Your cognitive capacity is noticibly reduced when your smartphone is within reach — even if it’s off. That’s the takeaway finding from a new study from the McCombs School of Business at UT Austin.
Assistant Professor Adrian Ward and co-authors conducted experiments with nearly 800 smartphone users to measure 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 participants to sit at a computer and take a series of tests that required full concentration. Phones were placed in silent mode, and participants were randomly instructed to place their phones either on the desk face down, in their pocket or bag, or in another room.
The researchers found that those with their phones in another room significantly outperformed those with their phones on the desk, and slightly outperformed those with phones in a pocket or bag.
The findings suggest that the mere presence of a smartphone reduces available brain functioning, even though people feel they’re giving their full attention and focus to the task at hand.
“We see a trend that suggests as the smartphone becomes more noticeable, participants’ available cognitive capacity decreases,” Ward says. “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.”