Stroop Effect

Stroop Effect

Reduction of the stroop effect

Abstract:

The stroop effect can be reduced through stroop dilution and this is achieved through the use of neutral words. This paper focuses on a study undertaken on a sample where n = 30 and the participants were exposed to three tests, one test included testing time taken to read colour words which had the same colour as the word stated, the second test was to record the time taken to read words colour words that had different colours as the colour word stated and the third and final test was to test the time taken for the individual to read neutral words containing different colours.

The study was undertaken to determine whether there was a reduction in the stroop effect which was to be based on the time taken to accomplish the three tasks, it was found out that indeed the stroop effect reduced ands this was noted due to the reduction in the time taken in

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Stroop Effect

reading the third task.

Introduction:

The stroop effect is viewed as the interference when undertaking a task; this effect was first coined by Ridley Stroop in 1935. his findings were that there was usually a delay when naming a colour name which is written in a different colour, example writing the word RED in colour red would result into much easier to read than if RED is written in blue, this is due to the stroop effect. Some theorists have come up with explanation of this effect and this includes the speed to process theory and the selective attention theory.

According to the speed of process theory the stroop effect is viewed as an interference which occurs because the words are read faster than colour naming, this theory states that words are easily read than the colours and for this reason the effect occurs. The selective attention theory on the hand states that the stroop effect occurs because colour naming requires more attention than when a person is reading the word, therefore because of the ease to read words the effect

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Stroop Effect

occurs.

The importance of the Stroop effect in psychology can be viewed in the ability to manipulate or control the effect which can be used to improve the cognitive abilities of individual and increases the chances of good judgment and decisions in actual world scenarios.

Other scholars such as Cho, Lien, and Proctor (2006) found out that neutral words can reduce the Stroop effect, the use of neutral wards is what is referred to as stroop dilution, However Brown, Roos Gilbert and Carr (1995) reported that the reduction of the Stroop effect does not differ when words or symbols are used. Kahneman and Chajczyk (1983) on the other hand stated that showed that Stroop effect is reduced when the incongruent colour word and neutral words are placed to the side (flanks) of the colour patch. They noted that interference attributed to the Stroop effect required attention and that spreading the attention in more locations causes reduction of the Stroop effect.

Aims:

This paper investigates the ways by which we can reduce the stroop effect, the experiement undertaken entails the recording of time taken to read words in three different tasks, this study on the reduction could be useful in further understanding of the stroop effect and what causes it and whether the theories stated truly reflect the cause of the effect.

Hypothesis:

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Stroop Effect

The average time taken to read neutral words is less than the time taken to read colour words that portray the stroop effect.

Methods:

Participants

A total of 30 respondents were randomly selected and were subjected to the Stroop tests. The profile of the respondent is an important factor in cognitive test since responses varies with age and sex (Trafton, Richard S., Garrison, William T., 1982). However, this study did not consider sex and age as a factor in identifying the respondents.

Design

The experiment was conducted using a questionnaire which involved three tasks that was to be completed by the respondents one after the other, the respondents was to complete one task and record time used and then finish the other tasks recording time used to complete them. The tasks were designed in a way that the first tasks were not to portray the stroop effect, the second task was to portray the stroop effect and the final task was to portray colour dilution.

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Stroop Effect

Materials

Each respondent was given a questionnaire which are a list of colour names printed in different colours, the tasks were to be completed one after the other and the respondents were given a stop watch to help in determining the time used in completing these tasks. The list of test materials used in the test instrument is presented in Appendix 1.

Procedure

The test instruments were presented to respondents who use English as their first language with no problem in naming the colours. A form was filled up by the participants to show their consent in participating in the study. After a thorough explanation of the process the respondent were asked individually to complete the task and record time.

Results:

After the 30 complete questionnaires were collected the data was compiled into a single worksheet to undertake statistical inferences, the data collected is summarised in the table below, and detailed data from the study are available in appendix 2:

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Stroop Effect

task  one

task  two

task  three

respondent

time  in seconds

time  in seconds

time  in seconds

total

28.29

32

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28.03

mean

0.943

1.066666667

0.934333333

sd

0.130625815

0.204439239

0.237656422

variance

0.017063103

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Stroop Effect

0.041795402

0.056480575

mode

0.88

0.99

0.88

median

0.905

1.025

0.935

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Stroop Effect

From the above table the average time for the first task is 0.943, the mean for the second task is 1.0667 and the mean for the final task is 0.93433. The second task shows the stroop effect because more time is required to read the words than in the first task. To check the existence of the stroop effect in our study we will consider the hypothesis test whether the mean in the first task is less than the mean in the second task

Hypothesis:

The stroop effect:

The mean of task one is less than the mean in task two:

Null hypothesis:

H0: x1 = x2

Alternative hypothesis

Ha: x1 < x2

The hypothesis test for this case will be as follows:

X1–X2

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Stroop Effect

Z =  ___________

[(σ12/ n1) + (σ22/ n2)] ½

Then we substitute the formula as follows:

X1 is the mean for task one

X2 is the mean for task two

σ1 is the standard deviation of task one

σ2 is the standard deviation of task two

n is the sample size

0.943 – 1.066666667

Z    =  _________________________________

[ (0.017063103/ 30) + (0.041795402/ 30)] ½

Z = -2.79196

At 99.5% level of test the Z critical value is 3.038

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Stroop Effect

And because our Z critical is less than our Z calculated then we reject the null hypothesis, this means that the two means are not equal and this means that our data portrays the stroop effect.

The next hypothesis test is concerned about how to reduce the stroop effect through the use of neutral words also known as stroop dilution, for this case we are to check whether the mean for task two is greater than the men for task three, from the previous discussion task three involved the use of neutral words, whereas from the previous hypothesis task two portrayed the stroop effect, therefore we state the null hypothesis and the alternative hypothesis:

Null hypothesis:

H0: x2 = x3

Alternative hypothesis

Ha: x2 < x3

The hypothesis test for this case will be as follows:

X1–X2

Z =  ___________

[(σ12/ n1) + (σ22/ n2)] ½

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Stroop Effect

Then we substitute the formula as follows:

X2 is the mean for task two

X3 is the mean for task three

σ2 is the standard deviation of task two

σ3 is the standard deviation of task three

n is the sample size which is equal to 30 in both cases

1.066666667 – 0.934333333

Z =  _________________________________

[(0.041795402/ 30) + (0.056480575/ 30)] ½

Z = 2.312098

At 98% test level the Z critical value is 2.462

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Stroop Effect

And because the Z critical is less than the Z calculated we reject the null hypothesis and accept the alternative hypothesis that states that x2 < x3, for this reason therefore it is clear that in our study the use of neutral words reduced the stroop effect.

Discussion:

In the study above the first and second task was to determine whether there was stroop effect in the tasks assigned, the first task involved a study that involved recording of time used in treading four words which were colour words and the second task involved reading words that were colour words but the font colour was different from the word meaning, the study through the hypothesis test showed that there was an increase in average time used to read out the words in task one, this increase shows the stroop effect.

The third task which involved reading out neutral words whose fonts had different colours was to check whether there was a reduction in the average time used to read out the words. From the hypothesis test it is clear that stroop dilution reduced the effect whereby the average time used to complete task two was greater than the average time used to complete task three.

From this reason therefore we can conclude that the stroop effect is the interference when undertaking a task, it also shows that the effect can be reduced by the use of neutral words also known as stroop dilution.

Conclusion:

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Stroop Effect

The test of the stroop effect shows that there is usually an interference in performing reading tasks especially colour font words, however from this study stroop dilution is a way which the stroop effect can be reduced, this was the main aim of the study to check the validity of the assumption that stroop dilution can reduce the stroop effect, from the hypothesis test it is clear that the mean for completing the final task was less.

The study comprised of 30 respondents who were briefed on the aims of the study and all the respondents completed the tasks successfully and data used for statistical analysis. However there is need to undertake another study which involves a larger or different sample in order to validate the theory. Further studies should also be aimed at determining what causes the stroop effect and other how other methods can be used to reduce the effect.

The first and second task was to determine whether there was stroop effect in the tasks assigned, the hypothesis test of the means obtained in both tasks showed that there was an increase in average time used to read out the words in task one, this increase shows the stroop effect. The third task involved reading out neutral words whose the hypothesis test in this case showed that indeed the stroop effect was reduced due to the reduction in the mean time used to read out complete the task. Therefore stroop effect can be reduced by the use of neutral words also known as stroop dilution.

References

De Young, Robert (2007). Stroop task. Retrieved on September 27, 2007 from http://www.snre

.umich.edu/eplab/demos/st0/stroopdesc.html

Kahneman, D. & Henik, A. (1981). Perceptual organization and attention. In M. Kubovy & J.R. Pomerantz (Eds.), Perceptual Organization (pp. 184-189), Hillsdale, NJ: Lawrence Erlbaum Associates.

MacLeod, C. M. (1991). Half a century of research on the Stroop effect: An integrative review. P

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sychological Bulletin,

109

, 163-203.

Cho YS, Lien MC, Proctor RW. (2006) Related Articles , Links Stroop dilution depends on the nature of the colour carrier but not on its location.

J Exp Psychol Hum Percept

Perform. Aug; 32 (4):826-39.

Roberts MA, Besner D. (2005) Stroop dilution revisited: evidence for domain-specific,

limited-capacity processing.                                                          J Exp Psychol Hum Percept Perform.

Feb;31(1):3-13.

Mitterer H, La Heij W, Van der Heijden AH (2003) Stroop dilution but not word-processing

dilution: evidence for attention capture. Psych ol Res.

Feb;67(1):30-42.

Brown TL, Gore CL, Carr TH. (2002) Visual attention and word recognition in stroop colour

naming: is word recognition "automatic"? J Exp Psychol Gen. Jun ;131(2):220-40.

Brown TL, Roos-Gilbert L, Carr TH. (1995) Automaticity and word perception: evidence from Stroop and Stroop dilution effects. J Exp Psychol Learn Mem Cogn. Nov;21(6):1395-411.

Trafton, RS., Garrison, WT. (1982). Male-Female Differences in Cognitive Abilities in Various Age Group. (ERIC Document No. ED228415) Retrieved September 27, 2007 from ERIC Database

Raz, A., Kirsch, I., Pollard, J., & Nitkin-Kaner, Y. (2006). Suggestion reduces the Stroop Effect. Psychological Science, 17(2)

, 91-95

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Appendices:

Appendix 1:

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Appendix 2:

task  one

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task  two

task  three

respodent

time  in seconds

time  in seconds

time  in seconds

1

0.87

0.84

0.88

2

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0.99

1.02

1.02

3

0.88

0.9

0.87

4

0.88

0.87

0.78

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5

0.77

1.04

0.03

6

1.01

1.05

1.04

7

1.04

1.03

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1.18

8

1.12

1.14

0.89

9

1.23

0.89

0.94

10

0.87

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0.99

0.78

11

0.9

0.87

0.88

12

0.88

0.98

0.94

13

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0.78

0.9

1.01

14

1.01

1.03

0.77

15

1.03

1.08

0.88

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16

0.89

0.99

0.94

17

0.77

1.23

0.89

18

0.78

0.84

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Stroop Effect

1.06

19

0.91

0.99

1.67

20

0.94

0.85

1.04

21

0.9

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1.23

1.08

22

1.04

1.2

0.93

23

1.3

1.45

0.88

24

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1.08

1.55

0.93

25

1.05

1.01

1.07

26

0.93

1.61

1.01

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27

0.94

1.05

0.99

28

0.88

1.14

0.87

29

0.85

1.34

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0.98

30

0.77

0.89

0.8

total

28.29

32

28.03

mean

0.943

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1.066666667

0.934333333

sd

0.130625815

0.204439239

0.237656422

variance

0.017063103

0.041795402

0.056480575

mode

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0.88

0.99

0.88

median

0.905

1.025

0.935

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