A smartphone can lower cognitive capacity significantly even when you are not using it, according to new study by The University of Texas at Austin.
Researchers tested nearly 800 smartphone users in an attempt to measure, for the first time, how well people can complete tasks when they have their smartphones nearby even when they’re not using them.
In one experiment, the researchers asked study participants to sit at a computer and take a series of tests that required full concentration in order to score well. The tests were geared to measure participants’ available cognitive capacity — the brain’s ability to hold and process data at any given time. Before beginning, participants were randomly instructed to place their smartphones either on the desk face down, in their pocket or personal bag, or in another room. All participants were instructed to turn their phones to silent.
The researchers found that participants with their phones in another room significantly outperformed those with their phones on the desk, and they also slightly outperformed those participants who had kept their phones in a pocket or bag.
“We see a linear trend that suggests that as the smartphone becomes more noticeable, participants’ available cognitive capacity decreases,” said coauthor Adrian Ward. “Your conscious mind isn’t thinking about your smartphone, but that process — the process of requiring yourself to not think about something — uses up some of your limited cognitive resources. It’s a brain drain.”
It didn’t matter whether a person’s smartphone was turned on or off, or whether it was lying face up or face down on a desk, the study said. Having a smartphone within sight or within easy reach reduces a person’s ability to focus and perform tasks because part of their brain is actively working to not pick up or use the phone.
“It’s not that participants were distracted because they were getting notifications on their phones,” said Ward. “The mere presence of their smartphone was enough to reduce their cognitive capacity.”