What is a Hallucination?
A hallucination is a false perception occurring without any identifiable external stimulus and indicates an abnormality in perception. The false perceptions can occur in any of the five sensory modalities. Therefore, a hallucination essentially is seeing, hearing, tasting, feeling, or smelling something that is not there. The false perceptions are not accounted for by the person’s religious or cultural background, and the person experiencing hallucinations may or may not have insight into them. Therefore, some people experiencing hallucinations may be aware that the perceptions are false, whereas others may truly believe that what they are seeing, hearing, tasting, feeling, or smelling is real. In cases when the person truly believes the hallucination is real, the individual may also have a delusional interpretation of the hallucination.
Hallucinations must be distinguished from illusions, which are misconceptions of actual external stimuli. In other words, an illusion is essentially seeing, hearing, tasting, feeling, or smelling something that is there, but perceiving it or interpreting it incorrectly. An example of an illusion might be hearing one’s name called when the radio is playing. There is an external auditory stimulus, but it is misperceived. True hallucinations do not include false perceptions that occur while dreaming, while falling asleep, or while waking up.
Hallucinations are symptom of either a medical, neurological, or mental disorder. Hallucinations my present in any of the following mental disorders: psychotic disorder (including schizophrenia, schizophreniform disorder, brief psychotic disorder), bipolar disorder or depression.
Types of Hallucinations
- Auditory – The false perception of sound, music, noises, or voices. Hearing voices when there is no auditory stimulus is the most common type of auditory hallucination in mental disorders. The voice may be heard either inside or outside one’s head and is generally considered more severe when coming from outside one’s head. The voices may be male or female, recognized as the voice of someone familiar or not recognized as familiar, and may be critical or positive. In mental disorders such as schizophrenia, however, the content of what the voices say is usually unpleasant and negative. In schizophrenia, a common symptom is to hear voices conversing and/or commenting.When someone hears voices conversing, they hear two or more voices speaking to each other (usually about the person who is hallucinating). In voices commenting, the person hears a voice making comments about his or her behavior or thoughts, typically in the third person (such as, “isn’t he silly”). Sometimes the voices consist of hearing a “running commentary” on the person’s behavior as it occurs (“she is showering”). Other times, the voices may tell the person to do something (commonly referred to as “command hallucinations”)
- Gustatory – A false perception of taste. Usually, the experience is unpleasant. For instance, an individual may complain of a persistent taste of metal. This type of hallucination is more commonly seen in some medical disorders (such as epilepsy) than in mental disorders.
- Olfactory hallucination – A false perception of odor or smell. Typically, the experience is very unpleasant. For example, the person may smell decaying fish, dead bodies, or burning rubber. Sometimes, those experiencing olfactory hallucinations believe the odor emanates from them. Olfactory hallucinations are more typical of medical disorders than mental disorders.
- Visual hallucination – A false perception of sight. The content of the hallucination may be anything (such as shapes, colours, and flashes of light) but are typically people or human-like figures. For example, one may perceive a person standing before them when no one is there. Perceptions that would be normal for an individual’s religion or culture are not considered hallucinations
- Command Hallucination – A condition in which individuals hear and sometimes obey voices that command them to perform certain acts. The hallucinations may influence them to engage in behavior that is dangerous to themselves or to others.
Amanda Ogden is from Sydney Australia, and has spent the past 13 years working within the welfare industry in both administration and case management assisting people with mental health issues, mild intellectual disabilities, acquired brain injuries, drug & alcohol, homelessness gain employment. She also loves travelling, creating jewellery, music, friends and family.