1. A system, comprising: a data collector to obtain first electroencephalography data from a first frequency band, second electroencephalography data from a second frequency band different than the first frequency band and occurring at a first period in time, and functional magnetic resonance imaging data from a subject exposed to an advertisement or entertainment; a filter to remove interference from each of the first electroencephalography data, the second electroencephalography data, and the functional magnetic resonance imaging data; an intra-modality response synthesizer comprising a processor configured to: detect a first pattern of oscillation in the first frequency band; detect a second pattern of oscillation in the second frequency band; generate, using a processor configured to, a coupling index based on a phase synchrony between the first frequency band and the second frequency band, wherein the phase synchrony is determined by detecting a repeating sequence of relative phase angles between the first pattern of oscillation in the first frequency band and the second pattern of oscillation in the second frequency band; and a cross-modality response synthesizer to analyze the coupling index and the functional magnetic resonance imaging data to evaluate effectiveness of the advertisement or entertainment at the first period in time.