Abbreviated Science Round-up: Seeing memories, citizen science planets, surprise environmental news
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Devices to dredge memories out of the mind and make them visible are a staple of fiction from anime to Black Mirror. For decades, scientists have worked to identify a specific mechanism used to record and recall an individual memory. Is a memory preserved inAbbreviated Science Round-up: Seeing memories, citizen science planets, surprise environmental news
Devices to dredge memories out of the mind and make them visible are a staple of fiction from anime to Black Mirror. For decades, scientists have worked to identify a specific mechanism used to record and recall an individual memory. Is a memory preserved in a single neuron? A collection of connected neurons? Is the ‘engram’ — the permanent storage of the memory — a chemical held at a single location, a somatic change in gene expression, or an electrical state somehow preserved over time? Much of the research has proved frustrating. Efforts to pin down the location of memories have often given what seemed to be definitive results … only to see those results evaporate in the face of additional data. But there’s a new generation of memory research that’s progressing rapidly. Making that progress took letting go of the long-held idea that there was a dedicated part of the brain playing hard drive, acting as storage to the rest of the mind. Writing in Nature, Helen Shen recounts the research of Johns Hopkin’s researcher Janice Chen. Memory, it turns out, is a highly distributed process, not relegated to any one region of the brain. And different types of memory involve different sets of areas. Many structures that are important for memory encoding and retrieval, such as the hippocampus, lie outside the cortex — and Lashley largely missed them. Most neuroscientists now believe that a given experience causes a subset of cells across these regions to fire, change their gene expression, form new connections, and alter the strength of existing ones — changes that collectively store a memory. Recollection, according to current theories, occurs when these neurons fire again and replay the activity patterns associated with past experience. As an example, Chen had people watch a scene from the television series Sherlock. Then she had people recount that scene. Even though people used different words to describe what they had seen, and even though the scene — one in which a shy medical examiner tentatively flirts with Holmes while a body lies between them — made different impressions on people, Chen was able to see the same brain activity pattern behind those thoughts. Advances in brain imaging that allow researchers to track real time activity in fine detail have made these patterns easier to detect and more definitive to trace. The work represents a dramatic departure from previous memory research, which identified more general locations and mechanisms. Chen’s original article is also available. What neither piece makes clear is: Would Chen’s pattern-search reveal whether someone had watched Molly Hooper try to get Sherlock’s attention even if they were not recounting their impression of the scene? If it could, that would bring the research frighteningly close to the Chiclet-sized device from “Crocodile,” which like many episodes of Black Mirror, already seems not that far away. And neither Chen nor Shen indicates whether it would be possible to impose one of these patterns in the mind of someone who didn’t have the original experience, effectively inserting a memory. In any case, research around memory and consciousness continues to be one of the most fascinating areas out there. Because of course it is. If we genuinely grasped the mechanisms of how memory works and how self arises, just that understanding would go a long way toward making us fundamentally different people. But … for now, come on inside and see if you can make some memories about this week’s articles. Read more