WASHINGTON -- Pedestrians along a short stretch of sidewalk in the nation's capital are being confronted with a choice.
"No cellphones," says lettering on one side.
"Cellphones," says the other lane. "Walk at your own risk."
A National Geographic Channel spokesman acknowledged Thursday that the network was behind the temporary signage, which ran for about a block on the city's 18th street.
The spokesman says pedestrians' reactions are being filmed for a new television series called "Mind Over Masses."
He declined to discuss the experiment taking place.
A filming notice on a city website said the new science show uses "what we know about human behavior" to create fun and "interactive solutions to everyday problems."