Throughout the ages, the multi-armed Hindu Goddess Durga has gracefully exemplified the concept of “multitasking.” But no mere mortal has the abilities of a powerful divinity with ten arms and three eyes. Humans just don’t multitask well.

A study by King’s College London University found that multitasking – such as allowing frequent email interruptions while you work – can reduce your IQ by 10 points.

DING… DING… DING…

We’ve all experienced the sound of emails hitting our inbox, and the irresistible urge to stop what we’re doing and check each one.

To put it in perspective a 10-point multitasking IQ loss is the same as what happens when you experience sleep deprivation after being forced to stay up all night. Heck, you only experience a four-point decrease in IQ after smoking marijuana! (Which is still huge.)

In fact, if you were to suffer a 20-point IQ decrease you would be considered mentally disabled. So when you multitask, you are halfway there.

We are often tempted to perform many tasks at once. Some of us simultaneously talk on cell-phones while skimming email and listening to music or watching CNN.

Texting while driving has actually killed thousands, prompting Oprah Winfrey to start a “No Phone Zone” pledge drive to discourage this deadly habit.

When it comes to performing serious work, my rule is that the multitasking stops. I even urge students avoid listening to music while studying. Why? Because as far as our brain is concerned, listening to music amounts to a “task.” This means memorization and understanding take longer with music or any kind of sound in the background. So yes, even classical music or other low-key “background” music should be switched off if you are studying.

Your time is precious and you are simply wasting it if you don’t study in total silence.

But don’t just take my word for it. “When we’re multi-tasking, we don’t focus our attention, so information never gets into our memory stores,” says Dr. Gary Small, a memory specialist at UCLA. “We just never learned the information to begin with.” NBC News correspondent Dr. Bruce Hensel agrees, noting that “research shows multi-tasking uses too many parts of the brain at once… Memory and focus areas may not light up on brain maps as much. The stress also may shrink memory receptors.”

Okay, okay… I suppose you do have the occasional exception. Take U.S. snowboarder Hannah Teter, who listened to her iPod as she was winning her gold medal. (She says she was listening to her boyfriend’s rock band while whizzing up and down the half-pipe.)

But you probably won’t win any gold medals in Biochemistry by listening to Lady Gaga during the final exam.

Be a friend to yourself and be in the moment when you study. Whatever you do, focus on doing it well. “One thing at a time” is usually the right approach in school and in life.