Introduction
The Stroop test is designed to diagnose the cognitive style of flexibility and rigidity of cognitive control. This cognitive style characterizes the degree of subjective difficulty in changing ways of processing information in a situation of cognitive conflict (Houdé, 2019). Rigid control indicates difficulties in the transition from verbal to sensory-perceptual functions due to the low degree of their automation. In contrast, flexible control indicates the relative ease of such a transition. The Stroop test is widely used in cognitive psychology precisely to reveal the degree of automation of transition from verbal to sensory-perceptual functions.
In its classic version, the test includes three stimulus cards. They include a map of words printed in black ink, a map of colors, and a map of words printed in a font mismatched with the meanings of the colors (Taylor & Workman, 2021). Five colors and words were used: red, blue, green, brown, and purple. The words and colors on the white cards were represented as a matrix consisting of ten rows and ten columns. Each of the five colors occurred twice in each row and column, but they were not repeated in a row and did not form any regular sequences. Words with mismatched meanings were printed the same number of times in each of the other four colors. For example, the word “red” was printed the same number of times in blue, green, brown, and purple. According to this stimulus material, the subjects were offered the following tasks. The first is reading the names of the colors printed in black type and naming the colors.
Another option is to read color names where the color of the font is different from the meaning of the word. Instruction to the test person is to call aloud the colors of the font or to read the words on the map line by line from left to right quickly and without error. If an error occurs, the test person must correct it independently. The average time for the group of examinees to play aloud all the stimuli on the map is an indicator of the effectiveness of the task. The rigidity or flexibility of the control index is calculated as the difference in time to complete the third (colored words) and the second (color) card. The greater this difference is, the greater the interference effect and, accordingly, the more pronounced the rigidity of cognitive control (Spieler & Schumacher, 2019). Interference, in this case, is the result of a conflict of verbal and sensory-perceptual functions. The test subject must ignore the meaning of the word and name the color he or she sees.
Low interference indicates the ability to inhibit inherently more vital verbal functions for the sake of color perception. High indicates that the test subject has difficulty releasing himself from the influence of the word’s meaning when it does not correspond to the visual impression. The Stroop method allows for an additional index of verbality (Scharfen et al., 2018). This is defined as the ratio of time spent on the second (color) card to the first (words) card. High values of this parameter indicate a prevalence of the verbal method of information processing, and low values indicate a prevalence of the sensory-perceptual. The interference index is interpreted as a measure of the automation of cognitive functions, that is, the degree of their independent functioning. Thus, one pole of this cognitive style characterizes flexible control and strong automation of cognitive functions, and the other pole characterizes rigid control and weak automation of cognitive functions.
Various modifications of the Stroop test are also used in cognitive psychology. For example, American psychologist Louis Thurstone used only four colors, black background cards, and circles instead of squares on color cards to study perception (Roy et al., 2018). Arthur Jensen proposed another variation; he arranged the stimuli on the cards in random order, avoiding repetition. Despite the different modifications, they all had the same goal: to determine the flexibility of cognitive thinking (Chen et al., 2019). Among other things, the Stroop test indicates an individual’s ability to focus and concentrate at that moment. High levels of stress, the presence of any unresolved problems, and pronounced sleepiness interfere with the test. However, if a person does not have such indicators and still has difficulty taking the test, he or she should pay attention to concentration problems.
Strength and Limitations of the Stroop Test
Like any other psychological test, the Stroop task has its strengths and limitations. The primary strength of the Stroop test is its wide range of possibilities and applications. It can be considered one of the few universal psychological tests aimed at dashing a person’s cognitive functions. A second advantage of using this technique is its high adaptability. The Stroop test can be adapted to measure attention, emotional tone, and other health-related mental abilities (Erdodi et al., 2018). It can be easily converted to automated platforms, which guarantees more accurate test results than those that require manual transcription. For example, other cognitive flexibility tests, such as the Montreal Cognitive Assessment, require psychological expertise for manual decoding. On the other hand, the Stroop test can even be interpreted by the test taker, knowing the designation of the indicators.
The possibility of incorrect manual decoding of the Stroop test is also leveled out by the fact that the test itself is not difficult to interpret. In the context of adaptability, it is also important to mention that the Stroop test can easily be translated into other languages, which means it is equally effective across different cultural and ethnic groups (Vitevitch, 2019). This fact also speaks in favor of its universality. Thus, the strengths of the test are its versatility and adaptability. It is easy to decipher and does not require much training from the test taker and the tester. It can be performed at any time of the day, regardless of the test taker’s sleep regime. That is why the Stroop test is very convenient for a relatively quick and accurate determination of a person’s cognitive flexibility. However, this psychological test also has certain limitations. Despite the versatility of this technique, the Stroop effect may not work correctly, even when applied with proper planning and using the right platform.
First of all, the Stroop test requires a certain degree of literacy on the part of the test taker. This criterion implies that the person taking the test differentiates between words. One of the most critical components of the Stroop effect is the subject’s concentration on the text. When he sees that the meaning of a word does not match its color, such as the word “red” written in green, there is cognitive dissonance (Boeck & Minjeong, 2019). The rate at which the subject overcomes cognitive dissonance is the primary variable measured by the test. There is no cognitive dissonance if a person cannot read the words, and the test is ineffective. For this reason, the test is not suitable for infants and preschool children.
Special tests are developed for these population groups, considering the low level of literacy of test takers. In addition, depending on the study design, it is worth considering gender bias. According to research, women tend to do better on verbal and fine-motor tasks, and men have greater spatial abilities (Daniel & Kapoula, 2019). Thus, for a more correct understanding of the research results, it is necessary to consider the gender variable. Another test weakness is its dependence on the test taker’s honesty. For example, some people can temporarily defocus their vision. Thus, they see fuzzy outlines instead of words, which prevents them from concentrating on their meaning. Consequently, the subject can easily name the colors of words because they see blurry outlines instead.
Conclusion
To summarize, the Stroop test is one of the universal methods of testing a person’s cognitive abilities. Its main advantages are ease of interpretation and translation into other languages. In addition, the test is also relatively easy to perform and requires no special training. A disadvantage of this technique is the necessary degree of literacy, without which the test taker cannot correctly pass the test. Because of this, the Stroop task is not suitable for infants and preschool children. Nevertheless, the Stroop method is a fast and effective cognitive test for adults.
References
Boeck, P., & Minjeong, J. (2019, February 6). An overview of models for response times and processes in cognitive tests. Frontiers in Psychology. Web.
Chen, K., Huang, L., Lin, B., Zhou, Y., Zhao, Q., & Guo, Q. (2019). The number of items on each Stroop test card is unrelated to its sensitivity. Neuropsychobiology, 77(1), 38-44. Web.
Daniel, F., & Kapoula, Z. (2019). Induced vergence-accommodation conflict reduces cognitive performance in the Stroop test. Scientific Reports, 9(1), 1-24. Web.
Erdodi, L. A., Sagar, S., Seke, K., Zuccato, B. G., Schwartz, E. S., & Roth, R. M. (2018). The Stroop test as a measure of performance validity in adults clinically referred for neuropsychological assessment. Psychological Assessment, 30(6), 755–766. Web.
Houdé, O. (2019). 3-System theory of the cognitive brain: A post-Piagetian approach to cognitive development. Routledge. Web.
Roy, A., Kefi, M. Z., Bellaj, T., Fournet, N., Gall, D., & Roulin, J. L. (2018). The Stroop test: A developmental study in a French children sample aged 7 to 12 years. Psychologie Française, 63(2), 129-143. Web.
Scharfen, J., Peters, J. M., & Holling, H. (2018). Retest effects in cognitive ability tests: A meta-analysis. Intelligence, 67(1), 44-66. Web.
Spieler, D., & Schumacher, E. (Eds.). (2019). New methods in cognitive psychology. Routledge. Web.
Taylor, S., & Workman, L. (2021). Cognitive psychology: The basics. Routledge. Web.
Vitevitch, M. S. (Ed.). (2019). Network science in cognitive psychology. Routledge. Web.