Effects of Age on Long-term Memory: Retention of Fixed Interval Responding

Abstract

Retention of the FI scallop was studied in 6-, 12-, and 26-month-old albino rats. The rats were trained over an 8 day period to bar press for food reinforcement on an FI 60 sec schedule. A 16 day retention interval followed acquisition. The retention test consisted of a single 60 min session identical to the acquisition phase. The results showed that while the bar press response was retained by all age groups, the older, 26-month-old rats forgot not to bar press immediately following reinforcement. The FI scallop of the 26-month-old rats was considerably flatter than that of the 6-month-old group and was significantly different from their performance on the last day of acquisition. It was argued that the failure of the 26-month-old rats to produce the appropriate pattern of bar pressing may have been due to the relative paucity of external retrieval cues relevant to recall of the pattern of responding established during acquisition.