Spatio-temporal control of neural activity through gain modulation in cortical circuit models
Motor cortex (M1) exhibits a rich repertoire of activities to support the generation of complex movements. Although recent neuronal-network models capture many qualitative aspects of M1 dynamics, they can generate only a few distinct movements. Additionally, it is unclear how M1 efficiently controls movements over a wide range of shapes and speeds. We demonstrate that simple modulation of neuronal input–output gains in recurrent neuronal-network models with fixed architecture can dramatically reorganize neuronal activity and thus downstream muscle outputs. Consistent with the observation of diffuse neuromodulatory projections to M1, we show that a relatively small number of modulatory control units provide sufficient flexibility to adjust high-dimensional network activity using a simple reward-based learning rule. Furthermore, it is possible to assemble novel movements from previously learned primitives, and one can separately change movement speed while preserving movement shape. Our results provide a new perspective on the role of modulatory systems in controlling recurrent cortical activity.
Date:
3 May 2019, 15:00 (Friday, 1st week, Trinity 2019)
Venue:
Le Gros Clark Building, off South Parks Road OX1 3QX
Venue Details:
Lecture Theatre
Speaker:
Dr Jake Stroud (University of Cambridge)
Organisers:
Dr Friedemann Zenke (University of Oxford),
Dr Tim Vogels
Part of:
Oxford Neurotheory Forum
Booking required?:
Not required
Audience:
Members of the University only
Editor:
Friedemann Zenke
