Human Long-Term Memory: Encoding & Retrieval
Based on my personal research interests, I was quite excited to attend this nanosymposium on encoding and retrieval in human memory. Although I tell people that I study sleep and memory, the Paller lab is really a memory lab that somehow wandered into the interesting land of memory consolidation during sleep. Most of my training has focused on the memory aspect which continues to fascinate me to this day, so I was excited to see what new insights I could glean from these talks.
For better or worse though, I had a lunch that ran late and sadly missed the first two talks of the session. However, I was thrilled to hear the rest of the talks.
After staying for the rest of the session, I decided that I have two favorites. The first is “Distinct cortical systems reinstate content and context information during memory search.” This presentation focused on a key element of episodic memory, contextual reinstatement. One of my major complaints with many memory tasks is that they often chose simplistic designs that are easy to test, but don’t match up to real world complexity. I thought the way James Kragel tested memory and then used intracranial recordings to understand the network dynamics of memory reinstatement was a clever way to disentangle semantic and episodic memory.
My second favorite, which is perhaps no surprise considering my background, was titled “Sleep consolidates memory through diverging effects on automatic and cognitive emotional responses in children.” Common wisdom has long shown that naps are an important part of a child’s daily routine. But researcher Katharina Zinke wanted to put such traditions to the test. She & her collaborators tested whether sleep compared to wake helped kids (age 8-11 years) consolidate negative pictures over neutral ones. She tested the children after a 10-hour delay of either sleep or wake and found that sleep did indeed lead to better memory consolidation than wake. Moreover, REM sleep theta power correlated with the preference of negative emotional stimuli over neutral images. Although after sleep, the images were rated as less negative than before sleep or after a period of wake. It’s nice to see science upholding the common sense instructions of our parents. Sleep helps children process memories such that they remember the episode with out the intense emotional baggage from the event itself.