How the Stroop Test Screens for Signs of Early Alzheimer's

The Stroop test, also referred to as the Stroop Color Word Test or the Stroop Effect, is a test dating back to the 1930s that measures cognitive functioning. It may be used as part of the assessment process when conducting an evaluation to determine if someone has mild cognitive impairment, Alzheimer’s, oranother type of dementia.

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Doctor consulting with an older woman

What Does the Stroop Test Contain?

The Stroop Test consists of colors that are written in words but in the wrong color ink. The test-taker has to be able to state the color that the word is written in and be able to ignore whatever the actual word is. For example, if you see the word “red” but it’s written in blue ink, the correct answer would be “blue”.

Stroop Test Results

Older adults who do not have any cognitive impairment have, on average, a slower response time than younger and middle-aged adults, but they typically answer the questions correctly.

People with mild cognitive impairment, Alzheimer’s or anotherdementia, on the other hand, will be slower in answering but also will have a significantly higher rate of incorrect answers because of their decline in processing information and the inability to ignore one stimulus (the word) while focusing on the other one (the color).

What Does the Stroop Test Identify?

The Stroop Test has been associated with impairment specifically in the prefrontal cortices of the brain, especially in earlier stages of Alzheimer’s. As Alzheimer’s progresses into themiddleandlate stages, the Stroop effect is not a valid indicator of the location or extent of impairment in the brain.

Variations of the Stroop Test

Variations of the Stroop Test have been developed and tested recently, particularly with the goal of assessing executive functioning early in Alzheimer’s. Rather than continue the same set of directions throughout the test, the new version required the participants to switch back and forth between two different sets of directions.

For example, on one section of the test, they might have to identify the color the word is written in, and in another section of the test, they might have to read the word and ignore the color that the word is written in.

Other variations might include a written word that is not a color, such as the word “five” in a certain color ink. Another variation includes geometric words and shapes, although this version has been used to study the function of the left and right hemispheres of the brain, rather than cognitive impairment.

How Accurate Is the Test?

A Word From Verywell

While there are many screening tests that help identify symptoms of dementia, the Stroop test is one that is more effective at pointing out those with just the early, or mild, stages of dementia such as mild cognitive impairment. Its ability to test executive functioning sets it apart as an important component of a comprehensive assessment of cognition.

1 SourceVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Gier VS, Kreiner DS, Solso RL, Cox SL.The hemispheric lateralization for processing geometric word/shape combinations: the Stroop-shape effect.J Gen Psychol. 2010;137(1):1-19. doi:10.1080/00221300903293022Additional ReadingPena-Casanova J, Quinones-Ubeda S, Gramunt-Fombuena N et al. Spanish Multicenter Normative Studies (NEURONORMA Project): Norms for the Stroop Color-Word Interference Test and the Tower of London-Drexel.Archives of Clinical Neuropsychology. 2009;24(4):413-429. doi:10.1093/arclin/acp043Alzheimer’s Society. The Stroop Test.Dementia and Geriatric Cognitive Disorders EXTRA. 2011 Jan-Dec; 1(1): 190–201. Neural Correlates of Stroop Performance in Alzheimer’s Disease: A FDG-PET Study.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199888/National Institutes of Health. National Institute on Aging. Developing New Cognitive Tests. http://www.nia.nih.gov/alzheimers/publication/6-advances-detecting-alzheimers-disease/developing-new-cognitive-testsPsychology and Aging. 2010, Vol. 25, No. 3, 545–559. The Utility of Stroop Task Switching as a Marker for Early-Stage Alzheimer’s Disease.http://www.scribd.com/doc/283607773/The-Utility-of-Stroop-Task-Switching-as-a-Marker-for-Early-Stage#scribdThe Environmental Psychology Lab. School of Natural Resources and Environment, University of Michigan. Stroop Effect.http://www.snre.umich.edu/eplab/demos/st0/stroopdesc.html

1 Source

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Gier VS, Kreiner DS, Solso RL, Cox SL.The hemispheric lateralization for processing geometric word/shape combinations: the Stroop-shape effect.J Gen Psychol. 2010;137(1):1-19. doi:10.1080/00221300903293022Additional ReadingPena-Casanova J, Quinones-Ubeda S, Gramunt-Fombuena N et al. Spanish Multicenter Normative Studies (NEURONORMA Project): Norms for the Stroop Color-Word Interference Test and the Tower of London-Drexel.Archives of Clinical Neuropsychology. 2009;24(4):413-429. doi:10.1093/arclin/acp043Alzheimer’s Society. The Stroop Test.Dementia and Geriatric Cognitive Disorders EXTRA. 2011 Jan-Dec; 1(1): 190–201. Neural Correlates of Stroop Performance in Alzheimer’s Disease: A FDG-PET Study.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199888/National Institutes of Health. National Institute on Aging. Developing New Cognitive Tests. http://www.nia.nih.gov/alzheimers/publication/6-advances-detecting-alzheimers-disease/developing-new-cognitive-testsPsychology and Aging. 2010, Vol. 25, No. 3, 545–559. The Utility of Stroop Task Switching as a Marker for Early-Stage Alzheimer’s Disease.http://www.scribd.com/doc/283607773/The-Utility-of-Stroop-Task-Switching-as-a-Marker-for-Early-Stage#scribdThe Environmental Psychology Lab. School of Natural Resources and Environment, University of Michigan. Stroop Effect.http://www.snre.umich.edu/eplab/demos/st0/stroopdesc.html

Gier VS, Kreiner DS, Solso RL, Cox SL.The hemispheric lateralization for processing geometric word/shape combinations: the Stroop-shape effect.J Gen Psychol. 2010;137(1):1-19. doi:10.1080/00221300903293022

Pena-Casanova J, Quinones-Ubeda S, Gramunt-Fombuena N et al. Spanish Multicenter Normative Studies (NEURONORMA Project): Norms for the Stroop Color-Word Interference Test and the Tower of London-Drexel.Archives of Clinical Neuropsychology. 2009;24(4):413-429. doi:10.1093/arclin/acp043Alzheimer’s Society. The Stroop Test.Dementia and Geriatric Cognitive Disorders EXTRA. 2011 Jan-Dec; 1(1): 190–201. Neural Correlates of Stroop Performance in Alzheimer’s Disease: A FDG-PET Study.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199888/National Institutes of Health. National Institute on Aging. Developing New Cognitive Tests. http://www.nia.nih.gov/alzheimers/publication/6-advances-detecting-alzheimers-disease/developing-new-cognitive-testsPsychology and Aging. 2010, Vol. 25, No. 3, 545–559. The Utility of Stroop Task Switching as a Marker for Early-Stage Alzheimer’s Disease.http://www.scribd.com/doc/283607773/The-Utility-of-Stroop-Task-Switching-as-a-Marker-for-Early-Stage#scribdThe Environmental Psychology Lab. School of Natural Resources and Environment, University of Michigan. Stroop Effect.http://www.snre.umich.edu/eplab/demos/st0/stroopdesc.html

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What Does the Stroop Test Contain?#

Stroop Test Results#

What Does the Stroop Test Identify?#

Variations of the Stroop Test#

How Accurate Is the Test?#

A Word From Verywell#