A better understanding of human perception unlocks the key to how the mind works, an advantage when working with people with mental disorders.
The below diagram is an illustration as to how we all perceive things in our own way, as suggested by the theories of Jung and Freud.
What do you see? Some of you may see 2 green faces, other may see a white chalice. This all depends on your initial perception of the diagram. You may find that when you look again, you may see the alternate picture within the diagram.
The retina is responsible for interpreting visual stimuli such as this, where it picks up photons of light via the 130 000 000 rods and cones situated on it. In pre-modern times it was considered that visual perception simply encompassed what was seen by the eye on the outside. This external stimuli would in turn produce a perception in the brain caused by the stimulus.
However this is not the case. Modern medicine now knows that information from the eye is simply a physiological process that does not actually process the signals it receives. This job is left to the brain.
The senses simply act as a messenger to a particular stimulus that is seen, the brain is the place where external stimuli is actually perceived.
The environment we live in is 3 dimensional, thus needs a 3 dimensional approach to understand it. Therefore height, width and depth must be measured by the eyes
This is possible by the way the eyes are situated on the head. Positioned either side of the nose, the right eye picks up vision on the left hemisphere and the left eye picks up vision in the right hemisphere.
The images picked up by the eyes are projected upside down on each of the eyes retina. This in turn will be perceived the right way up by the brain, which will interpret the three dimensional values of the external environment at a very fast and effective rate
It is possible for the physiological state of the brain to deviate from the norm and trigger of a mental disorder. Illusions are a symptom of such mental disorders.
However it is also possible to trick the senses of a perfectly functional healthy brain. Illusions, such as the mirages that appear in the desert are caused by trickery of the sense, leading us to believe there is something out there when this is not the case.
More information on illusions and mind trickery are looked upon in the next page