Ever Have the Phone Ring, Then Forget What You Were Going to Say? Blame it on the Surprise

When was the last time you were about to say something, then the phone rings and you completely forget what it was? If we're talking about me, yesterday.

I couldn't count on both hands all the times that's happened to me lately.  Most would blame it on age but I want to believe it's because I've got so much else in my brain, it crowds other things out.

Now experts are finding that our derailed trains of thought have something to do with the brain’s electrical activity and are offering a new explanation of how that happens.

Researchers at the University of California San Diego, along with Oxford University in the UK,suggest that the same brain system that is involved in interrupting, or stopping, movement in our bodies also interrupts cognition – which, in the example of the phone ringing, derails your train of thought. 

The current study focuses particularly on one part of the brain’s stopping system, a small lens-shaped cluster of densely packed neurons in the midbrain, a portion of the central nervous system associated with vision, hearing, motor control, sleep/wake, arousal (alertness), and temperature regulation. 

Volunteers were given a working memory task. On each trial, they were asked to hold in mind a string of letters, and then tested for recall. Most of the time, while they were maintaining the letters in mind, and before the recall test, they were played a simple, single-frequency tone. On a minority of trials, this sound was replaced by a birdsong segment – which is not startling like a “bang!” but is unexpected and surprising, like a cell phone chirping suddenly. The volunteers’ brain activity was recorded, as well as their accuracy in recalling the letters they’d been shown. 

The results show, the researchers write, that unexpected events manifest the same brain signature as outright stopping of the body. They also recruit the neurons in the midbrain.  And the more these neurons are engaged – or the more that part of the brain responded to the unexpected sound – the more it affected the subjects’ working memory and the more they lost hold of what they were trying to keep in mind, according to newswise.com.

“For now,” says Jan Wessel, one of the researchers, “we’ve shown that unexpected, or surprising, events recruit the same brain system we use to actively stop our actions, which, in turn, appears to influence the degree to which such surprising events affect our ongoing trains of thought.”

“An unexpected event appears to clear out what you were thinking,”  neuroscientist Adam Aron adds. “The radically new idea is that just as the brain’s stopping mechanism is involved in stopping what we’re doing with our bodies, it might also be responsible for interrupting and flushing out our thoughts.”