Copyright

What is a Hallucination? - Definition, Causes & Types Video

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Source Amnesia: Definition, Causes & Impact

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:01 Understanding Perception
  • 0:40 What Is a Hallucination?
  • 2:20 Causes of Hallucinations
  • 3:14 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Timeline
Autoplay
Autoplay
Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Sarah Lavoie

Sarah has taught Psychology at the college level and has a master's degree in Counseling Psychology.

Hallucinations consist of far more than just seeing things that are not there. In this lesson, we will define and explore different types of hallucinations as well as their many causes. Then take a quiz to test your knowledge.

Understanding Perception

At quick glance, what is the image in this picture?

When looking at this image, you're using your sense of sight to perceive what is there. So, is this an image of a vase, or is it two people facing each other? Which did you see first?

We become aware of and identify what is going on around us through our perceptions. Unfortunately, the five senses do not give us the whole picture. Tasting, hearing, smelling, feeling, and seeing are only the beginning of the sensory process. Although two people may be confronted with the same experience or stimulus, it's common for them to process the information differently.

What Is a Hallucination?

A hallucination is different than an illusion like the one above. Illusions are common misinterpretations of a stimulation to the senses. Hallucinations are misinterpretations in the absence of a sensory stimulus.

Most people have experienced seeing, hearing, and feeling things in the state between wakefulness and sleep. The hallucinations that occur upon awakening are called hypnagogic hallucinations. Those seen while falling asleep are called hypnopompic hallucinations. Neither are preceded by stimulation to one of the senses, but both are completely normal.

Although we may immediately associate seeing things with hallucinations, visual hallucinations are not the most common type of hallucination. Auditory hallucinations, such as hearing voices, are the most common. But hallucinations can occur with any of the senses, or even a combination of senses. Here are some other types of hallucinations:

  • Olfactory hallucinations: smelling things that aren't there
    Jane looks around because she smells smoke. She searches for the source of the smell, as it gets stronger and stronger. But there is no fire.
  • Haptic hallucinations: feeling things that aren't there
    John sits at his mother's dining room table. He's fascinated by how the tablecloth feels like velvet, and he continues to rub his hand over it to feel the fibers. The tablecloth is cool, smooth plastic.
  • Gustatory hallucinations: tasting things that aren't there
    Jane is driving home from work. To her surprise, as she gets closer to home, she begins to taste pickles from her grandmother's secret recipe.

Causes of Hallucinations

Psychologists are certain that physiology of the brain plays a role in hallucinations. Patients who previously report hallucinations often have lesions that are located in areas of the brain responsible for the type of hallucination they experienced. Various injuries, illnesses, genetic disorders, and certain drugs can induce hallucinations in people.

Here's a list of some other causes of hallucinations:

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account
Support