Those who suffer from metal fatigue are drained on their energy abnormally fast and it requires an abnormally long recovery time to get back to the starting position- which was already low. This means that they cannot be active for as long, or as often, as before, because in order to live a normal life one must be able to perform activities over and over again.
How is it cured?
– Today, we lack effective treatment, and rehabilitation can take many years. Many patients won´t be able to ever work again. It´s easy to understand that the individual suffering is big, but the costs for society are also very large.
What causes it?
– We currently don´t know enough about what causes mental fatigue, but our theory is that the supply of energy isn´t functioning well and the energy balance cannot be restored. In this study, we have investigated how the brain is activated in people suffering from mental fatigue after a traumatic brain injury, and how mental work over a longer time span of a total of 2.5 hours affects them. We have used functional near-infrared spectroscopy (fNIRS), which can measure superficial cortical activity while performing cognitive tests. We found that the brain’s frontal activity was clearly impaired in the mental fatigue group compared to the healthy control group. It became especially clear when the tasks became more mentally demanding. This difference between the group suffering from mental fatigue and the control group was already present at the start. In addition, the group suffering from mental fatigue was unable to improve their cognitive performance in repeating tests, which the control group did. This indicates that the brain does not work effectively for those who suffer from mental fatigue after a traumatic skull injury, which can be a cause of a perceived energy shortage after a period of mental stress.
What will happen now?
– We hope that in future studies, we will deepen our knowledge of the brain’s energy supply in mental fatigue and also get a better understanding of how the brain works. Today, very little research has been done on underlying causes of mental fatigue. Better knowledge of underlying factors for mental fatigue could contribute to the development of more effective treatment methods in the future.
Simon, what other studies are you involved in right now?
– I´m using fNIRS in several other projects. We are investigating mental fatigue caused by hypothyroidism and mental fatigue in exhaustion disorder. Another study is about whether general fatigue can affect the cognitive control among healthy subjects. We are also studying cognition among 8-9-year-old children solving mathematical problems in a school environment.
Funding
This study was founded by the Local Research and Development Council Göteborg and Södra Bohuslän. Swedish Research Council, Swedish Childhood Cancer foundation, and Swedish governmental support under the ALF agreement.