laterresearch indicated that less interference was present when there wasa similarity in stimuli. For example, the “blueberry” wordindicated is associated with the blue color, and thus it would haveless interference than another in another color, for example, theword green.

Limitationsand Future Experimental Research

Limitations:The main limitation was the biasness exhibited from the sample.The participants used were all university students studyingpsychology, and therefore, cannot be generalized and fused as part ofthe society reflection. It is therefore important to note that theresults acquired from the experiment are unreliable. For once, it canbe heavily scrutinized and criticized based on the biasness of genderinvolved since there were only 7 males compared to 15 femaleparticipants (Marmurek, 2003). As shown in the above figure (fig.1),this would have a confounding impact on the results. This is becausethe male participants exuded faster reaction time than their femalecounterparts. Therefore, the limitations can be wired on generalizingthe findings as unequal.

Further experimental research: Improvements are needed forthe improvement of results validity. Here, focusing on a largersample size for the experiment would ensure this experiment becomemore reliable and be in a better position to generalize the entirefindings (Lien &amp Proctor, 2002). For purposes of improving thisaspect, a wider range of age would be more important and increasingthe essence of validity, which is an effect based on attention. Here,it could be applied in further research into participants’ minds.Furthermore, diverse gender would be more beneficial in increasingvalidity level throughout psychology level (Jacobson, 2005). Todevelop the entire investigation, the interference can be measuredwell as part of the reactionary time. The higher results producedindicated high accuracy levels with immense validity standards.However, it will require the external environment be adapted well,and thus eliminate all extraneous variables, which can alter theentire results.


Coinedby James McKeen Cattell, the Stroop effect identifies the use ofcolors and objects, which takes time to focus on words and colors.The involvement between ideas and words occur frequently that it turnout to be an automated process. Unlike using colors and pictures, oneintentional effort had to be carried out. Here, the Stroop effect wasapplied for purposes of discrediting the theory of automatic andcontrolled processing. Since the Stroop’s experiment, there are alot of variations made to test and analyze the difference inphenomena. For instance, sorting out and matching different versionsof color word tasks, Stroop color word-test, and picture-word task.

The paper is an experimental research about the Stroop effect. Fromthe experiment conducted, the study also proves Stroop effect sinceit was noted that if the color word was jotted with the same color,then the time take in stating this by all the participants involvedwas noted to be notably faster compared to another colored ink used.Additionally, the results led to discussion showed that the laterresearch indicated less interference was present when there was asimilarity in stimuli. For example, the “blueberry” wordindicated is associated with the blue color, and thus it would haveless interference than another in another color, for example, theword green.


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