| A key feature of human memory is the ability to remember not only discrete pieces of information but also to form novel associations between them. A special type of association, called an "integration", can be formed when the pieces are encoded as a single representation in memory (Wollen, Weber & Lowry, 1972; Murray & Kensinger, 2012). The work presented here investigates what neural mechanisms underlie the formation and subsequent retrieval of integrated mental images in younger adulthood (individuals aged 18-30), whether those mechanisms differ based on the emotional content of the integration, and whether older and younger adults generate and remember emotional integrations differently from one another. I show that younger adults utilize two different routes to form integrations, depending on their emotional content: a rapid, perceptually-supported route that allows for fast integration of emotional pairs but that leads to poor downstream memory for the associates, and a slow, conceptually-supported route for neutral pairs that takes more time but that leads to strong downstream memory. Conversely, older adults utilize slow, controlled processing of emotional integrations that leads to strong memory, but they fail to produce durable memory for non-emotional pairs due to age-related associative deficits. Together, these results highlight differences both within and between age groups in the formation and retrieval of emotional and non-emotional integrations, and suggest a circumstance---integration of emotional pairs---in which older adults can overcome previously reported age-related deficits. |
