title: Coupling Time Decoding and Trajectory Decoding using a Target-Included Model in the Motor Cortex.
abstract: Significant progress has been made within the last decade in motor cortical decoding that predicts movement behaviors from population neuronal activity in the motor cortex. A majority of these decoding methods have focused on estimating a subject's hand trajectory in a continuous movement. We recently proposed a time identification decoding approach and showed that if a stereotyped movement is well represented by a sequence of targets (or landmarks), then the main structure of the movement can be reconstructed by detecting the reaching times at those targets. Both trajectory decoding and landmark-time decoding have their particular advantages, whereas a coupling of these two different strategies has not been examined. In this article we propose a synergy that comes from combining these two approaches for a stereotyped movement under a linear state-space framework. We develop a new decoding procedure based on a forward-backward propagation where the target is used in the initial stage in the backward step. Experimental results show that the new method significantly improves decoding accuracy over the non-target-included models. Furthermore, the coupling based on the new target-included method effectively combines the time decoding and trajectory decoding and further improves the decoding accuracy.
authors.affiliation: Department of Statistics, Florida State University, Tallahassee, FL 32306-4330, USA.
authors.forename: Vernon
authors.initials: V
authors.lastname: Lawhern
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Hatsopoulos
authors.forename: Wei
authors.initials: W
authors.lastname: Wu