Stroop effect
The Stroop effect is a well-known phenomenon in cognitive psychology that highlights the challenge of naming the ink color of a word when the word itself denotes a different color. For instance, when the word "red" is printed in green ink, it requires more time and cognitive effort to accurately identify the ink color compared to simply naming the color of a solid rectangle. This effect serves as a measure of cognitive flexibility and attentional control, and it has been extensively studied in relation to attention, memory, and processing speed.
Originally documented by John Ridley Stroop in 1935, the Stroop effect has evolved into various testing formats, including computerized versions. Theories explaining the Stroop effect suggest that the brain processes words more automatically than colors, leading to delays when tasks conflict. The phenomenon is also influenced by age, with young children and older adults displaying varying levels of interference.
Additionally, variations of the Stroop task exist—such as the emotional and directional Stroop—which illustrate the interference between automatic reading and visual processing. The Stroop effect is significant in clinical settings, aiding in the assessment of conditions like ADHD, Alzheimer's disease, and other cognitive disorders, thereby reinforcing its relevance in both psychological research and mental health evaluations.
On this Page
Subject Terms
Stroop effect
The Stroop effect is a cognitive psychology phenomenon that describes the difficulty of naming the ink color of a printed word while ignoring the word itself. When the word is a color-word printed in an incongruent color (for example, the word green printed in purple ink), it frequently takes more time to name the ink color. The degree of time varies from person to person, but this interference in visual processing is a measure of cognitive function and flexibility and attentional control. The Stroop effect is studied in research on attention, memory, and processing speed. It is also used in clinical and educational evaluations aiding the diagnoses of attention deficit hyperactivity disorder (ADHD), early onset Alzheimer’s disease, dyslexia, reading disabilities, and traumatic brain injury.
Overview
The Stroop effect was first documented in 1935 by John Ridley Stroop for his doctoral dissertation in experimental psychology. In his original set of studies, Stroop contrasted the time it took participants to name the color of various rectangles versus naming the color of color-words printed in incompatibly colored ink. For example, the Stroop effect occurred when participants found it more difficult to name the ink color of the word red printed in green ink than it was to name the ink color of a green rectangle.
Although Stroop conducted his experiments using paper cards and a stopwatch, a three-page standardized version of the Stroop task was published in 1978. Using two testing conditions, the Stroop effect was measured by subtracting the time it takes to name the color of rectangles on the control card from the time it takes to name the ink color of incompatibly colored color words on the experiment card. The Stroop effect is now typically measured using a computerized version of the task.
Several explanations for the mysterious Stroop effect have been suggested. First, the theory of automaticity originally proposed by James Cattell in 1886 supports the idea that reading words is a more practiced and automatic process than identifying colors. Therefore, it takes more time to name the ink color than it does to simply read the word. The speed of processing theory holds that the brain processes words faster than colors, creating an information lag when asked to name the incongruous color of a printed word. Another explanation of the Stroop effect is that two different areas in the brain are activated at the same time during the task, causing interference in processing of the information. The parallel distributed processing model suggests that it is the relative strengths of the different neurological pathways for processing the separate tasks of color and word recognition that cause interference.
There are no significant differences in the Stroop effect between men and women. However, there are several differences based on age. Young children who have not yet learned to read rarely experience the Stroop effect. Adults over the age of sixty experience the greatest Stroop effect, probably due to deterioration in cognitive performance with advanced age.
There are many variations of the Stroop task that elicit the Stroop effect such as the number Stroop, the emotional Stroop, the animal Stroop, and the directional Stroop. In each of these tasks, the automatic action of reading and the associated meaning of the words appears to interfere with the visual processing of colors. This interference increases the time it takes to respond to the task.
Despite a lack of consensus over the explanation of the Stroop effect, the Stroop task is an enduring staple in cognitive psychology research and mental health testing. Studies have found that the amount of interference is increased among patients with neurodegeneration due to brain damage, dementia, or other diseases, as well as ADHD, schizophrenia, depression, and other disorders. The Stroop effect has also been used to examine the process of cognitive development, with several studies pointing to a connection between the effect and working memory.
Bibliography
Baars, Bernard, and Nicole M. Gage. Fundamentals of Cognitive Neuroscience: A Beginner’s Guide. Waltham: Academic, 2013. Print.
Cherry, Kendra, MSEd. "How the Stroop Effect Works." Reviewed by Shereen Lehman, MS. Verywell Mind, 13 Nov. 2023, www.verywellmind.com/what-is-the-stroop-effect-2795832. Accessed 17 Sept. 2024.
De Young, Raymond. "Using the Stroop Effect to Test our Capacity to Direct Attention." School of Natural Resources & Environment. U of Michigan, 27 Feb. 2015. Web. 28 May. 2015.
Hutchison, Keith A., David A. Balota, and Janet M. Ducheck. “The Utility of Stroop Task Switching as a Marker for Early-Stage Alzheimer’s Disease.” Psychology and Aging 25.3 (2010): 545–59. Print.
MacLeod, Colin M. “The Stroop Task in Cognitive Research.” Cognitive Methods and Their Application to Clinical Research. Eds. Amy Wenzel and David C. Rubin. Washington: APA, 2005. Print.
Samuels, Jay, et al. “The Stroop Color-Word Test: Genetic and Environmental Influences; Reading, Mental Ability, and Personality Correlates.” Journal of Educational Psychology 95.1 (2003): 58–65. Print.
Science Buddies. "Seeing Science: Exploring Color Perception with the Stroop Effect." Scientific American. Scientific American, 11 Dec. 2014. Web. 28 May. 2015.
Song, Yongning, and Yuji Hakoda. “An Asymmetric Stroop/Reverse-Stroop Interference Phenomenon in ADHD.” Journal of Attention Disorders 15.6 (2011): 499–505. Print.
Sternberg, Robert, and Karin Sternberg. Cognitive Psychology. 6th ed. Belmont: Wadsworth, 2012. Print.
Theeuwes, Jan. “Automatic Control of Visual Selection.” The Influence of Attention, Learning, and Motivation on Visual Search. Eds. Michael D. Dodd and John H. Flowers. New York: Springer, 2012. 23–62. Print.
Van der Elst, Wim, et al. “The Stroop Color-Word Test: Influence of Age, Sex, and Education; and Normative Data for a Large Sample across the Adult Age Range.” Assessment13.1 (2006): 62–79. Print.