Altered Brain Activation During Response Inhibition in Obstructive Sleep Apnea

Ayalon, L., Ancoli-Israel, S., & Drummond, S. (2009). Altered brain activation during response inhibition in obstructive sleep apnea. Journal of Sleep Research, 18(2), 204-208. Retrieved from EBSCOhost. doi:10.1111/j.1365-2869.2008.00707.x

Chapter 13 in our textbook describes many sleep disorders, with sleep apnea being one of them.  Sleep apnea is the inability to breathe while sleeping.  People with this sleep disorder have to wake up in order to breathe.  The current study is examining obstructive sleep apnea (OSA), which is having repeated occurrences of upper airway obstruction during sleep.  Several studies have been conducted to research the behavioral effects of OSA, but not many studies have been done on the neural connections underlying these behavioral effects.  The researchers of this study used the “Go-NoGo” task, a response inhibition task, to determine if participants with OSA would show a poorer performance on this task as well as a decrease in cerebral activation in brain regions related to tasks.  Fourteen participants had OSA and 14 participants were in the control group.  The participants were studied using fMRI (functional magnetic resonance imaging).  During the fMRI, participants completed the Go-NoGo task, a short-term memory task, and a sensorimotor task.  For the Go-NoGo task, participants were asked to press a button as fast as they could every time they saw a shape (Go stimuli) and to withhold their responses every time they saw a small pentagon (NoGo stimuli).  This task lasted a little more than six minutes.  After participants completed the Go-NoGo task, they were given the Stanford Sleepiness Scale, Karolinska Sleepiness Scale, and a 10-point Likert scale that assessed these factors: how difficult the task was, their concentration ability, how much effort they put into the task, and also how much motivation they had to perform the task efficiently.  After analyzing the results, the researchers found that those participants with OSA displayed more false positives, or “errors of commission,” during the NoGo trials.  The participants with OSA showed a decrease in brain activation during the NoGo trials in the left postcentral gyrus, cingulate gyrus, inferior parietal lobe, right inferior frontal gyrus and insula, and the right putamen.  These results show that individuals with OSA have impaired cerebral activation during cognitive tasks like the response inhibition task used in this study.  Studies such as this one will help people to better understand that the reason for cognitive deficits in individuals with OSA may be due to the underlying abnormalities in the way their brain functions.