The invention relates to a processing device for an automatic perception system that involves the use of STN calculation units (1) which receive data from a data bus (7) and which are interconnected by a backannotation bus (6). According to the invention, the units are grouped together in hierarchical sets, in which the set of the order of 0 is formed by a single unit, the set of the order of 1 is formed by the combination of several order 0 set, the sets of the order of P greater than 1 are formed by a combination of lower P-1 order sets, the hierarchised sets of a given order P sharing a backannotation bus. The backannotation buses between a lower order P and a greater order P+1 are interconnected by means of a connection unit. The invention also relates to the method of using the device.