What Are Cognitive Functions?

Memory, speed, reasoning, language abilities and more.

Posted Jun 28, 2020

In psychological health research, a person’s ability to think, otherwise known as their cognitive functions, is a crucial subject of research. The cognitive functions are a variety of different, but related, skills involving learning and problem-solving. Together, these are some of the most important and impressive abilities that the brain is capable of.

The cognitive functions are collectively known by several different names. Different researchers with different expertise call them general cognitive function, cognitive ability, cognitive capacity, and intelligence. This is the same “intelligence” of the intelligence quotient, better known as IQ. High-quality IQ tests measure the same thing as what health psychologists might call general cognitive function. Because standardized IQ tests are commonly given in school, they have been repurposed by health researchers to measure a person’s pre-morbid cognitive function.

In other words, if you measure cognitive function early in life before major health problems arise that might impact cognitive function, you can make stronger claims about whether these health problems predict cognitive dysfunction. This work is part of a subfield called cognitive epidemiology.

The individual cognitive functions themselves are numerous and diverse. Many make more intuitive sense than general cognitive function, which is vague. The memory domain represents your ability to remember things. The speed domain represents how fast you can think. Others are not as intuitive. Reasoning represents your ability to solve new problems, particularly with nonverbal information, and verbal fluency represents your ability to work with verbal information. Visual-spatial ability represents your proficiency in interacting with physical objects in the world. Humans rely heavily on our sense of sight, but we also are unique in how good we are at manipulating our physical environments and doing things like making tools. Hence, humans have developed distinctly strong visual-spatial abilities.

The individual cognitive functions themselves are not perfectly distinct, however. For instance, memory can be subdivided into episodic memory, which assesses your ability to remember details like items in a list or events from a story, and working memory, which is your ability to simultaneously keep information in mind, like when you try to remember a telephone number. Though all cognitive abilities tend to be correlated, that is, if you are good at one thing you tend to be good at all the others, these memory abilities tend to be more strongly correlated to each other than to other cognitive abilities, e.g. speed.

We are starting to learn how the individual functions are important for health, as well. For instance, take memory again. All of these abilities tend to decline as you age. If you are healthy, the decline is slow. In certain cases, the decline is faster, however. In people with Alzheimer’s disease, for example, the memory domain in particular declines more rapidly than we would expect. You can observe these declines in memory before you can classify a person as having dementia. Ideally, we can find more ways to use tests of cognitive function to reliably identify psychological health problems sooner than we would otherwise. When used properly, tests of the cognitive functions are a powerful healthcare tool with wide applications.

References

Deary, I. J., & Batty, G. D. (2007). Cognitive epidemiology. Journal of Epidemiology & Community Health, 61(5), 378-384.

Dowling, N. M., Farias, S. T., Reed, B. R., Sonnen, J. A., Strauss, M. E., Schneider, J. A., ... & Mungas, D. (2011). Neuropathological associates of multiple cognitive functions in two community-based cohorts of older adults. Journal of the International Neuropsychological Society: JINS, 17(4), 602.

Rabin, L. A., Paré, N., Saykin, A. J., Brown, M. J., Wishart, H. A., Flashman, L. A., & Santulli, R. B. (2009). Differential memory test sensitivity for diagnosing amnestic mild cognitive impairment and predicting conversion to Alzheimer's disease. Aging, Neuropsychology, and Cognition, 16(3), 357-376.