Kanaka Rajan

Kanaka Rajan, PhD

Associate Professor of Neurobiology, Harvard Medical School

NeuroAI: Using Experimental Data and Computational Models to Reveal the Operating Principles of a Biological Brain

We are a computational neuroscience lab where we bring together the fields of brain research and artificial intelligence/machine learning to figure out how the brain works. We use mathematical and computational models based on data collected from neuroscience experiments to design an artificial system that can perform realistic behaviors using only the machinery the biological nervous system has access to (i.e., neurons and synapses operating at a fast timescale). We build such systems and then we ‘reverse engineer’ them to reveal the operating principles of the real brain.

Our work is unified by the question of how slow cognitive processes such as learning, remembering, and deciding are accomplished by the cooperative activity of neurons and synapses working at a much faster time scale. Connecting neural network theory, artificial intelligence/machine learning, and experimental data analysis, we theorize how this gap in time scales is bridged by neural circuits in the brain. Although designed to use only the biophysical properties of synapses and neurons that form the nervous system, the models we build have the power to extend beyond the details of a single experiment, task, or brain region. They reveal unexpected design principles of the real brain, particularly the mechanisms and features that are responsible for producing or mediating many time-varying behaviors.

Our integrative theories and models can transform the way we study the brain, by making specific, quantifiable predictions that lead to new experiments and drive new hypotheses about how the brain works.

Publications View
Task-Dependent Changes in the Large-Scale Dynamics and Necessity of Cortical Regions.
Authors: Authors: Pinto L, Rajan K, DePasquale B, Thiberge SY, Tank DW, Brody CD.
Neuron
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How to study the neural mechanisms of multiple tasks.
Authors: Authors: Yang GR, Cole MW, Rajan K.
Curr Opin Behav Sci
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Neuronal Dynamics Regulating Brain and Behavioral State Transitions.
Authors: Authors: Andalman AS, Burns VM, Lovett-Barron M, Broxton M, Poole B, Yang SJ, Grosenick L, Lerner TN, Chen R, Benster T, Mourrain P, Levoy M, Rajan K, Deisseroth K.
Cell
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Spike-timing-dependent ensemble encoding by non-classically responsive cortical neurons.
Authors: Authors: Insanally MN, Carcea I, Field RE, Rodgers CC, DePasquale B, Rajan K, DeWeese MR, Albanna BF, Froemke RC.
Elife
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full-FORCE: A target-based method for training recurrent networks.
Authors: Authors: DePasquale B, Cueva CJ, Rajan K, Escola GS, Abbott LF.
PLoS One
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Recurrent Network Models of Sequence Generation and Memory.
Authors: Authors: Rajan K, Harvey CD, Tank DW.
Neuron
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Learning quadratic receptive fields from neural responses to natural stimuli.
Authors: Authors: Rajan K, Marre O, Tkacik G.
Neural Comput
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Maximally informative "stimulus energies" in the analysis of neural responses to natural signals.
Authors: Authors: Rajan K, Bialek W.
PLoS One
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Stimulus-dependent suppression of chaos in recurrent neural networks.
Authors: Authors: Rajan K, Abbott LF, Sompolinsky H.
Phys Rev E Stat Nonlin Soft Matter Phys
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Temperature-compensated chemical reactions.
Authors: Authors: Rajan K, Abbott LF.
Phys Rev E Stat Nonlin Soft Matter Phys
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