Neural correlates of learning in an electrocorticographic motor-imagery brain-computer interface

Brain Comput Interfaces (Abingdon). 2014 Jul 1;1(3-4):147-157. doi: 10.1080/2326263X.2014.954183.


Human subjects can learn to control a one-dimensional electrocorticographic (ECoG) brain-computer interface (BCI) using modulation of primary motor (M1) high-gamma activity (signal power in the 75-200 Hz range). However, the stability and dynamics of the signals over the course of new BCI skill acquisition have not been investigated. In this study, we report 3 characteristic periods in evolution of the high-gamma control signal during BCI training: initial, low task accuracy with corresponding low power modulation in the gamma spectrum, followed by a second period of improved task accuracy with increasing average power separation between activity and rest, and a final period of high task accuracy with stable (or decreasing) power separation and decreasing trial-to-trial variance. These findings may have implications in the design and implementation of BCI control algorithms.

Keywords: Brain-Computer Interface (BCI); Brain-Machine Interface (BMI); electrocorticography (ECoG); high gamma; motor imagery; motor learning.