Dr Joshua Koen, University of Texas at Dallas, USA

Abstract

It is well established that episodic memory – memory for unique events – declines as we grow older. Although the evidence that older adults have a reduced capacity to encode new information is compelling, the underlying mechanisms remain poorly understood. I will present data from two lines of research that both examine the relationship between memory encoding and age-related deficits in memory.

The first strand of research takes a traditional approach to examining age differences in memory encoding by examining neural activity elicited in the seconds after a study event is encountered. Specifically, this experiment examines the hypothesis that age-related deficits in memory encoding are related to a reduced capacity to form distinct neural representations of stimulus events, or reduced neural differentiation.

The second strand of research capitalizes on recent research showing that in addition to activity elicited by a study event, neural activity occurring in the seconds before an event is also predictive of successful memory encoding.

The second experiment tests the hypothesis that older adults will show a reduction in these so-called 'pre-stimulus memory effects', which are thought to reflect the engagement of preparatory processes beneficial to memory.

The results demonstrated three main findings: (1) age reduced neural differentiation, (2) neural differentiation was associated with memory performance regardless of age, and (3) older adults showed no evidence for prestimulus memory effects. Together, the studies suggest that the neural processes engaged both before and after an event is experienced contribute to age differences in memory.

Koen, J.D., Borders A.A., Petzold, M.T., & Yonelinas, A.P. (2017). Visual short-term memory for high-resolution associations is impaired in patients with medial temporal lobe damage. Hippocampus, 27 (2), 194-193.

Koen, J.D., & Rugg, M.D. (2016). Memory reactivation predicts resistance to retroactive interference: Evidence from multivariate classification and pattern similarity analyses. Journal of Neuroscience, 36 (15), 4389-4399.

About

Joshua Koen is a research scientist at the University of Texas at Dallas. He is currently a postdoctoral fellow with Dr Michael Rugg, funded by the National Institute of Health and the Dallas Aging Mind Foundation. He received his Bachelor of Science in Psychology at the University of Texas at Arlington in 2003. He then completed his PhD in experimental psychology at the University of California, Davis under the tutelage of Dr Andrew Yonelinas, supported by a Graduate Research Fellowship awarded by the National Science Foundation. His research interests include models of recognition memory, cognitive neuroscience, and cognitive aging.