Memory for non-painful auditory items is influenced by whether they are experienced in a context involving painful electrical stimulation

In this study, we sought to examine the effect of pain on memory. Subjects heard a series of words and made categorization decisions in two different contexts. One context included painful shocks administered just after presentation of some of the words; the other context involved no shocks. For the context that included painful stimulations, every other word was followed by a shock and subjects were informed to expect this pattern. Word lists were repeated three times within each context in randomized order, with different category judgments but consistent pain-word pairings. After a brief delay, recognition memory was assessed. Non-pain words from the pain context were less strongly encoded than non-pain words from the completely pain-free context. An important accompanying finding is that response times to repeated experimental items were slower for non-pain words from the pain context, compared to non-pain words from the completely pain-free context. This demonstrates that the effect of pain on memory may generalize to non-pain items experienced in the same experimental context.