BI 127 Tomás Ryan: Memory, Instinct, and Forgetting

Support the show to get full episodes, full archive, and join the Discord community. Tomás and I discuss his research and ideas on how memories are encoded (the engram), the role of forgetting, and the overlapping mechanisms of memory and instinct. Tomás uses otpogenetics and other techniques to label and control neurons involved in learning and memory, and has shown that forgotten memories can be restored by stimulating "engram cells" originally associated with the forgotten memory. This line of research has led Tomás to think forgetting might be a learning mechanism itself, a adaption our brains make based on the predictability and affordances of the environment. His work on engrams has also led Tomás to think our instincts (ingrams) may share the same mechanism of our memories (engrams), and that memories may transition to instincts across generations. We begin by addressing Randy Gallistel's engram ideas from the previous episode: BI 126 Randy Gallistel: Where Is the Engram? Ryan Lab. Twitter: @TJRyan_77. Related papers Engram cell connectivity: an evolving substrate for information storage. Forgetting as a form of adaptive engram cell plasticity. Memory and Instinct as a Continuum of Information Storage in The Cognitive Neurosciences. The Bandwagon by Claude Shannon. 0:00 - Intro 4:05 - Response to Randy Gallistel 10:45 - Computation in the brain 14:52 - Instinct and memory 19:37 - Dynamics of memory 21:55 - Wiring vs. connection strength plasticity 24:16 - Changing one's mind 33:09 - Optogenetics and memory experiments 47:24 - Forgetting as learning 1:06:35 - Folk psychological terms 1:08:49 - Memory becoming instinct 1:21:49 - Instinct across the lifetime 1:25:52 - Boundaries of memories 1:28:52 - Subjective experience of memory 1:31:58 - Interdisciplinary research 1:37:32 - Communicating science