Distortions of Body Image

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When we speak of our physical selves, we are often referring to the image we have of our body, as it is represented in the mind. Many faculties are involved in creating this mental representation; some are sensations which we receive as input to the nervous system. These immediate experiences allows for the perception that there is a unity of the body, but this perception is grounded in assumptions and preexisting information about the body. Knowledge of the body is organized to fit a certain schema that permits one to view themselves as a complete embodied person. The mental image of our body schema is the body image. It comes to us through the senses, but is not a mere perception; there are mental pictures and representations involved in it, but it is not a mere representation.

            A dynamic process is used to consciously organize and construct a subjective understanding of one’s phenomenal experience of the body image. A distortion occurs when a person’s image or representation of their body is substantially different from reality. Body image distortions commonly occur with the development of eating disorders. The onset of image distortion and eating disorders, most notably anorexia nervosa, is multifaceted and is influenced by sociocultural, psychological, hereditary, and brain chemistry factors indicative their environment (6).

            Anorexia nervosa is an eating disorder where one exhibits a refusal to maintain body mass over minimal weight normal for their age and height. Someone diagnosed with anorexia nervosa displays a fear of gaining weight and being fat, as well as exhibiting a disturbance in the way in which one’s body weight, size, or shape is experienced. Characteristic behaviors include: diminution of food intake, some binge episodes followed by purging, rigidity, ritualism, perfectionism and meticulousness (7). Anorexia nervosa is often accompanied with depression and anxiety and individuals deny or minimize severity of their illness. Anorexia may also have shares characteristics with obsessive and compulsive behaviors in that many of the behaviors individuals display are accompanied with checking behaviors. These obsessions tend to cause marked distress and significantly interferes an individual’s normal routine (7).

            Anorexia does not simply result from a desire to be thin; a person with the disorder has a disturbance in their body image so they believe with are overweight, when they may, in fact, be extremely undernourished. While Anorexia is due, in part, to malfunctions of some neurobiological systems, it is important to note that cultural values are also important in understanding how individuals perceive themselves and others. A given culture clearly places a strain on individuals to conform to its standards, ascetically or otherwise. After all, if the culture values a certain definition of attractiveness of its members, then the individual will value that attractiveness in themselves and others, and attempt to meet that definition. Cultures were food is plentiful and has a dominating presence, mostly developed countries, show a tendency toward eating disorders. Eating disorders also appear to run in families; which suggests that genetic factors may predispose some people to eating disorders.                     

            The influencing factors mentioned, along with others, work in conjunction in the development of the characteristic distorted body image of anorexia nervosa. In order to fully understand this disorder we must develop an understanding of body image, its origins and where else it appears to be affected. Body-image distortions occur when a person's mental representation of their body is significantly different from reality; it is a disturbance in an individual’s internal picture of exterior form. For the majority of people, their body image roughly matches their actually figure. However, for those with eating disorders this mental picture becomes warped.

            This warped image is not exclusive to anorexia, as it is seen in similar forms in other disorders. An example of such is asomatagnosia; a body image impairment which often causes the individual to become unaware of particular body parts as one’s own or ignorant to the fact that they are paralyzed or numb (3).  Here there appears to be an obvious alteration in the representation of the body, which is likely to be independent of sensory pathways because it contradicts the information that one’s limbs are presumably sending. A person asomatagnosia has a mental representation of their body which causes them develop expectations. When the represented image is contradicted by sensory input the most logical explanation the mind can come to is that the limb does not belong to the body. 

Another example of altered body image is body dysmorphic disorder, which can be described as having a preoccupation with one’s appearance, experiencing interior bodily sensations as altered in someway or exhibiting preoccupations with some imagined defect in appearance (3). Individuals with body dysmorphic disorder, and most body image disorders, experience persistent ideas, impulses or images that are “experienced as intrusive and senseless”(3). Individuals typically recognize these experiences as a product of their mind; however this does not make the symptoms any less real since everything you experience is essentially a product of the mind.

            Similar to other body image disorders, individuals with hypochondriasis experience a fixation of bodily sensations. The disorder is distinguished by a fear of or belief that one has a serious disease which is based on the faulty interpretation of physical signs as evidence (7).

            These disorders, along with many others, all share the impairment of body image, similar to that seen in individuals diagnosed with anorexia nervosa. The variations in the way the body image is altered illustrates that this mental representation is multifaceted, and a change in any one of these areas can distort the way in which the body is perceived. One possible cause of distortions in body image may occur when parts of the somatosensory cortex are abnormally amplified, causing unexplained sensations which the mind must account for (3). The mind creates a parsimonious explanation to account for the new information and how relates it to prior knowledge. Therefore, in order to accommodate the large array of received information, body image most likely does not depend on a specific localized brain module, and is affected by larger regions. This accounts for the large variation of different types of body image disorders because there is a greater region which, when affected, results in a dysfunction of body image.

New image technology is now finding that dopamine pathways are overactive in people with anorexia nervosa. In an extremely simplified explanation, there are mechanisms in the brain where dopamine facilitates assessment information which is then compared to similar preexisting information (8). The brain then processes this information and determines whether it is “rewarding” or “harmful” in order to allow an individual to make an appropriate decision for a given situation situation. Patients with anorexia process “rewarding” stimuli differently than the average individual. The new imaging technique suggests that “the dopamine system may be over sensitive to stimuli and/or stimuli is aversive” (8). For those with anorexia, food is one of these stimuli, and this may explain why eating may not be rewarding for them. Additionally, other stimuli may be unrewarding or overwhelming, which may explain why there is often self denial and restraint, as a way of controlling and reducing stimuli.

Other research has shown higher than average levels of cortisol, a brain hormone released in response to stress, in people with anorexia. Interestingly, these levels are also prevalent in certain forms of depression, which usually accompanies anorexia. The excess levels of cortisol, in both anorexia and depression occurs from dysfunction in the hypothalamus, whose main function is homeostasis, or maintaining the body's status quo (6).

            A tremendous amount of research has provided biochemical explanations for the behaviors observed in patients with anorexia nervosa, but these do not provide incite into the origins of body image dysfunction. Body image embraces all that we come to know as our own body; it is an idea and perception and is the limit of what can be called “my body” in phenomenal experience. A body image is an internal representation of one’s outward appearance, and involves a reflexive intentionality because it consists of a complex set of intentional states, such as perceptions, mental representations beliefs and attitudes, in which the intentional object of these states is one’s own body.

The idea of the body, or body image, is not specifically represented by a particular part of the brain. The nervous system has a readily available repository of information about itself that it can reference when needed. In fact, because the brain is topographically organized we can use a “somosentory map” to explain how we experience and identify various parts of the body (6). The mind uses this information along with a cumulative set of images, fantasies and meanings about the body and its parts and functions to create a body image and self representation.

            Contrary to what the name implies, body image is not static, but a dynamically and developmentally evolving process represented in an effort to organize and construct a subjective understanding of one’s phenomenal experience. Body image is dynamic in that it entails a mental construct created by the sensory impressions, perceptions and ideas about the structure of ones’ body. There are actually several aspects of the body, such as body size, for which there are not specifically designated receptors. It is the brains job to consider several different streams of information and create a coherent picture (1).          

Body image, also referred to as corporeal awareness, has been found to rely upon the posterior parietal lobe and insular cortex. In a position emission topographic study it was shown that “a posterior parietal system is activated during mental transpositions of the body in space” (1). Also involved in body awareness is the insular cortex, particularly in relation to the emotional aspects. This deduction is based on the fact that “lesions can cause somatic hallucinations and electrical stimulation near the insular induces illusions of change in body position and feeling of being outside ones body” (1).

It has been conjectured that humans may be genetically predisposed to form a mental representation of a prototypical human body. We may be equipped with a mechanism for the imitation of simple actions and while we mature these mechanisms undergo a gradual refinement as a consequence of the systematic interaction between tactile, proprioceptive and vestibular inputs; as well as interactions between inputs from the visual perception of the structure and movements of ones own and others bodies (1).

Experimental findings have shown that an innate communication between the visual and motor systems can be observed in infants only hours after birth, as seen in the ability of an infant to imitate the actions of another without any insight into the structure of its own body. This may confirm a genetically determined neural framework for the experience of the body and also indicates that the experience is open to modification over the human lifetime.  The differentiation between the experience of the body and body image comes about as the individual develops and adds to their repository of experience (3)(1).

            The individual then undergoes an ongoing process of proprioception and information collection that lend itself to the construction of the body image. While these do not exclusively create the body image, they work with other factors and expectations in order to give shape to this constantly changing representation. This constructive activity integrates and differentiates the transitory experience of one’s own body and provides phenomenal experience of constancy and stability (1).  

            Once this complex system of creating corporeal awareness is in place, it is continuously affected by both internal and external expectations, and because this process is so dynamic there are many possible origins for error that could result in distorted body image (3). Anorexia nervosa is only one of many examples where individuals experience a distortion of their body image. With anorexia nervosa an individual has a somewhat warped body image, but dysfunction can go so far as to cause one to lack a clear perception that a body part is absent. For example, an amputee or someone who feels nothing below the level of the spinal transaction feels that they are embodied and whole as a person. Viewing themselves as an embodied person shows that they have a mental representation of their body separate from, but affected by, the input received from the body (6).

The body image is obviously not a simple percept of the body, but involves mnemonic and imaginative components as clearly demonstrated by the compelling amputee’s experience of the continued existence of the amputated body part. Visual, auditory and olfactory phantom sensations have been reported after deafferentation of the corresponding sense organs, but the most obvious phantoms are undoubtedly somaesthetic in nature; from pain to feeling of movement, from touch to the feeling of hot or cold being represented in the phantom experience (6).

Though this instance does not initially appear to relate the shared distorted body schema allows us to link, not only the disorders, but their causes and treatments. Bridging this information gives us a more holistic view of what is actually occurring in the mind to allow us the form these mental representations of our physical form. From here we can begin to develop a deeper understanding of illnesses like anorexia nervosa and possible even develop treatments aimed at the heart of the problem, the distortion of body image, instead of attempting to cure the symptoms.

What the body image shows us is that the mental representations, the story which the mind creates about the body, may not be consistent with the sum total of sensory experience. This profound disagreement could be the root of the problems seen in disorders involving body image. The mind attempts to reshape this notion in order to make the input and image more compatible. This process is not exclusive to the profound disagreement, seen in body image disorders; all individuals are continually comparing summary and observations of what they are and what they would like to be and modifying themselves accordingly. It is by observing dysfunctions in this process and in the body image that gives us incite about the processes of the mind.

                  1) Berlucchi, Giovanni and Salvatore Aglioti. The Body in the Brain: Neural Bases of Corporeal Awareness. Science Direct. <http://sfx.exlibrisgroup.com:9003/brynm?sid=google&auinit=G&aulast=Berlucchi&atitle=The+body+in+the+brain:+neural+bases+of+corporeal+awareness&id=pmid:9416668>

2) Brain theory of eating disorders. BBC.com. <http://news.bbc.co.uk/2/hi/health/4144755.stm>

 

3) Cash, Thomas F and Thomas Pruzinsky. Body Image. Guilford Press. <http://books.google.com/books?hl=en&lr=&id=qZN7w2kXxtoC&oi=fnd&pg=PR7&dq=neurobiology+%2B+body+image+disorders&ots=a_wwKp7oxY&sig=R4Z4DWmeD9v0qHWADplF5RPqvS0#PPP1,M1>

 4) Christie, Catherine. Body Image. < http://www.faqs.org/nutrition/Ar-Bu/Body-Image.html> 

5) Eggers, Christian and Verena Liebers. Through a Glass, Darkly. Scientific America.com. < http://www.sciam.com/article.cfm?chanID=sa017&articleID=C71BE929-E7F2-99DF-3F2D3BA1CA0FF35F&ref=rss>

 

6) Hoffman, Lee. Eating Disorders. National Institute of Mental Health. <http://www.mentalhealth.com/book/p45-eat1.html#Head_5>

Mohr, Christine and Olaf. Implications of Neurocognitive Mechanisms of Corporeal Awareness. Elsevier.com. <http://lnco.epfl.ch/webdav/site/lnco/users/149176/public/9.Blanke%20O,%20Mohr%20C.%20(2005)%20Autoscopic%20phenomena%20of%20neurological%20origin.%20Implications%20for%20corporal%20awareness%20and%20self%20consciousness.%20Brain%20Research%20Reviews%2050:184-199.pdf>

 7) Hollander, Eric. Obsessive-Compulsive Relate Disorders. American Psychiatric Publishing. < http://books.google.com/books?hl=en&lr=&id=R-GRXVsFFEgC&oi=fnd&pg=PR7&dq=neurobiology+%2B+body+image+disorders&ots=nJ0Q5sgMxr&sig=4pcARQzoXfrcsu7UqXD0pRlJ4ok#PPA18,M1> 

8) Kaye, Walter H. Understanding the Neurobiology of Eating Disorders. UCSD - DEPARTMENT OF PSYCHIATRY. <http://eatingdisorders.ucsd.edu/neurobiologypage.html>

 9) Paqueron, X. , M. Leguen, D. Rosenthal, P. Coriat, J. C. Willer and N. Danziger.  The Phenomenology of Body Image Distortions Induced by Regional Anaesthesia. Oxford Journals.  < http://brain.oxfordjournals.org/cgi/content/full/126/3/702>   

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