In order to determine the stability of the context shift effect over t
ime, rats were trained in a passive avoidance task and tested at four
different intervals afterward. Half of the subjects at each interval w
ere tested for retention of the avoidance response in the context in w
hich they were trained; the other half were tested in a different one.
Rats tested in the different context at 1 and 21 days following learn
ing showed the context shift effect, while those tested at 7 and 14 da
ys-did not. These results indicate that the context shift effect may b
e a phenomenon that changes over time. (C) 1998 Academic Press.