Happy to share my first graduate school paper with @neurojosh, out today in @NatureNeuro (nature.com/articles/s4159…): “Memory retrieval modulates spatial tuning of single neurons in the human entorhinal cortex”. Read on for my best attempt at using twitter effectively (1/7):
@neurojosh @NatureNeuro How do our brains represent individual memories for recall? We approached this question through the lens of spatial representations, asking if spatially-tuned neurons highlight locations relevant for memory retrieval (like dropping a pin in Google Maps for a favorite cafe).
@neurojosh @NatureNeuro We directly recorded single-neuron activity from epilepsy patients with electrodes implanted for clinical treatment. These patients graciously volunteered to perform a spatial memory task in which they learned and then recalled the location of 4 objects in a virtual environment. 
@neurojosh @NatureNeuro We measured the activity of these neurons during memory recall, when the object was no longer visible in the environment. Some neurons behaved much like place cells, activating in the same location no matter what the person was supposed to recall.
@neurojosh @NatureNeuro Others, importantly, seemed to shift their firing to the specific object-location that was cued for recall. We called these “memory-trace” neurons, and we did a lot of work in the paper to show that their activity seems to track the location a person is targeting for retrieval.
@neurojosh @NatureNeuro We found many of these neurons in the entorhinal cortex, and we were able to show that EC memory-trace cell activity distinguished between the distinct object-location memories - even when subjects were not moving! More on this, and a lot more in the paper (so check it out!).
@neurojosh @NatureNeuro Many thanks to my PI @neurojosh, and the many collaborating researchers and institutions that made this possible (especially @IM_Inman!) And many many thanks to the patients that volunteered for this research despite going through the difficulties of epilepsy and hospitalization.
@neurojosh @NatureNeuro @IM_Inman Please reach out if you have any comments/critiques! The EC is an exciting region and I'm sure many have thoughts on the functional importance neurons such as these might have. Or if you have thoughts about funny GIFs I could have used in this tweetstorm.
