During the Saturation Chamber sequence, Famke Jansen is shown as a little girl bouncing first a ball, then a severed head. This is a reference to Fellini's Toby Dammit sequence in Spirits of the Dead.
In the Fellini segment the poster for Roman Polanski's Cul-De-Sac is glimpsed in the reflection upon the car window as Toby Dammit is driven through Rome.