Prius revenerative brakeing modulated?

Is Prius Gen III regen braking either ON of OFF or is is MODULATED by varying pressures on the brake pedal? Another way of asking - if I am cruising at highway speed and take my foot off of the accelerator, kinetic energy is clearly converted to electrical energy and stored, resulting in some vehicle slow down (emulating engine compression). Now, if I PRESS LIGHTLY on the brake pedal, just enough so that I can feel in increase in deceleration, has the hybrid system INCREASED THE RATE OF REGENERATIVE BRAKING or simply added mechanical (hydraulic) brakes? If I press a little harder on the brake pedal to slow a little faster, does the rate of regeneration increase? Do the mechanical brake shoes (pucks?) literally NOT ENGAGE AT ALL as long as I keep only light to moderate pressure on the brake pedal (until I slow below 7 mph)?

It's modulated, as far as I know But for a hard or panic stop, the friction brakes activate, even if you are above 7 mph.

Yes it's fully modulated. If you want to know what's going on inside, get a hold of a Scanguage2, shows all the interesting bits going on..

If it wasn't modulated by foot pressure it would feel much more
jerky and abrupt. Watch your HSI and how the "charge" portion
changes as you vary your foot -- that's a fairly reasonable
representation of how much regen current is being sent to your
battery.
.
_H*