Spatial memory is utilised for everyday tasks, such as remembering the location of a favourite restaurant, remembering how to get home even if you are required to take a detour from your typical route, or remembering where you left an item in your house.

"We have shown for the first time that sleep apnea, an increasingly common medical condition, might negatively impact formation of certain memories, even when the apnea is limited to REM sleep," said lead researcher Andrew Varga from New York University in the US.

"Our findings suggest memory loss might be an additional symptom for clinicians to screen for in patients with sleep apnea," Varga added.

The study involved 18 participants with severe sleep apnea. They were monitored for two nights during which time they played video games before and after sleep.

They used a joystick to navigate through one of two unique, computer-generated 3D spatial mazes.

The researchers found that when sleep was disrupted by sleep apnea, the participants took four percent longer to complete the maze tests.

The study appeared in the Journal of Neuroscience.