Simultaneous and separable latent encoding of arm movement direction and kinematics in motor cortex
Little is known about if and how multiple features of movement are simultaneously encoded by population activity in motor cortex. Using neural activity from dorsal premotor cortex (PMd) and motor cortex (M1) as monkeys performed a sequential arm movement task, in this talk I will show that the direction and kinematics of arm movements are simultaneously but separably encoded in the low-dimensional trajectories of population activity. Trajectories of population activity encoded the direction of arm movement, with the distances between neural trajectories proportional to the difference in angle between the directions they encoded. By contrast, different durations of arm movements in the same direction were encoded by how long the neural trajectory took to traverse. A recurrent neural network (RNN) model of our results suggested the direction and duration could be independently controlled by respectively rotating the inputs to motor cortex and scaling the effective neuron time constant within motor cortex. Our results propose a mechanism for the simultaneous yet independent control of multiple arm movement features by motor cortex.
Date: 29 March 2023, 13:00 (Wednesday, 11th week, Hilary 2023)
Venue: Pharmacology, off Mansfield Road OX1 3QT
Venue Details: Lecture Theatre
Speaker: Professor Mark Humphries (University of Notthingham)
Organising department: Nuffield Department of Clinical Neurosciences
Organiser: Dr Rafal Bogacz (University of Oxford)
Organiser contact email address:
Host: Thijs van der Plas (University of Oxford)
Booking required?: Not required
Audience: Members of the University only
Editor: Jacqueline Pumphrey