Diazepam and memory: retrograde facilitation produced by interference reduction.

Although diazepam (Valium) reduces learning and memory of information presented after administration (anterograde amnesia), in some cases it improves retention of predrug information (retrograde facilitation). Three experiments examined the magnitude and the conditions for producing retrograde facilitation and tested three hypotheses about the cause of memory enhancement. Differential effort and enhanced consolidation explanations were rejected in favor of a reduced interference interpretation. Improvement in predrug memory occurs because poor postdrug learning reduces the amount of new information available to interfere with prior learning.