Hallucinations and the Human Consciousness
The idea of consciousness has been contemplated throughout the course of neurobiology and behavior. When does it begin or end? And what, precisely, is consciousness? Though researchers may only approximate the answers to these questions, a few things may be inferred. Since the subconscious mind is the sleeping mind, the conscious mind can be thought of as the awakened mind, the mind which shows itself to others most often. (1) This is not to say that the conscious mind is reality, because (as will later be explained) reality is quite subjective. (1) It is just that the conscious mind is the one most people associate with reality. For example, people who experience an event while dreaming will refer to it as a dream, because it occurred in their subconscious. Whereas, if the event had occurred while they were awake-in their conscious mind-frame, then it would be considered as an actual experience.
The designation between subconscious and conscious or reality and dreamlike states seem to be cut and dry. However altered mind-sets confuse the line and cause hallucinations. When we dream, our thinking is mostly pictorial and depends on memory. (1) We may hear words, but we understand most of the dream through pictures and people from the past or present. As we awaken, our mind switches from pictorial thinking to word-based thinking. (1) Hallucinations occur when the mind does not completely switch, or switches back, to the conscious state. (1,2)
The first thing to note about hallucinations is that they have long been associated with mental illness because many people become confused as to what they are seeing or experiencing. (2) Though hallucinations do occur in mentally ill people (most commonly in people with schizophrenia or bipolar disorder), they can occur in "normal" people as well. (1,2) Since there are many causes of hallucinations--lack of sleep, drugs, certain types of epilepsy, and prolonged meditation-not all causes are related to psychological disorders. (1) The second important issue concerning hallucinations is that people who experience hallucinations experience a lapse in perception. (1,2,3) People who hallucinate often know what they are experiencing is caused by external factors. Therefore their perception of events is being altered, but not to the extent where they believe in a different reality. (An alteration of reality is referred to as a delusion, which is more serious than a hallucination.) (2)
Our perception is not absolutely real. Our brain filters the environment through sensory areas. The brain's cognitive ability allows us to organize the stimulus from the external world and perceive it as the "real" world. Basically, our perception is only an approximation of reality. Since we are already constantly thinking through representations and symbols, it is not that difficult for our perception to be skewed...