The noise of the quantized electromagnetic (EM) field engenders a range of  fascinating phenomena -- from atomic spontaneous emission to Casimir forces. Similar to a pollen grain in the noisy environment of fluid molecules exhibiting random walk, a polarizable particle interacting with the fluctuations of the EM field experiences Brownian motion as it scatters virtual and thermal photons. Classically, the momentum imparted by the field fluctuations on the particle causes a momentum diffusion and drag experienced by its center-of-mass. When considering the dynamics of the quantized center-of-mass of the particle, these very fluctuations gain information about the particle's  position, decohering its center-of-mass in the position basis, and dissipating energy. While the momentum diffusion and thermal drag for the classical center-of-mass are related by the fluctuation-dissipation relation, similar to the the decoherence and dissipation for the quantized center-of-mass -- in this talk we will demonstrate and discuss the connections between classical center-of-mass momentum diffusion and quantized center-of-mass decoherence rates. Our results illustrate a correspondence between classical and quantum Brownian motion of general  polarizable particles, induced by fluctuations of the electromagnetic field.