Insomnia On-Switch


Insomnia is a sleep disturbance affecting 15 percent of Americans. Sleep deprivation is associated with a lack of concentration and memory loss, and Dr. Rachel E. Salas at Johns Hopkins University decided to prove her theory that people who routinely suffered from insomnia would not perform as well on a motor task that required the brain to be “plastic,” or highly adaptable, in other words. What the study found was the opposite, however. It turns out that insomniacs’ brains have a sort of “on” switch that may never switch off, and it is this trait that negatively affects their ability to sleep while simultaneously allowing them to perform better at retraining or rewiring their brain to perform a new motor task.

Dr. Salas and her team hooked each of the 28 members of the study up to several wires. Eighteen of the participants had suffered from insomnia for more than a year, and the other 10 reported never having sleep issues. Each participant was hooked up to an EEG to measure brain activity, and then a specific area of the brain, the motor cortex, was targeted to receive a painless FDA approved procedure: TMS, or transcranial magnetic stimulation. An electrode was attached to one thumb, and then researchers sent tiny electrical pulses to the brain’s motor cortex to measure the involuntary movements of participants’ thumbs. What they discovered was the opposite of what was expected.

Notes were taken on each individual’s involuntary thumb movements. Each person’s movement would be particular to them. One person’s thumb might move left and up, another’s, right and up or right and down, and so on. This is not spectacular; the main thing is that it is consistent. Next, the TMS machine was turned off and participants were asked to retrain their thumb: to essentially move the thumb in the two directions opposite to how it had moved before. So for someone whose digit had moved right and down, they were asked to move it up and to the left. Across the board what was discovered was that it was the good sleepers who were less switched on and who had more difficulty retraining their thumbs than the insomniac group. The group who has difficulty sleeping had more brain activity while moving their thumbs in the new direction, and also were more easily able to accomplish the task.

Salas says this has led to the realization that insomnia is not a nighttime disorder, but is something sufferers experience 24 hours a day, seven days a week. Their switch stays on day or night, making it more difficult for sleep to be achieved, because the condition makes their brains essentially race. It does not mean, she stresses, that poor sleepers are higher strung, but that their brains process information at a heightened level. Most importantly, this does not change when they attempt sleep; their brains are always running, sparking from thought to thought, and this is what poor sleepers often report as being largely causative in their inability to sleep. Because of the heightened pace in the area of their brain responsible for movement their sleep is disrupted more, and they have more waking cycles throughout the night.

It is unclear if the increased brain activity is the cause or the result of sleeplessness. What is interesting, however, is that because researchers now know about this metaphoric “on” switch in the brains of insomniacs, sleep aids may be rethought altogether, with the results of this study and those it sparks being a crux of which direction to go in next.

By Julie Mahfood


Today Health
Hub, Johns Hopkins