title: Multistep model for predicting upper-limb 3D isometric force application from pre-movement electrocorticographic features.
abstract: Neural correlates of movement planning onset and direction may be present in human electrocorticography in the signal dynamics of both motor and non-motor cortical regions. We use a three-stage model of jPCA reduced-rank hidden Markov model (jPCA-RR-HMM), regularized shrunken-centroid discriminant analysis (RDA), and LASSO regression to extract direction-sensitive planning information and movement onset in an upper-limb 3D isometric force task in a human subject. This mode achieves a relatively high true positive force-onset prediction rate of 60% within 250ms, and an above-chance 36% accuracy (17% chance) in predicting one of six planned 3D directions of isometric force using pre-movement signals. We also find direction-distinguishing information up to 400ms before force onset in the pre-movement signals, captured by electrodes placed over the limb-ipsilateral dorsal premotor regions. This approach can contribute to more accurate decoding of higher-level movement goals, at earlier timescales, and inform sensor placement. Our results also contribute to further understanding of the spatiotemporal features of human motor planning.
authors.lastname: Jing Wu
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Shuman
authors.forename: Bingni W
authors.initials: BW
authors.lastname: Brunton
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Steele
authors.forename: Jared D
authors.initials: JD
authors.lastname: Olson
authors.forename: Rajesh P N
authors.initials: RP
authors.lastname: Rao
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Ojemann
mesh_terms: D000069280:Electrocorticography; D004566:Electrodes; D006801:Humans; D009044:Motor Cortex; D009068:Movement; D034941:Upper Extremity