Two Out of Three Ain’t Bad

So it’s Monday and perhaps you hit the keyboard needing to get several things done ASAP.  Wouldn’t it be great if you could truly multi-task and really do a bunch of things at the same time? New research on the brain says fuggetaboutit.  It concludes that we’re wired to juggle two things or make a choice between two things but the brain goes haywire if you throw in a third.

Here’s the gist of why multi-tasking should perhaps be called dual-tasking because humans are truly terrible at mentally juggling more than two things.  (From Live Science, with thanks to writer Rachael Rettner) I’ve omitted the cumbersome details on the actual test they carried out because the results pretty much explain it.  It all comes down to the brain’s ability to put a value or reward on each task.  Here’s the story:

When faced with two tasks, a part of the brain known as the medial prefrontal cortex (MFC) divides so that half of the region focuses on one task and the other half on the other task. This division of labour allows a person to keep track of two tasks pretty readily, but if you throw in a third, things get a bit muddled.

“What really the results show is that we can readily divide tasking. We can cook, and at the same time talk on the phone, and switch back and forth between these two activities,” said study researcher Etienne Koechlin of the Université Pierre et Marie Curie in Paris, France. “However, we cannot multitask with more than two tasks.”

The results will be published this week in the journal Science.

The MFC is thought to be part of the brain’s “motivational system.” Specifically, it helps monitor the value of rewards and drives a person’s behavior according to that value. In other words, it’s where rewards are represented in the brain.

The study’s results might also explain why humans seem to have a hard time making decisions between more than two things, Koechlin said.

When faced with three or more choices, subjects don’t appear to evaluate them rationally; they simply start discarding choices until they get back to a binary choice.  This is perhaps because your brain can’t keep track of the rewards involved with more than two choices, Koechlin said.

So there you have it.  I guess it explains why until now I’ve been unable to ride my motorcycle while juggling knives and hemming pants…or something like that.