Researchers have always known there was something different about people with chronic insomnia. A new study sheds some light on what that “something” might be. Dutch scientist Ellemarije Altena at the Netherlands Institute for Neuroscience of the Royal Netherlands Academy of Arts and Sciences studied a group of older adults, some of whom suffered from insomnia. She had them carry out various tasks, including thinks like pressing a button as soon as they saw a star on a screen, pressing when they saw a ‘p’ on the screen but not if they saw a ‘d’, and coming up with as many words as possible in a certain category.
Patients with a chronic lack of sleep performed better than the control group (members of the study who don’t have insomnia) in the simplest test, i.e. the one with the star, but poorer on the task with the ‘p’ and ‘d’. Yet during the tests involving thinking of words, the insomniacs fell behind the control group.
From a news release about the study:
The researcher examined the brain activity of the study participants during the different tasks. During the word task the brain activity was lower in people with sleeping problems compared to the control group in regions important for performing the task. Their good performance despite this could be due to a state of hyperarousal. Hyperarousal is similar to a persistent mild form of stress. Your brain therefore makes use of other mechanisms to compensate for the lack of sleep. It is not known whether hyperarousal has negative side effects, although stress can lead to mental and physical problems.
Altena discovered that the brains of insomnia patients not only function differently but also have a different appearance. The grey matter in certain regions of the brain has a reduced density. And the worse the insomnia, the lower the density in one of these regions, the orbitofrontal cortex. This last observation might indicate that the abnormalities in the grey matter give an increased risk of insomnia. However, the reduced density of the grey matter does not necessarily mean that the brain functions less well. In the brain, size is not the only factor that counts.