Whenever you learn something new or practice a skill, your brain changes too. People don’t realise that the same is true with playing video games.
Video games are a training ground; full of motivational pulls to navigate worlds, solve puzzles, form strategies, react quickly, empathise with characters, and plan to beat bosses. Depending on the type of game, we can use our memory, attention and problem-solving skills to win. Using these skills shapes our brain so that it becomes more proficient and efficient in these skills. It’s an area with a great amount of potential – especially because video games are so engaging – but we still know little about the specific brain changes that occur with prolonged video game play.
A study by West and colleagues in 2017 (1) sought to investigate how navigation strategies used in video games affect the structure of a brain region called the hippocampus.
The hippocampus (from the Greek for ‘seahorse’, because it looks like a seahorse) is an area that is often implicated in memory. You may have heard that it is one of the areas that is affected in Alzheimer’s disease (2).
Proof that the hippocampus looks like a seahorse. From Wikipedia Commons. https://commons.wikimedia.org/wiki/File:Hippocampus_and_seahorse.JPG
It also plays a central role in spatial navigation – knowing how to get from one place to another. If you have heard of the hippocampus before, you have perhaps heard of the London taxi driver study (3), which found that London taxi drivers have an enlarged hippocampus, which is related to the vast amount of spatial information they need to remember to transport their passengers.
West and colleagues found something similar but with two differences: hippocampal volume change was found when navigating a virtual environment (via video games) and the differences in hippocampal grey matter gains depended on the type of spatial navigation strategy used.
We have two main navigation systems that are represented in our brain. The first one is spatial and relies on learning the relationship between landmarks in an environment, which is housed in the hippocampus. The other is a response learning strategy that involves memorising actions from a starting point, which is governed by the caudate nucleus.
Here’s an easier way to think about it: say you wanted to go to the hospital from your house. A spatial strategy (using the hippocampus) would navigate using the landmarks on the way – go north to the post office then turn right until you get to the shoe shop, turn left and keep on going until the hospital is on the right. A response learning strategy would just use directions – go north two blocks, right two blocks, left five blocks then the hospital is on the right.
Spatial navigation strategy
Both systems are useful and necessary to navigate the world. But the two brain regions underpinning these navigation strategies have an inverse relationship to each other; that means that an increase in structure or activity in one leads to a decrease in the other. Over-relying on one navigation system could cause the other one to shrink, which could have repercussions for other thinking and emotional skills that these regions are implicated in. One potential finding is that decreased hippocampal grey matter (a structural part of the brain composed of neuron bodies) has been implicated in the development of psychiatric disorders such as depression (3). The implication is that if you use over-use response-learning navigation strategies, your hippocampus may shrink, which could put you at risk for cognitive or mental health difficulties.
This is where West and colleagues’ study comes in. One of the experiments in the paper trained participants in a lab for 90 hours (over an average of 59 days) on either an action video game (which encourages the use of response-learning strategies) or a 3D platform video game (which encourages spatial strategies). Just focusing on the hippocampus, it was found that the action video game group had significantly decreased grey matter in the right hippocampus compared to the 3D-platform group. On the other hand, the 3D-platform group had increased grey matter in the left hippocampus compared to the action video game group.
Before training, participants were tested on a separate task to see whether they spontaneously prefer response-learning or spatial navigation strategies. It was found that, in the action video game group, people who preferred spatial strategies had an increased volume in the hippocampus after training compared to those who preferred response-learning strategies.
These findings suggest that the nature of the video game and the preferred navigation system interact to alter the structure of the brain in as little as two months. Findings like this may cause concern for people who enjoy action video games, but it’s not just playing action video games that will cause your brain to shrink. Action video games may encourage use of one navigation strategy but ultimately it depends on whether the person will use that strategy when playing the game.
First, I want to emphasise how well-designed this study is. Usually research into the effect of video games is correlational. Information at one time point on video game playing habits, measures of thinking and emotional skills and brain imaging is collected and related to each other. But in order to show that video game playing causes changes in thinking/emotional skills and the brain, we need to track this over time and carefully match who is playing games, what they are playing and how much they are playing it. With this study, the participants in each group were similar, randomly assigned to each group and played the game for roughly the same amount of time. From this, we can see that the changes in the brain are due to the type of game that they were playing.
One area that I am sceptical of that needs further research is whether the hippocampal changes associated with action video game play lead to cognitive and emotional difficulties. The researchers did not measure cognitive ability or psychiatric symptoms before or after video game play, so even though they assert that it may cause these types of difficulties, there is a lack of evidence whether it will. The action video game group had decreased grey matter in the right hippocampus but a meta-analysis (a large analysis combining results from many studies) found that people with depression have a reduced amount of grey matter in the left hippocampus (3). Regional grey matter changes provide a general view but the fine-level changes may be what is important here to relate it to cognition and emotion.
There is also a practical question of what this means for the design of video games. Many people play action video games worldwide, such as Call of Duty which was used in the current study. If response-learning strategies have a negative effect on brain structure, the navigation strategies in-game may need to be adapted to encourage use of spatial strategies. This could be achieved by removing the mini-map or by designing maps that change regularly. Of course, this will be met with contention in the gaming community, as many players rely on knowing a map well in order to git gud. Either way, if these findings are replicated in future studies and are shown to have effects on how we think and feel, there needs to be a conversation on how to address this.