A small new study sheds some light on how the brains of people with insomnia and good sleepers differ.
Researchers from the Johns Hopkins University School of Medicine found that there is more activity, adaptability to change (plasticity) and increased "excitability" of neurons in the motor cortex of the brain, which controls movement, in people with insomnia.
For the study, published in the journal Sleep, researchers examined 28 adults (18 of whom had insomnia for a year or more, and 10 of whom were good sleepers) as they were administered 65 electrical pulses on their thumbs with transcranial magnetic stimulation. The researchers kept track of the participants' involuntary thumb movements in response to the pulses; the participants also wore accelerometers to track the direction and speed of the thumb movements.
Then, the researchers spent 30 minutes training the participants to move their thumb in the other direction, against the direction of their involuntary movement. They associated the participants' ability to learn how to move their thumbs in the newly trained direction as an indicator of increased brain plasticity.
While researchers expected plasticity to be higher among the good sleepers, they found that the people with insomnia actually had more evidence of greater brain plasticity. However, they noted that what this plasticity means -- or whether it's a good or a bad thing -- has yet to be determined.