Neuro-Informatics seminars
December 2021
Finding needles in the neural haystack: unsupervised analyses of noisy data
Marine Schimel, Kris Jensen· University of Cambridge, Department of Engineering
Wed, Dec 1 · 16:00 UTC · Online
In modern neuroscience, we often want to extract information from recordings of many neurons in the brain. Unfortunately, the activity of individual neurons is very noisy, making it difficult to relate to cognition and behavior. Thankfully, we can use the correlations across time and neurons to denoise the data we record. In particular, using recent advances in machine learning, we can build models which harness this structure in the data to extract more interpretable signals. In this talk, we present two such methods as well as examples of how they can help us gain further insights into the neural underpinnings of behavior.
September 2021
Strong and weak principles of neural dimension reduction
Mark Humphries· School of Psychology, University of Nottingham
Recorded
Large-scale, single neuron resolution recordings are inherently high-dimensional, with as many dimensions as neurons. To make sense of them, for many the answer is: reduce the number of dimensions. In this talk I argue we can distinguish weak and strong principles of neural dimension reduction. The weak principle is that dimension reduction is a convenient tool for making sense of complex neural data. The strong principle is that dimension reduction moves us closer to how neural circuits actually operate and compute. Elucidating these principles is crucial, for which we subscribe to provides radically different interpretations of the same dimension reduction techniques applied to the same data. I outline experimental evidence for each principle, but illustrate how we could make either the weak or strong principles appear to be true based on innocuous looking analysis decisions. These insights suggest arguments over low and high-dimensional neural activity need better constraints from both experiment and theory.
Video · 58 minComputational NeuroscienceNeuroscienceSeries: Sydney Systems Neuroscience and Complexity SNAC
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