Ever feel anxious when you’re not around your iPhone at school or at work? That separation anxiety might be impacting your cognitive abilities, a recent study found.

Researchers discovered that iPhone users solving a series of puzzles performed better when they had their iPhones with them, according to a Thursday statement by the University of Missouri. When deprived of their iPhones, the study’s participants experienced significant physical changes — elevated heart rate, blood pressure and anxiety — alongside poorer cognitive performance.

There’s very little research on the effects of cell phone separation, according to the study, which was published in Journal of Computer-Mediated Communication. But the researchers’ recommendation isn’t to kick your cell-phone checking habit — instead, they suggest iPhone lovers should avoid separating themselves from their phones if they’re taking tests, attending meetings or during other activities that require a great deal of attention.

“The results from our study suggest that iPhones are capable of becoming an extension of our selves such that when separated, we experience a lessening of ‘self’ and a negative physiological state,” Russell Clayton, the study’s lead author, said in the statement.

Read next: Men Who Share Selfies Online Show More Signs of Psychopathy, Study Says

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