How Ventriloquism Tricks the Brain

Our five main senses — sight, hearing, touch, smell and taste — take cues from our environment by sending a constant stream of signals to the brain. When the brain comes across a “glitch” in the information it’s getting from its surroundings, it can lead to some peculiar illusions. Ventriloquism is one example. The classic example of this illusion is a performer on a stage with a puppet sitting on their knee. This is where the ventriloquist illusion tricks the brain. The sensory information from vision is not reliable. The puppet’s mouth is moving, but there’s no sound coming out. The sense of hearing is overruled by vision and, as a result, it genuinely seems to us that the puppeteer’s voice is coming straight out of the puppet’s mouth. It’s beautiful but very complex. Far from a seemingly trivial party trick, the ventriloquism illusion actually says a lot about the fundamental ways our brains make sense of the sensory information we receive from the world around us and how one sense can override another.