you want to see something that will freak you out? at least as freaked out as you can be by something that is uber nerdy and neurosciencey? Check out this video of the McGurk effect. Watch the video, and try to identify the one syllable sound that is being repeated. Then, watch it again, but close your eyes, or look away from the screen.
Did the sound change?
The McGurk effect is an auditory illusion that demonstrates how our brains process the information we get from our senses. Generally, these pathways have some overlap which we often take for granted. For example, the same coordination of auditory and visual information being exploited in the illusion here is actually useful when you are in a bar or crouded party and you can't really hear the person you're talking to. Luckily, in real life (unlike in the video) the auditory and visual cues match up and your brain can use the visual information to help you "hear" the person next to you in that loud party. Though not exactly the same, a similar overlap occurs with olfactory (smell) and taste pathways which is why food tastes different when you have a cold or pinch your nose.
Here's another video that includes an explanation of the McGurk effect, and after that, a video showing the reactions of some viewers on a Japanese television show.