A system and method for detecting subliminal facial responses of a human subject to subliminal stimuli. The method includes: receiving captured first facial response data approximately time-locked with a presentation of subliminal target stimuli to a plurality of human subjects； receiving captured second facial response data approximately time-locked with a presentation of subliminal foil stimuli to the plurality of human subjects； receiving captured unidentified facial response data to a subliminal stimulus from the target human subject； determining a target probability measure that the unidentified facial response data of the target human subject is in response to the subliminal target stimuli using a machine learning model trained with a subliminal response training set, the subliminal response training set comprising the first captured facial response data and the captured second facial response data； and outputting the target probability measure.
