It’s pretty common knowledge that proper sleep is key to maintaining cognitive and psychological health. 99 out of 100 people will tell you that, but can they tell why or what to do about it if you’re not getting proper sleep?

Countless studies will prove how good sleep can positively affect your health – improved immune system, reduced stress, decreased chances of diabetes and heart disease, weight loss, and so on. Conversely, poor sleep will negatively affect your health, but how so?

Researchers at Michigan State University’s Sleep and Learning Lab, in findings featured in Journal of Experimental Psychology: General, show that sleep loss has an important effect not just on how well we can maintain our focus, but also on how well we can follow complex procedures — an aspect that they refer to as “placekeeping.”

“Our research showed that sleep deprivation doubles the odds of making placekeeping errors and triples the number of lapses in attention, which is startling,” says study co-author Kimberly Fenn.

“Sleep deprived individuals need to exercise caution in absolutely everything that they do and simply can’t trust that they won’t make costly errors. Oftentimes — like when behind the wheel of a car — these errors can have tragic consequences,” she warns.

“Our findings debunk a common theory that suggests that attention is the only cognitive function affected by sleep deprivation,” says first author Michelle Stepan.