BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250628T041522EDT-1602ovxF43@132.216.98.100 DTSTAMP:20250628T081522Z DESCRIPTION:Making sense of large-scale neural and behavioral data\n\nCarse n Stringer\, Howard Hughes Medical Institute\n Tuesday October 3\, 12-1pm\n Zoom Link: https://mcgill.zoom.us/j/86855481591\n In Person: 550 Sherbrooke \, Room 189\n \n Abstract: Advances in protein engineering and microscopy ha ve enabled routine recordings of over 50\,000 neurons simultaneously in th e mouse cortex at a sampling rate of 3Hz\, or ~8\,000 neurons at a rate of 30Hz. What properties does this large-scale activity have? One popular hy pothesis is that this neural activity is “simple” and low-dimensional\, an d we can summarize even 50\,000 neuron recordings with just a few numbers at any one time. Many analytical tools and theories have been developed ba sed on this assumption. However\, in our large-scale recordings we found t hat neural responses to visual stimuli were high-dimensional\, exploring m any diverse patterns of activity that could not be reduced to a few number s. This high-dimensional structure that cannot be easily captured by exist ing data visualization methods. We therefore developed an embedding algori thm called Rastermap\, which captures complex temporal and highly nonlinea r relationships between neurons\, and provides useful visualizations by as signing each neuron to a location in the embedding space. We found within neural datasets from virtual reality tasks unique subpopulations of neuron s encoding abstract elements of decision-making\, the environment and beha vioral states. Further\, we found that ongoing “spontaneous” activity in c ortex was high-dimensional\, representing the moment-to-moment behaviors o f the mouse. To interrogate behavioral representations in the mouse brain\ , we developed the fast Facemap network for tracking 13 distinct points on the mouse face recorded from arbitrary camera angles. We used Facemap to find that the neuronal activity clusters which were highly driven by behav iors were more spatially spread-out across cortex. We also found that the deep keypoint features inferred by the model had time-asymmetrical state d ynamics that were not apparent in the raw keypoint data. In summary\, Face map provides a stepping stone towards understanding the function of the br ainwide neural signals and their relation to behavior.\n DTSTART:20231003T160000Z DTEND:20231003T170000Z SUMMARY:QLS Seminar Series - Carsen Stringer URL:/qls/channels/event/qls-seminar-series-carsen-stri nger-350907 END:VEVENT END:VCALENDAR