Researchers have new clues as to why it's so hard to concentrate after a bad night's sleep.


A new study published in the journal Sleep[1] shows that even though people with insomnia and people without insomnia were able to perform equally on a working memory task, the brains of those with the condition did not work as efficiently.


Specifically, people without insomnia were able to pull more resources to the network of the brain responsible for working memory as the task grew in difficulty. But people with insomnia were unable to pull these resources.


Plus, insomniacs were unable to "turn off 'mind-wandering' brain regions irrelevant to the task," study researcher Sean P.A. Drummond, Ph.D., an associate professor in the department of psychiatry at University of California, San Diego, and the VA San Diego Healthcare System, said in a statement.


"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 added.


brain insomnia

The A column shows brains from good sleepers, while the B column shows brains from people with primary insomnia. The brain scans demonstrate brain activation in response to task difficulty.


The study is based on data from 25 people with insomnia and 25 people who were good sleepers; the study participants' average age was 32. For the study, the participants did a working memory task while they were undergoing functional MRI brain scans.



"This study suggests PIs [primary insomniacs] have a reduced ability to engage some task-appropriate brain regions and reduced ability to modulate task-irrelevant (i.e., default mode) brain regions during working memory performance," researchers wrote in the study. "If either of our potential explanations for this is correct (PIs require greater attention and/or effort during baseline or PIs are unable to disengage from default mode during active conditions), these phenomena may be experienced by PIs as increased cognitive difficulties."


HuffPost blogger and sleep expert Michael Breus, Ph.D., previously pointed out that insomnia could also contribute to emotional problems and even depression. He noted a study from University of Pittsburgh School of Medicine researchers, which showed that insomniacs have dysfunctional activity in a brain region[2] linked with emotion processing and regulation.



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  • ...Increase Stroke Risk


    Even without the typical risk factors, like being overweight or having a family history, short sleep can up your risk for stroke, according to 2012 research. Adults who regularly slept fewer than six hours a night had <a href="http://www.huffingtonpost.com/2012/06/11/sleep-stroke-risk_n_1586837.html">four times the risk of stroke symptoms</a>, HuffPost reported.




  • ...Lead To Obesity


    Too little sleep can spur some less-than-ideal food choices, including <a href="http://www.huffingtonpost.com/2013/02/25/sleep-portion-sizes-deprivation-food-calories_n_2735497.html">serving yourself larger portions</a>, and a hankering for junk food, thanks to some complicated hormonal changes that occur when you don't get sufficient shuteye. It seems that six hours of sleep or less <a href="http://www.huffingtonpost.com/2012/10/26/sleep-deprivation-obesity-leptin-ghrelin-insulin_n_2007043.html">bumps up production of the hunger hormone ghrelin</a> and limits leptin, which helps you balance your food intake, according to a 2012 review of 18 studies of sleep and appetite.




  • ...Up Diabetes Risk


    A pair of small studies from 2012 examined the link between poor sleep and insulin resistance, a telltale risk factor for diabetes. One found that among healthy teenagers, the <a href="http://www.huffingtonpost.com/2012/10/03/sleep-insulin-resistance-teens_n_1929374.html">shortest sleepers had the highest insulin resistance</a>, meaning the body is <a href="http://diabetes.niddk.nih.gov/dm/pubs/insulinresistance/#resistance">not using insulin effectively</a>, according to the National Institute of Diabetes and Digestive and Kidney Diseases. The second study examined fat cells, in particular, and found that cutting back on sleep <a href="http://annals.org/article.aspx?articleid=1379773">increased insulin resistance in these cells</a>, even when <a href="http://news.health.com/2012/10/15/sleep-deprivation-insulin-resistance/">diet and calorie intake were restricted</a>, Health.com reported.




  • ...Fuel Memory Loss


    You probably know that on the days when you are most tired, you're forgetful and unfocused -- but sleep deprivation can lead to <a href="http://www.sciencedaily.com/releases/2013/01/130127134212.htm"><em>permanent</em> cognitive issues</a>. The less we sleep, the less we benefit from the memory-storing properties of sleep. But additionally, a lack of sleep can cause <a href="http://www.huffingtonpost.com/2013/01/28/sleep-deprivation-memory-loss_n_2566999.html">"brain deterioration,"</a> according to a 2013 study, which may at least in part explain memory loss in seniors.




  • ...Damage Bones


    At least in rats, long-term <a href="http://ebm.rsmjournals.com/content/237/9/1101.full">sleep deprivation seems to contribute to osteoporosis</a>, according to a 2012 study. Researchers found <a href="http://www.huffingtonpost.com/2012/09/26/sleep-deprivation-bones-marrow_n_1898610.html">changes to bone mineral density and bone marrow</a> in the rodents when they were deprived of shuteye over a period of 72 days. "If true in humans, and I expect that it may be, this work will have great impact on our understanding of <a href="http://www.eurekalert.org/pub_releases/2012-09/sfeb-los_1091812.php">the impact of sleep deprivation on osteoporosis</a> and inability to repair bone damage as we age," Steven R. Goodman, Ph.D., editor-in-chief of Experimental Biology and Medicine, said in a statement.




  • ...Increase Cancer Risk


    A small (but growing) body of research suggests that short and poor sleep can up risk for certain types of cancer. A 2010 study found that among 1,240 people screened for colorectal cancer, the 338 who were diagnosed were <a href="http://onlinelibrary.wiley.com/doi/10.1002/cncr.25507/abstract">more likely to average fewer than six hours of sleep</a> a night. Even after controlling for more traditional risk factors, polyps were more common in people who slept less, according to the study. Getting just six hours of sleep a night has also been linked to an <a href="http://www.huffingtonpost.com/2012/09/06/sleep-breast-cancer-aggressive-deprivation_n_1854658.html">increase of recurrence in breast cancer patients</a>. The study's author has pointed to more and better sleep as a possible pathway of reducing risk and recurrence.




  • ...Hurt Your Heart


    The stress and strain of too little sleep can cause the body to produce more of the chemicals and hormones that can lead to heart disease, according to 2011 research. The study found that people who slept for six hours or less each night and have problems staying asleep had a 48 percent <a href="http://www.sciencedaily.com/releases/2011/02/110208091426.htm">higher risk of developing or dying from heart disease</a>.




  • ...Kill You


    It's not just heart problems that can lead to sleep-deprivation-related death. In fact, <a href="http://healthland.time.com/2010/09/02/lack-of-sleep-can-cause-depression-weight-gain-and-even-death/">short sleepers seem to die younger</a> of any cause than people who sleep about 6.5 to 7.5 hours a night, TIME reported. A 2010 study examined the impact of short sleep on mortality and found that <a href="http://www.journalsleep.org/ViewAbstract.aspx?pid=27894">men who slept for less than six hours of sleep a night were four times more likely</a> to die over a 14-year period. The study's authors called this link "a risk that has been underestimated."




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