BBC Search Candidate Talk - "The mnemonic scaffold: encoding and retrieving representations across the lifespan"
Our records of experience – memories – make us who we are, and influence the way we process new information. As we get older, our memories may weaken or be lost altogether, underscoring the importance of understanding how we learn and remember. However, memory is a complex cognitive and neural phenomenon, defying any single definition or mechanism. An understanding of how memories work depends on an understanding of the way different aspects of experiences are encoded and retrieved. In this talk, I will present a series of studies aimed at understanding how two cortico-hippocampal networks may provide distinct coding schemes for building a rich representation of an event or experience. An anterior-temporal (AT) network of brain regions represents item/object information, and a posterior-medial (PM) network represents contextual/spatial information in both highly controlled experiments with simple stimuli, as well as naturalistic movie viewing. I will additionally describe a line of research aimed at understanding how these two networks may be uniquely vulnerable in healthy and pathological aging. The AT network shows dramatic vulnerability in object-based discrimination tasks in aging, whereas the PM network shows more subtle vulnerability during perception of meaningful transitions in a film (i.e., event boundaries). Together, these studies provide insight into a representational scaffold used by the brain in encoding and retrieving experiences, and how pieces of this scaffold may break down as we age. I will conclude with an overview of future directions and planned experiments.