Proactive transfer and acoustic similarity in short-term paired-assoicate learning

Interference is the most prominent explanation of forgetting in verbal long-term memory (LTM). Interference theory generally holds that forgetting is due to the competition of associations learned during the retention interval rather than to the decay of memory traces. Proactive interference results when the competing associations are learned prior to the criterion associations, and retroactive interference results when the competing associations are learned after the criterion associations. Further explanation of retroactive inhibition (RI) and proactive inhibition (PI) in paired-associate (P-A) learning is found in the extinction hypothesis of interference theory. According to the hypothesis, interference is due to unlearning or extinction of first list or prior learned responses during the learning of second list associations. Barnes and Underwood (1959) gave support to the extinction hypothesis by demonstrating that as the number of trials on the second list increased there was an increase in second list associations and a corresponding decrease in first list associations. With the passage of time, spontaneous recovery of the extinguished first list items occurs, thus explaining the commonly observed increase over time in PI (more interference from the first list) and the decrease in RI (first list responses become more available)