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by Dr. James Claiborn

People with BDD struggle with what they see when they look at themselves. They often report seeing aspects of their appearance that are distorted, deformed or perhaps just ugly. What any of us see when we look at anything is the product of perceptual processing. Understanding what is involved in perceptual processing is important, as it helps us understand if we should act like seeing is believing or take advice from Edgar Allen Poe, who wrote, “Believe none of what you hear and only half of what you see.”

When we see things, we are seeing the end product of two processes: sensation and perception. Sensation involves energy (light in vison) striking receptors or special cells in the back of the eye. These cells respond to the light by sending messages through the optic nerve to the brain. Perception happens when the brain processes these messages and turns them into what we experience. It is a like watching a movie with special effects in that what you experience may be very different from the what actually happened.

As a basic example, consider that the back of your eye has a place where nerves and blood vessels pass through; there are no light sensors there, creating a blind spot. If we perceived exactly the information sent from the eye, we would all see the blind spots as holes in our visual field. Instead, our brains interpret the information they receive and fill in those holes. There are a few simple ways to demonstrate this, and I leave it to interested readers to search the internet for instructions.

We also know that some perceptual effects are learned, and some are based on patterns that are preprogramed into the brain. Sometimes these patterns serve us well, but other times they lead us to perceive things in inaccurate ways. One example is the illusion of size constancy. Most people have experienced looking out of a window at a car. If you look out from the 2nd floor at a car, it looks normal-sized. However, if you look out at a car from the 20th floor of a tall building, the car now looks like a toy.  This is an example of a learned effect. Your brain “knows” that cars don’t change size when they are farther away, and compensates so that from the second floor, it looks normal sized. However, that compensation process fails when looking from the 20th floor.

Most people will have experienced watching a rotating object, such as propeller, a spoked wheel, or a fan; at first the rotation appears in the expected direction, but then the object appears to rotate backwards. This illusion is a product of how the brain processes apparent motion and is not learned.

Both the built-in and learned patterns that our brains apply to sensory information lead us to perceive things that may be very different from the stimulus. One important built-in template is one that is involved in facial perception. Infants, presented with two oval objects, will gaze at the one that has geometric shapes that approximate a face (think of a jack-o-lantern with a face of triangles and circles), and not spend time gazing at an oval that has the same geometric shapes but not arranged like a face. This suggests our brains are designed to pay attention to faces.

Optical illusions provide many examples of perceptual processing leading to inaccurate interpretation of sensory information. They can involve perception of motion, or change in size, shape, or color when there is none. If we study optical illusions, the inevitable conclusion is that all perception is illusion. Here is a link to a web page with examples of optical illusions and some explanations.

How does all of this relate to BDD? To start with, everyone looking at their own body perceives things inaccurately. However, we almost never recognize that this is the case. To make matters worse, researchers studying perception have found that people with BDD, compared to control subjects, have a deficit in recognizing emotions connected with facial expressions: they are more likely to identify facial expressions as angry. This may contribute to people with BDD concluding that other people respond critically to their appearance.

In addition, there are some behaviors that increase the occurrence of perceptual distortions, and some of these overlap with behaviors commonly found in people with BDD. The prime example is mirror gazing. Many people with BDD spend long periods of time staring into mirrors or other reflective surfaces. This behavior is best understood as a compulsive activity. The intent may be to “be sure” exactly what they look like, to examine defects or flaws, or to analyze changes, or to enable efforts to cover, disguise, or correct perceived defects. These efforts may include use of magnifying mirrors, and or getting very close to the mirror. Some people report that the part of the body they are observing in the mirror may change as they are looking at it. Staring into mirrors for prolonged periods or being very close to the mirror may increase distortion of perception, as well as produce dissociative experiences, such as feeling unreal.

While compulsive behaviors are understood to be attempts to reduce anxiety, mirror gazing may actually increase anxiety and distress and contribute to maintaining the disorder. This increase in distress is linked to the thought that, “If I see it, that must be the way it is,” i.e., seeing is believing.

People automatically respond to perceptions as if they were accurate. While most of the time this is adaptive, it is a source of problems for individuals with BDD. If they can begin with an understanding that perception is not equivalent to reality, then perhaps they can begin to distance themselves from the automatic conclusions about the meaning of what they see. They can follow Poe’s advice, and believe only half of what they see.

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