“This goes beyond Dick Tracy calling someone with
a cell phone on the wrist.” — MICHAEL MCALPINE
Brain waves assist faster braking
By Laura Sanders
In a fast-moving car, the brain can hit the
brakes faster than the foot. By relying on
brain waves that signal the intent to jam
on the brakes, a new technology could
shave critical milliseconds off the reaction time, researchers report online July
28 in the Journal of Neural Engineering.
In the study, computer scientist Stefan
Haufe of the Berlin Institute of Technology and his colleagues measured brain
wave changes while participants drove in
a car simulator. Participants drove about
60 miles per hour following a lead car on
a curvy road with heavy oncoming traffic.
Every so often the lead car would slam on
its brakes, so that the participants would
have to either do the same or crash.
For most drivers, the lag between the
lead car stopping and slamming on the
brakes was around 700 milliseconds.
Particular neural signatures were evident during this lag time.
Haufe and his colleagues designed a
system that detected and interpreted
these neural patterns.
In computer simulations, the system,
which included data from measures of
leg-muscle electrical activity, performed
about 130 milliseconds faster than an
unaided driver, the team reports. For a car
traveling at 60 miles per hour, this time
difference translates to about 3. 7 meters
of stopping distance — the length of some
At peak performance, the system
would incorrectly slam on the brakes
As part of an effort to develop an automated braking system, researchers
record brain activity from a cap worn by
participants driving in a simulator.
almost two times per hour, a false alarm
rate that needs to come down if the
system is going to be useful, says cognitive neuroscientist Raja Parasuraman of
George Mason University in Fairfax, Va.
“Even a 1 percent false alarm rate would
not be acceptable to most people,” he
September 10, 2011 | SCIENCE NEWS | 11