Hippocampal lesions do not alter the partial punishment effect.

Rats were trained to run in an alley for food reward. In a 'partial punishment' condition the animals also received occasional footshock in the goalbox; controls received only food reward during training. In a test phase all animals were given both food and footshock in the goalbox on every trial. Previously partially punished animals demonstrated greater persistence in running to the goal during this test phase. This 'partial punishment effect' was unchanged by hippocampectomy whether the experiment was conducted with an inter-trial interval of a few minutes or one of 24 h. The presence of the partial punishment effect in hippocampectomised rats is in sharp contrast with the abolition of the partial reinforcement extinction effect (which is very similar to the partial punishment effect, but based upon nonreward rather than punishment) previously reported after hippocampectomy.