Poster E60, Monday, March 26, 2:30-4:30 pm, Exhibit Hall C
Human aging reduces the neurobehavioral influence of motivation on episodic memory
Maiya Geddes1,2, Aaron T. Mattfeld2,3, Carlo de los Angeles2, Anisha Keshavan2,4,5, John D. E. Gabrieli2; 1Brigham and Women’s Hospital, Division of Cognitive and Behavioral Neurology, Harvard Medical School, Boston, MA, USA, 2Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA, 3Florida International University, Miami, FL, USA, 4Department of Neurology, University of California, San Francisco, 5Bioengineering Graduate Group, University of California, San Francisco and Berkeley
The neural circuitry mediating the influence of motivation on long-term declarative or episodic memory formation is delineated in young adults, but its status is unknown in healthy aging. We examined the effect of reward and punishment anticipation on intentional declarative memory formation for words using an event-related functional magnetic resonance imaging (fMRI) monetary incentive encoding task in twenty-one younger and nineteen older adults. At 24-hour memory retrieval testing, younger adults were significantly more likely to remember words associated with motivational cues than neutral cues. Motivational enhancement of memory in younger adults occurred only for recollection (“remember” responses) and not for familiarity (“familiar” responses). Older adults had overall diminished memory and did not show memory gains in association with motivational cues. Memory encoding associated with monetary rewards or punishments activated motivational (substantia nigra/ventral tegmental area) and memory-related (hippocampus) brain regions in younger, but not older, adults during the target word periods. In contrast, older and younger adults showed similar activation of these brain regions during the anticipatory motivational cue interval. In a separate monetary incentive delay task that did not require learning, we found evidence for relatively preserved midbrain and striatal reward anticipation in older adults. This supports a potential dissociation between incidental and intentional motivational processes in healthy aging. The finding that motivation to obtain rewards and avoid punishments had reduced behavioral and neural influence on intentional episodic memory formation in older compared to younger adults is relevant to life-span theories of cognitive aging including the dopaminergic vulnerability hypothesis.
Topic Area: LONG-TERM MEMORY: Development & aging