Poster Session F, Tuesday, March 26, 8:00 – 10:00 am, Pacific Concourse
The relationships between age, fMRI correlates of familiarity and recognition memory performance: Effects of a dual task manipulation
Marianne de Chastelaine1, Erin D Horne1, Michael D Rugg1; 1Center for Vital Longevity and the School of Behavioral and Brain Sciences, The University of Texas at Dallas, USA
We previously described age-invariant relationships between the neural correlates of familiarity and familiarity-driven recognition memory in an associative recognition procedure. Here, young and older participants were scanned while completing an associative recognition test during single and dual task conditions. The test followed a study phase in which word pairs were visually presented in a relational encoding task. Test items comprised studied, rearranged (items studied on different trials) and new pairs. fMRI familiarity effects were operationalized as greater activity for both studied and rearranged pairs identified as ‘rearranged’ than for correctly rejected new pairs. The reverse contrast was employed to identify ‘novelty’ effects. Item memory was lower for the older relative to the younger group. Age-invariant familiarity effects were identified in regions that are often reported as being sensitive to familiarity: medial and lateral parietal cortex, dorsal medial and left lateral prefrontal cortex, and bilateral caudate. These effects positively correlated with estimates of familiarity across participants. Novelty effects were also age-invariant but relatively weak – these effects were identified in ventral mPFC and right TPJ, but not in the MTL as we reported previously. Nevertheless, MTL novelty effects demonstrated an age-invariant relationship with item memory. When entered into the same regression model, familiarity and novelty contrasts independently predicted familiarity strength across participants. Together, these findings largely replicated our previous report. Extending our prior findings, and as expected, the dual task manipulation had a negligible effect on behavioral and neural estimates of familiarity in either age group.
Topic Area: LONG-TERM MEMORY: Development & aging