The need to have regular human moments at work is similar to the need to stand up and stretch on an airplane: Your well-being depends on it. On top of that, a workday with regular face-to-face contact is more energizing than a day full of contacts exclusively via computer and phone.

So get out from behind your computer and have a "human moment" – a term coined by Harvard lecturer Edward M. Hallowell. He defines the human moment as "an authentic psychological encounter that can happen only when two people share the same physical space."

The human moment is a quality of interaction you don't get from computers, or even the phone. "In order to really converse with someone, you have to keep reading them– when they look at you, when they smile, when they turn away," says Jayme Lewin Rich, an occupational therapist who specializes in treating sensory integration dysfunction. In front of a live person our brains read slews of visual cues every second, and we don't get that opportunity otherwise.

Often the computer encourages superficial attention to streams of data, but talking face-to-face demands focused emotional and intellectual involvement. (This is why, for example, many people with autism love the computer and have little interest in faces.) Visual data about a person is fundamentally different for a brain to process than computer-screen data.

In the article, The Human Moment at Work (subscription) Hallowell presents a wide body of research to show that face-to-face interaction is essential for keeping our brains sharp. For example, deaths are three times higher for socially isolated people than for those with strong connections to others. And researchers at McGill University found that it takes less than a day of no normal contact with the outside world for an adult to start hallucinating.

Even when it's not such drastic circumstances, talking to a live person can give us a surge of energy in the middle of the workday. "In-person contact stimulates an emotional reaction," says Lawrence Honig, a neurologist at Columbia University. Bonding hormones are higher when people are face-to-face. And some scientists think that face-to-face contact stimulates the attention and pleasure neurotransmitter dopamine, and serotonin, a neurotransmitter that reduces fear and worry.

This explains why working at the computer or talking on the phone for a long time is as exhausting as staring at the TV. The brain starts to crave rest from input overload and fuel from human contact.

So when you're feeling tired at work, try creating a human moment for an energy boost. It doesn't have to be earth-shattering and intimate. It can be short and professional. You just need to be paying attention.