Can the mental fatigue of gamers be tracked?

Ben Wisbey
4 min readNov 9, 2021

We can measure pretty much anything now days. But the human body still throws up some challenges as we attempt to understand and measure it.

One such trait is mental fatigue. We have all experienced it, and we can all associate it with less than ideal choices or poor performance. However, can we actually measure it? And more specifically, can we measure it in gamers?

EEG and Mental Fatigue

EEG (electroencephalogram) measures brain wave activity, and there is a consensus that different brain wave frequencies are associated with different activities. For example, slower waves such as delta are associated with rest or sleep, while higher waves such as beta are associated with attention and focus.

EEG measures brain wave activity with different frequencies associated with different brain functions

A quick Google search shows that there is plenty of research that uses EEG to assess mental fatigue. While on the surface this looks great, once you get into the details, things get much murkier.

Most of the research shows mental fatigue being associated with an increase in slower waves, mainly theta. However, there is no gold standard for measuring mental fatigue so most of the research tries to induce a fatigued state by doing repetitive mental challenges for extended period, such as 3 hours of repetitive arithmetic.

This then raises the question, are you assessing fatigue or drowsiness (i.e. boredom) as the subject loses motivation and ‘switches off’ during the challenge.

One interesting piece of research shows that when pilots were mentally fatigued during a lab based challenge, changes in EEG are evident, but when they were fatigued while flying a plane the changes differ to what is seen in the lab. The explanation for this was that the pilots concentrated harder to overcome fatigue when flying, compared to the lab where the outcome of the fatigue didn’t have consequences.

Overall, there is plenty of research showing a relationship between EEG and fatigue, but the details differ, and even conflict at times. It appears that the changes that occur with fatigue are task dependent, and creating a good model relies on the subject maintaining full effort throughout the challenge.

Heart Rate Variability (HRV) and Mental Fatigue

Heart rate variability analyses the beat-to-beat variation in your heart rate to determine autonomic nervous system response. This has long been used to assess stress and physical fatigue, but there is also some research showing a decrease in variability is associated with increased mental fatigue.

HRV is the variation in time between consecutive beats

Assessing HRV is much cleaner than EEG, but still, there are many statistical methods used, each giving varying strength of relationship with fatigue.

MaddCog’s Approach

From the published research it was clear that it was possible to assess mental fatigue from EEG and HRV, but there also seemed to be several challenges. The EEG research wasn’t consistent, there was no research specific to gaming, and very little of the research used single lead dry EEG like we needed to in order to offer an easy to use experience.

We undertook our own controlled trials on fifty gamers where they completed a repetitive gaming challenge for 60 minutes, with the added motivation of a shared leader board and prizes for top performers. During the challenge we monitored their game performance and their sleepiness which allowed us to omit data from the gamers who lost motivation during the challenge. This left us only with data that we were confident represented a change in mental fatigue.

These controlled trials allowed us to determine consistent changes in EEG and which HRV measures were most useful. And by combining the two, the mental fatigue prediction model was able to become quite strong.

While MaddCog isn’t the first group to develop a mental fatigue prediction model, it is the first we are aware of that is specific to gamers. Subsequent research has shown a link between predicted mental fatigue and gaming performance for most serious gamers.

MaddCog’s software provides live feedback on mental fatigue while you game, and then provides suitable recommendations to take breaks between games based on how sensitive your game performance is to mental fatigue.

Key References

While there are hundreds of published research articles, a recommended next step if you are interested in this topic, is the following article.

Hu, X. and Lodewijks, G. 2020. Detecting fatigue in car drivers and aircraft pilots by using non-invasive measures: The value of differentiation of sleepiness and mental fatigue. Journal of Safety Research, 72, 173–187.