Acoustic similarity effects on memory for paired associates

Experiment I tested the short-term retention of paired associates (PAs) with 6-item PA lists and a probe technique. Acoustic similarity between the left-hand members (e.g., LAMPRAMP) of specific pairs increased proactive inhibition but not retroactive inhibition (RI). Experiment II, which used the same kind of materials, examined RI in memory for PAs following multi-trial practice on two consecutive PA lists. Acoustic similarity had no substantial effect on retention of the first list or learning of the second list. These data suggest that, in short-term retention at least, acoustic similarity effects on the memory for PAs are mostly proactive.