A diner has lunch alone at Bourbon Steak. (Sarah L. Voisin/THE WASHINGTON POST)

Heather E. Henderson sat down for lunch one recent afternoon at Bourbon Steak, the Georgetown Four Seasons restaurant where she’s a regular. She ordered raw oysters, Singapore noodles and one of the head bartender’s house-made apple sodas.

Then, she engaged her lunch companion: the iPhone that has commanded — or at least divided — Henderson’s attention on countless eating excursions.

Swipe, tap tap.

Swipe swipe, tap tap tap.

“I’m a multi-tasker,” said Henderson, the 39-year-old co-owner of an event-management company, who was Facebooking and tweeting throughout the meal. “I’m a bit of a foodie, but most of my friends are not. If I limited myself to only going out with physical dining companions, I wouldn’t go out nearly as often as I do.”

Dining out alone? There’s an app for that.

In just about any restaurant these days — even fancier places where the multi-course proffer is something like performance art — you’re likely to find parties of one fiddling with their digital devices. (That’s to say nothing of people texting at the table or otherwise checking their phones when they’re sharing a meal with others, a related, more widely reviled phenomenon.)

The lonely experience of passively reading while waiting for the bread basket has given way to e-mailing or playing Angry Birds before attacking a 28-ounce, dry-aged, butter-poached slab of prime porterhouse ($65 at Bourbon Steak).

“It’s almost rare now that a single diner will walk in without some type of device,” said Mark Politzer, Bourbon Steak’s general manager. “It’s really changed the experience for single diners. It’s less awkward for them, but they’re more engaged in work or whatever else they’re doing on their device than in having a conversation with us or focusing on the meal.”

The development churns some restaurateurs’ stomachs. At Rogue 24 — a theatrical, envelope-pushing Washington restaurant where the chefs work at the center of the 52-seat dining room — proprietor R.J. Cooper has even banned electronic devices. But some diners have gone, well, rogue.

“There’s not a lot we can do,” Cooper said. “They’re paying our bills. Here’s the thing: People are so attached to their . . . smartphones and tablets that they’re going to use them regardless. We’re not cops about it. We can’t make them turn them off.

“I do understand it gives solo diners something to do besides eat. But we have a lot going on. Our dining experience is so interactive. . . . It bothers me if they’re tweeting and Facebooking and not really getting into the experience.”

Politzer is more sanguine. In fact, he went shopping recently for cordless chargers that diners could use at their tables. “Ten years ago, I might have found this appalling, but restaurants have to be open-minded and adjust,” he said. “This is a common practice now, and it isn’t going away.”

Eric Ziebold sees it all the time from his kitchen at City­Zen,his four-star restaurant at the Mandarin Oriental Hotel in Southwest: solo diners with smartphones, tablets, even laptops.

Some put them down when the James Beard Award-winning chef sends pumpkin tournedos and duck bolognese to their tables. Others barely look up.

“If you’re going to keep typing and that’s more important than what you’re eating, then what we’re doing is lost on you anyway,” said Ziebold. “The reality of today’s attention span is some people need constant stimuli. Do I take personal offense to it? No.”

CityZen has embraced the trend by ordering an iPad for parties of one to use at their table. The tablet was deployed for the first time in the dining room last week, complete with Internet access over the hotel’s WiFi network. (All the better to Google photos that reveal the tattoos CityZen’s rock-star sommelier Andy Meyer is hiding under his suit?)

To MIT professor Sherry Turkle, who studies people’s relationships with technology, the proliferation of solo diners focusing on glowing digital companions is more sour than sweet. “Having a solitary meal in a restaurant is a basic spiritual practice,” she said. “It’s a classic way to experience moments of solitude and to refresh and restore and gather yourself.

“Why would we want to go to a restaurant where there’s something to be savored and put ourselves in a state of mind where that goes right over our heads?” she asked. “There is a cost to the pleasures of the moment and a cost to our humanity.”

You say dead zone,
they say oasis

Let us pause here for a restorative palate cleanser: The devices aren’t actually everywhere.

Drive out to Washington, Va., to the Inn at Little Washington, a high temple of American cuisine, and you’re not likely to see any diners — solo or otherwise — checking in on Foursquare.

For one thing, the destination restaurant sits in a rural dead zone for most cell service providers. (Exception: Sprint.)

For another, according to owner-chef Patrick O’Connell, his staff works hard to save guests from digital distractions.

“We’re particularly adept at casting a spell and luring them into participating in something that is riveting,” he said, adding that he couldn’t recall an instance of a diner goofing off on a phone or tablet between courses.

“There’s a tragic quality to the cultural phenomenon that has been happening. People never seem to be present in the space they’re in. It’s a real pleasure to see people thoroughly immersed in where they are when they’re here.”

Yet some top chefs and restaurateurs who are not exactly enamored by the trend do this very thing when they’re eating alone.

“If I’m out by myself, I’ll pull out my iPhone,” said Cathal Armstrong, chef-owner of the acclaimed Old Town Alexandria eatery Restaurant Eve. “If it’s a dark dining room, I tend to keep it below the table, so other people can’t see the light as much. And as soon as the food arrives, I put it away and pay attention to what I’m eating. But I’ll open it back up again and read the news or generally doodle, just wasting time.”

Ashok Bajaj, whose restaurant empire includes the Oval Room, the Bombay Club and Rasika, admits to it as well, even though he holds dear the notion that dining out is an event to be relished and celebrated. “But we’re losing that,” he said. “You see it all the time, people texting and doing all this other stuff while they’re eating.”

For her part, Henderson, the Bourbon Steak regular, said she sometimes does leave her iPhone in her turquoise Akris handbag when she’s dining alone. Certain meals — “at chef-driven restaurants,” for instance — warrant her undivided attention, she said. “I’m not so addicted that I can’t put it away.”

Henderson shrugged as her bowl of curried Singapore noodles got cold.

Of course, she’d already shared it with friends: Before taking a single bite, Henderson had snapped a photo of the dish with her iPhone and posted it online.