FURTHER EVIDENCE FOR HIERARCHICAL CHUNKING IN RAT SPATIAL MEMORY

In Experiment 1, rats were given a test to determine the order of pref erence among 3 types of food. Two groups of rats then were trained on a 12-arm radial maze in Experiment 2, with the 3 foods placed in fixed -arm locations for 1 group and in locations that varied randomly acros s sessions for the other group. The results replicated those of Dallal and Meck (1990) by showing faster learning and more clustering of arm choices by food type in the fixed-locations group than in the random- locations group. Two further experiments were performed to test the ch unking hypothesis. Observations of working memory in Experiment 3 and the reorganization of reference memory in Experiment 4 both supported the chunking hypothesis by showing superior spatial memory and arm chu nking by food type when chunk integrity was maintained than when it wa s compromised.