This blog is the third in a series of guest posts on technology and the brain to celebrate Scientific American Mind’s 10-year anniversary. The magazine’s special November/December issue similarly highlights the interface between code and thought in profiling a future, more digital YOU.
Video games are an increasingly common pastime, especially for children, adolescents and young adults. As humans of all ages spend more and more time gaming, scientists as well as pundits have wondered whether this common activity has important effects, positive or negative, on brain development or cognitive function. Lively debates abound on blog sites on this controversial topic, with highly polarized camps. Some suggest that video games may decrease attention and promote antisocial behavior or even violence. Others believe that video games can actually improve brain and cognitive function. One thing is certain: video games are here to stay and their introduction represents an unintended social experiment with as widespread implications, good or bad, as the introduction of radio or television.
One aspect of video games that is less often discussed is their potential to test or screen for cognitive deficits. The idea is that if scoring well on a video game requires a specific cognitive skill, then individuals who score especially poorly on this game may have a deficit in that skill. This may be particularly true of video games that are marketed as “brain training” games. Irrespective of whether such games can actually improve brain function, is it possible to use these games for testing attention, working memory, visuospatial memory, processing speed and response inhibition? These domains may be impaired in a wide variety of medical conditions such as dementia, depression, attention deficit hyperactivity disorder (ADHD), liver disease and renal disease. More importantly, early, subtle or insidious cognitive deficits related to these conditions may remain undiagnosed and untreated for years.
My colleagues and I were specifically interested in the cognitive impairment that occurs in patients with cirrhosis of the liver, known as hepatic encephalopathy. When the liver develops cirrhosis, it fails to clear certain toxins and metabolic byproducts from the blood; these chemicals thus accumulate and impair brain function. Hepatic encephalopathy can range from subtle abnormalities of attention and concentration, sometimes called minimal hepatic encephalopathy, to profound impairments and even coma. Unfortunately, minimal hepatic encephalopathy cannot be diagnosed without complicated, lengthy, paper-and-pencil psychometric tests that need to be administered by trained psychologists. Because of this problem, the condition often remains undiagnosed and untreated. It thus continues to negatively affect patients’ quality of life, including their ability to work and, importantly, to drive safely.
We wondered whether computer brain-training games developed by Lumosity could identify subtle, undiagnosed cognitive impairments in patients with cirrhosis. We chose these games because they had certain properties that made them very attractive as potential tests of minimal hepatic encephalopathy. First, they happen to be computer-based adaptations of pre-existing, non-computerized, validated psychometric tasks that test cognitive domains known to be important in minimal hepatic encephalopathy. Second, they are short and self-explanatory: each test takes about 45 seconds, so a trial run and two test runs can be done in less than three minutes. Third, they are relatively inexpensive and widely available on computers, tablets and smartphones. Fourth, and perhaps more important, the tests are adaptive, which means they become harder or faster as patients answer items correctly or easier and slower as patients answer incorrectly. Computer-adaptive tests require less time–or, given the same time, can produce a more accurate score–than a non-adaptive test.
We looked at five of Lumosity’s brain teaser-like games administered on an iPad, each one challenging a different cognitive domain. Two games called Color Match and Memory Matrix were found to identify statistically significant deficiencies between patients with cirrhosis and appropriate controls. Color Match is a computerized version of the Stroop task, in which the names of two colors appear on the screen and the player must read the top word and decide whether or not it matches the actual color of the bottom word. It is a test of selective attention, cognitive flexibility and response inhibition. Memory matrix, which is a computerized adaptation of the Corsi block tapping task, shows players a grid of tiles, has the grid disappear and then asks them to recreate it. It is a test of visuospatial working memory. These two brain-training games can potentially be used to identify cirrhotic patients who suffer from minimal hepatic encephalopathy.
While larger validation and standardization studies will certainly need to be done before Color Match and Memory Matrix can be used in clinical practice, our study serves as an important proof of principle and highlights the potential of brain training games as screening tests for medical conditions that cause cognitive impairment. The games will have to be carefully selected or specifically developed to test the cognitive domain of interest. They also will have to be adaptive, short, inexpensive and widely available on existing operating systems.
If brain training games are used as clinical screening tests, they will have to go through the same rigorous assessment required of every new clinical test, including independent validation, standardization for age and other factors, and determination of appropriate diagnostic threshold values for specific clinical conditions. Even though the tests may be available to laypeople on their home computer or iPad, the results will still need to be interpreted by clinical experts, and there are risks to misinterpretation. Finally, it is unlikely that a particular cognitive deficit a game identifies will be specific to a clinical condition. For example, a deficit in attention could be caused by ADHD, encephalopathy, sleep deprivation or even certain medications. Thus critical interpretation of test results in the context of a person’s medical history is paramount.
Despite these reservations, brain training games hold significant promise as quick, inexpensive and potentially accurate screening tests for cognitive deficits that may otherwise remain undiagnosed and untreated for years. They may also yield new insights about the patterns of cognitive deficits that characterize clinical conditions such as cirrhosis or depression. Video games may or may not improve your brain, but they can certainly test it.
Image: American Journal of Gastroenterology 2014; 109:316-323; doi:10.1038/ajg.2013.306; https://www.nature.com/ajg/journal/v109/n3/full/ajg2013306a.html
>>Next in the series: “Giving the Brain a Buzz: The Ultimate in Self-Help or a Dangerous Distraction?”