probablyasocialecologist:

Prof Earl Miller, a neuroscientist at Massachusetts Institute of Technology, explained one to me. He said “your brain can only produce one or two thoughts” in your conscious mind at once. That’s it. “We’re very, very single-minded.” We have “very limited cognitive capacity”. But we have fallen for an enormous delusion. The average teenager now believes they can follow six forms of media at the same time. When neuroscientists studied this, they found that when people believe they are doing several things at once, they are actually juggling. “They’re switching back and forth. They don’t notice the switching because their brain sort of papers it over to give a seamless experience of consciousness, but what they’re actually doing is switching and reconfiguring their brain moment-to-moment, task-to-task – [and] that comes with a cost.” Imagine, say, you are doing your tax return, and you receive a text, and you look at it – it’s only a glance, taking three seconds – and then you go back to your tax return. In that moment, “your brain has to reconfigure, when it goes from one task to another”, he said. You have to remember what you were doing before, and you have to remember what you thought about it. When this happens, the evidence shows that “your performance drops. You’re slower. All as a result of the switching.”

This is called the “switch-cost effect”. It means that if you check your texts while trying to work, you aren’t only losing the little bursts of time you spend looking at the texts themselves – you are also losing the time it takes to refocus afterwards, which turns out to be a huge amount. For example, one study at the Carnegie Mellon University’s human computer interaction lab took 136 students and got them to sit a test. Some of them had to have their phones switched off, and others had their phones on and received intermittent text messages. The students who received messages performed, on average, 20% worse. It seems to me that almost all of us are currently losing that 20% of our brainpower, almost all the time. Miller told me that as a result we now live in “a perfect storm of cognitive degradation”.