Theses Doctoral

Memory updating and enhancement across scales of granularity

Thorp, John N.

The memory system is adaptive in so far as it is able to provide the most robust predictions of what will happen next in our environment. Three means through which it can do this are: arbitrating between temporally embedded recollections and generalized knowledge; rescuing remote memories that are learned to be behaviorally relevant; and updating existing memories if they provide invalid predictions of the outside world. Here, I cover three studies that probe these functions in behavior and in the brain.

In Chapter 1, I show how a data-driven parcellation reveals non-linear gradients in measures of signal heterogeneity across the body of the hippocampus, suggesting novel areas of investigation into how the memory system flexibly constructs fine- and coarse-grained memories.

In Chapter 2, I then explore how memories might be rescued by later aversive experiences, finding novel evidence that the online inferences participants make as to what current stimuli are relevant to their arousal subtly shapes what previous stimuli they retroactively maintain in memory.

Finally, in Chapter 3, I show that signals from the ventral tegmental area modulate the effect of replaying memories on the eventual updating of those memories. Each of these provides novel pieces of evidence into the neural and behavioral markers of how memories are constructed, strengthened, or updated in the brain.


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More About This Work

Academic Units
Thesis Advisors
Davachi, Lila
Ph.D., Columbia University
Published Here
May 22, 2024