Media and the brain
Media imprints its information onto the brain directly, complete with its hidden levels of meaning representing values, ethics, esthetics, etc.
The audio/visual senses are the two most impactful senses on the brain. Correspondingly, audio/video media is the most developed area of delivery.
Brains need to be trained to receive media. A normal brain creates a mental model of reality based on events that are witnessed by the senses. This mental model is built up by the sense data, again audio/visual in large part, and given a high degree of belief by virtue of the first-hand experience.
In the case of media, an alternate world is presented. This world is still self-consistent, and competes with the "reality" model in the brain. In fact, models are merged, and the media models can both fill in the gaps where the reality model has no explicit links, and also replace the reality model in some cases.
An untrained brain will assign high degrees of belief to the media models, because of their audio/video fidelity, and because of the dramatic emotional effect inherent in any media production. The result is an individual who is more easily controlled by the media.