Researchers have uncovered new evidence as to why people with insomnia struggle to concentrate even in the absence of a clear cognitive problem.
Published in the journal Sleep, the study used a functional magnetic resonance imaging scan to evaluate 25 people with primary insomnia and 25 self-described good sleepers as they performed a working memory task.
The findings, the researchers explain, revealed that while both groups performed similarly in regards to the task, those with insomnia had to work harder to achieve the same results.
"We found that insomnia subjects did not properly turn on brain regions critical to a working memory task and did not turn off 'mind-wandering' brain regions irrelevant to the task," lead author Sean Drummond, an associate professor in the department of psychiatry at the University of California, San Diego, said in a statement.
Furthermore, as the task grew harder, good sleepers engaged more resources within the brain's working memory network even as those with insomnia struggled to do so.
"Based on these results, it is not surprising that someone with insomnia would feel like they are working harder to do the same job as a healthy sleeper," Drummond said.
The study, according to the researchers, is the first to characterize functional MRI differences in the working memory in those with primary insomnia and, as such, marks a key step in treating the disorder.
"The data help us understand that people with insomnia not only have trouble sleeping at night, but their brains are not functioning as efficiently during the day," Drummond said. "Some aspects of insomnia are as much of a daytime problem as a nighttime problem. These daytime problems are associated with organic, measurable abnormalities of brain activity, giving us a biological marker for treatment success."