This article is from Racecar Engineering.
the driver hits the brake it is not just the carbon brake discs and
pads that slows the car down on a 2014 car, the energy recover system
also does a significant amount too, rather like engine braking but a
much stronger effect. This means that the drivers left pedal (F1 cars
have no clutch pedal) is no longer linked directly to the rear brakes
instead it is linked to a computer which then controls the rear brakes.
The front brakes continue to operate in the same way as they always have