LIST ITEM MEMORY IN RATS - EFFECTS OF DELAY AND DELAY TASK

The Serial Position Effect (SPE) was studied in rats using 2 manipulat ions analogous to those that have been shown to decrease the recency e ffect but leave the primacy effect intact in human Ss. In Pall 1, dela ys (5 s to 60 s) were imposed between exposure to a sequence of arms p resented in a 12-arm radial maze and a subsequent test phase. In Part 2, the effect of free access to food in a short (10-s) delay was exami ned. The results from Parts 1 and 2 showed that the primacy and recenc y effects were differentially sensitive to the delay and events within it. In particular the recency effect was found to be more sensitive t o disruption from these sources. The present demonstration of a reduct ion in recency with procedures analogous to those used with humans ext ends the evidence, suggesting that the SPE obtained in rats and humans is a similar phenomenon.