Spatial perception is the ability to sense the size, shape, movement, and orientation of objects. The primary sense used to perceive spatial relationships is the sense of sight, though other senses may also play a role in determining the spatial positions of objects. Like other forms of perception, spatial perception occurs both in the sensory organs that collect data about the environment and in the brain. It is possible to notice the process of spatial perception through the use of tricks such as optical illusions, but the process in which the brain creates a three dimensional map of the area is completely subconscious.
Depth perception is one of the main components of spatial perception. The brain is able to determine how far away objects are by observing the way they pass in front of or behind one another and by judging the relative size of objects. Determining whether objects are moving and comparing the data that comes in through each of the eyes also plays a role in depth perception. When the brain analyzes all of this data it is able to approximate the distances between the observer and the observed objects as well as the distances between objects. Knowing how far away or how close objects are is an important part of spatial awareness.
Other components of spatial perception include determining the size of objects and whether or not they are in motion. The brain can determine how large or small an object is based on how it looks next to other objects and how far away it is. The motion of objects is observed through the relationship of objects to one another or through a change in perceived size.
Like other types of perception, this process happens automatically in the brain. Input from the sensory organs and information about past experiences both have a role in determining how the brain maps the environment around it. If a person has come into contact with a bowling ball, for example, that person has a rough understanding of how large that object is. This can help the brain determine how large the objects around the bowling ball may be.
Problems with spatial perception commonly lead to conditions such as claustrophobia and acrophobia. People who are claustrophobic may perceive objects as being closer to them than they actually are, a problem that can make a small space, such as an elevator, feel smaller than it actually is. Those with acrophobia may perceive that the ground as being further away than it really is, leading to a fear of high places.