Bernstein Center Freiburg

Bernstein Seminar

July 21, 2020
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Bernstein Seminar
JUAN ÁLVAREZ GALLEGO ►

Neuroscience & Neuropreosthetics Lab | Department of Bioengineering | Imperial College London | UK

A neural population view on how the brain controls behavior

Tuesday, July 21, 2020

17:15h

Zoom Meeting, contact Host for Meeting ID and Password.

Hosted by Carsten Mehring

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Abstract

The analysis of neural population dynamics in several brain cortices has consistently uncovered low-dimensional subspaces that capture a significant fraction of neural variability. These “neural manifolds” are spanned by specific patterns of correlated neural activity, the “neural modes.” I will discuss a model for cortical processing in which the time-dependent activation of these neural modes, rather than the independent modulation of single neurons, controls behavior. I will first focus on how the same neural population in primary motor cortex can cause a rich set of behaviors. Single neuron activity is complex and heterogeneous and varies greatly across different tasks. Yet, the structure and even the temporal activation dynamics of some neural modes is remarkably well preserved across these different behaviors. Animals readily execute learned behaviors in a consistent manner. How does cortex achieve this stable control? We recorded from neural populations in premotor, primary motor, and somatosensory cortices for up to two years as monkeys performed the same task. Intriguingly, despite steady turnover in the recorded neurons, the activation dynamics of the neural modes remained stable. Such stability allowed reliable decoding of behavioral features for the entire timespan, while fixed decoders based on the recorded neural activity degraded substantially. Whether viewed across time or across tasks, cortex may thus generate behavior in a consistent manner through the flexible activation of combinations of neural modes, which themselves may arise from network connectivity. Given that neural modes are found throughout the brain, from prefrontal to visual and olfactory cortices, and even hippocampus, similar mechanisms may allow other areas to perform non-motor functions.

Selected publications

J.A. Gallego, M.G. Perich1, R.H. Chowdhury, S.A. Solla, L.E. Miller. Long-term stability of cortical population dynamics underlying consistent behaviour. Nature Neuroscience 23:260-276, 2020.
M.G. Perich, J.A. Gallego, L.E. Miller. A neural population mechanism for learning. Neuron 100(4):964-976, 2018.
J.A. Gallego, M.G. Perich, S.N. Naufel, C. Ethier, S.A. Solla, L.E. Miller. Cortical population activity within a preserved neural manifold underlies multiple motor behaviors. Nature Communications, 9:4233, 2018.
J.A. Gallego, M.G. Perich, L.E. Miller, S.A. Solla. Neural manifolds for the control of movement. Neuron 94(5):978–84, 2017
C. Ethier1, J.A. Gallego1, L.E. Miller. Brain-controlled neuromuscular stimulation to drive neural plasticity and enhance recovery. Current Opinion in Neurobiology 33:95–102, 2015

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