Age-related changes in resolving proactive interference in associative memory

Abstract

Previous research has found that older adults are more susceptible to proactive interference. This is likely due to age-related deficits in the PFC-mediated cognitive control processes recruited to resolve interference. The current functional magnetic resonance imaging (fMRI) study investigated if age-related deficits in PFC-mediated cognitive control processes underlie age-related differences in the resolution of proactive interference in an associative memory task. Young and older adults were tasked with remembering which associate (face or scene) objects were paired with most recently during study, under conditions of high, low or no proactive interference. Following scanning, participants’ memory was tested for varying levels of episodic detail about the pairings. Young and older adults were similarly susceptible to proactive interference. Memory for both the general target category and the specific target associate worsened as the level of proactive interference increased, with older adults having moderately worse memory for the specific target associate. Across age, the left-VLPFC showed increased recruitment for increasing levels of interference at encoding suggesting that older adults are able to spontaneously engage in post-retrieval selection to the same extent as young adults. At retrieval, older adults recruited the vmPFC more than young adults during remembered low interference trials but similarly recruited the vmPFC during remembered high interference trials. In line with the CRUNCH model, this suggests that older adults need to engage in more monitoring for low interference items, but engage in a similar amount of monitoring to young adults for high interference items, suggesting that successfully resolving high interference is equally difficult for both young and older adults.