Devices, systems and methods for a brain-computer interface (BCI) system for correlating brain activity of a user to a predetermined physiological response, a predetermined classification of a user intention or a predetermined mental state to control, for actuating a control action. The BCI system including an input interface to receive brain signals indicative of an activity of a brain of the user. An encoder to encode the received brain signals to produce a sparse connectivity map of correlations among active regions of the brain. Wherein the sparse connectivity map specifies more zero correlations than non-zero correlations between various active regions of the brain. A classifier to classify the sparse connectivity map as an intended predetermined physiological response intended by the user. A controller to communicate a control signal for actuating the control action according to the intended predetermined physiological response to a device.