Effects of hypoxia on memory consolidation: Implications for a multistage model of memory

Anoxia treatment given 2.5 or 5 min after a single trial passive avoidance task in day-old chicks yielded a temporary retention loss between 20 and 50 min after learning. No effect was obtained when the treatment was administered immediately or 10 min after learning. The temporary retention deficit was not due to a generalized retrieval loss since anoxia given at various times after 10 min following learning with retention tested 30 or 60 min after anoxia treatment, did not yield a retention deficit. Similar findings were obtained with hypoxia. The implications of the results for a multistage model of memory were examined. In particular, it was suggested that the temporary retention deficit may be due to the breakdown of retrieval mechanisms associated with the second stage in a 3-stage model of memory processing.