"Attention" isn't a binary; it's a gradient from full attention to no attention at all.
"With researchers in the car, the drivers were tested for the extent of their distraction, even as they kept their eyes on the road and hands on the wheel after hitting a voice-command system button. A head-mounted LED light flashed red every three to five seconds at the edge of a driver’s left eye. Drivers pressed a switch attached to a thumb when they saw the light. The researchers measured how voice interactions with a car or smartphone reduced drivers’ reaction times and accuracy at seeing the flashing lights. The drivers also completed surveys about their perceived level of distraction, and videos measured how much of the time they kept their eyes on the road, mirrors or dashboard."
"Attention" isn't a binary; it's a gradient from full attention to no attention at all.
"With researchers in the car, the drivers were tested for the extent of their distraction, even as they kept their eyes on the road and hands on the wheel after hitting a voice-command system button. A head-mounted LED light flashed red every three to five seconds at the edge of a driver’s left eye. Drivers pressed a switch attached to a thumb when they saw the light. The researchers measured how voice interactions with a car or smartphone reduced drivers’ reaction times and accuracy at seeing the flashing lights. The drivers also completed surveys about their perceived level of distraction, and videos measured how much of the time they kept their eyes on the road, mirrors or dashboard."