Rats were experimented upon during the course of the research that proved that processing memory for context involves the hippocampus, while memory is retained by the anterior cingulate cortex. Memories are consolidated and stored by the amygdala, which is another part of the brain. The research conclusively proves that different parts of the brain are involved in processing the different aspects of a single incident.
This will also serve to explain why different memory systems are affected by different types of strokes, and also understanding why the memory processing activity goes wrong. During the course of the experiment, rats were familiarized with the insides of a box, and later administered a foot shock in a dark part of the box, and the drug oxotremorine was injected into the rat's hippocampus.
Those rats which were administered with this drug remembered the shock they received and stayed away from the part of the box where they received the shock. Those rats which were given the injection after the shock event did not appear to retain the memory of the incident.
Memory retention was even better in the case of the rats which were given the amygdala injections, and there was no difference evident in the case of those which were given the drug before the shock, when compared to after the shock. This proves that the amygdala plays a prominent role in consolidating memories.