In-vehicle navigation devices are all the rage for looking up addresses and receiving directions as you drive. Most people know that operating these devices while driving is distracting, but exactly how distracting are they? You might want to think twice before touching that dial, according to research by David Kidd.
The George Mason University cognitive psychology and human factors graduate student is conducting two studies on how distractions in the visual field can divert a driver's attention using a full-motion driving simulator.
In Kidd's first study, a participant virtually cruises down a highway in a simulator with panoramic video screens, while the simulator bumps and jostles to feel like a real drive. After a set amount of time, the screen begins to flash between the normal view and a blank screen every couple of seconds, representing someone taking their eyes off the road to consult a map. After a few flashes, suddenly the normal view reveals that the driver has veered into a different lane. Kidd then measures how quickly it takes the driver to correct the car's direction and get it back into the original lane. Early analysis indicates that people whose vision is interrupted before they veer take longer to get back in the correct lane than people whose eyes were on the road when they veered off.
Kidd's second study, which is in the programming stage, will require drivers to observe a pedestrian on the side of the road, note what color shirt he or she is wearing, and then respond to a stoplight turning yellow. This mirrors real-life scenarios in which drivers are constantly distracted by their surroundings but have to make split-second driving decisions at the same time, he says.
His research provides lessons he implements in an even bigger lab: real life.
"I am constantly thinking about the effects my non-driving-related behavior will have on my ability to react," Kidd says. "For example, I am less willing to accept cellphone calls while driving, or I will wait the extra five or 10 seconds to change the radio station on a straight road and avoid doing so during a corner."
Putting attention on the map
People often compare the brain to a computer, but who knew it came with MapQuest? Princeton University psychology graduate student Sara Szczepanski is exploring how people's visual perception and attention maps onto the brain--literally pinpointing parts of the brain that correspond to points in space.
Szczepanski recently completed a two-part experiment designed to isolate the neural underpinnings of spatial orientation using fMRI. First, she had participants focus on a target in the middle of a computer screen while a dot flashed briefly in their periphery. She instructed them not to look at the dot but to remember its location. Then, three seconds later, participants looked toward where the dot had flashed. Szczepanski found that eight different locations in the frontal and parietal cortices corresponded with the eight locations of the dots.
"There was a traveling wave of activity across the cortex," Szczepanski says.
A second task captured which parts of the brain correspond to attentional cues rather than sensory ones. Participants fixated on a series of flashing letters in the middle of the screen while colorful images popped up in the periphery. First, Szczepanski told participants to ignore the peripheral images and to click a button each time an "A," "B," or "C" appeared on the screen. Then she told them to ignore the letters (but still fixate on that point) and instead click the button when a certain target image appeared in the periphery.
By comparing the fMRI scans from the periphery-focused and the periphery-ignoring tasks, Szczepanski located which parts of the brain participants used during attention, identifying the "control center" areas in the frontal and parietal cortices. She then overlaid the results with the topographic maps from the earlier test. Places where the brain activations overlap, Szczepanski says, indicate where in the brain visual-spatial attention is controlled. Next, Szczepanski will look at people's brain activations when they attend to a point in space without any visual stimuli. Ultimately, she says, the goal is to figure out exactly what each region of the brain is doing when paying attention to objects in the visual field. Such research holds promise for better understanding and treating people with attentional impairments due to brain damage.
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