Sometimes proper perception requires that two or more senses interact with one another. For example, without visual reference we can easily become confused as to the direction of motion or even the existence of motion at all. This is why pilots must trust their instruments when there are no visual references in the clouds or at night.

Give another example of a situation where two or more senses must interact in order for proper perception to occur. What would happen to our perception if one or more of the senses was missing?