The chapter discusses two different types of multisensory functions. This means using more then one sensory at a time, so this means using sight, hearing, touch, or taste.
One example with the moving room method. The moving room method used an observer and placed her in a small three walled room that constantly moved back and forth. Standing up on a force plate, the observer would observe the change in posture , being that the method would demonstrate your multi senses are being used to forcefully stand still.
Monkey’s do not have high levels of audiovisuals that are used in heard calls and mouth configurations. For their audiovisual calls they use brain regions which are analogous to humans. So, they are using multisensory functions to (speech) communicate.
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