Thursday, May 10, 2012

Whose Body?

We are all familiar with the five senses of sight, hearing, smell, taste, and touch, but depending on how “sense” is defined, and what researcher you are speaking with, humans have at least four more, and as many as up to twenty-one senses.  For instance, the common definition of a sense as “any system that consists of a group of sensory cell types that respond to a specific physical phenomenon and that corresponds to a particular group of regions within the brain where the signals are received and interpreted” would lead us to conclude that pressure, pain, temperature and itch are separate senses since they involve specific receptor cells, while others continue to think of these as sub-categories of touch.

Those of us who practice yoga are all familiar with the following two senses:

Proprioception:  This sense gives you the ability to tell where your body parts are, relative to other body parts.  The “close your eyes and touch your nose” test given to suspected drunk-drivers is testing this sense.  This sense is used all the time in little ways, such as when you scratch an itch on your foot, but never once look at your foot to see where your hand is relative to your foot.

Equilibrioception:   This is the sense that allows you to keep your balance and sense body movement in terms of acceleration and directional changes as well as for perceiving gravity.  The sensory system for this is found in your inner ears and is called the vestibular labyrinthine system.  Without it you wouldn’t be able to tell up from down and moving from one location to another without aid would be nearly impossible.

Another sense, interoception is the awareness of the internal state of one’s body. Interoception informs us of emotions, pain, thirst, hunger, and body temperature. And, just as some of us have more developed or less developed sense of hearing or smell, people vary on how well they receive cues as to these bodily states.

Many have argued that (photoshopped, airbrushed) images of unusually thin people have contributed to the overwhelming instances of negative body image among women – and now increasingly so among men. In June 2011, the American Medical Association (never accused of being a radically progressive organization) released a statement that urges advertisers to stop the use of digitally altered photos after researchers found links among exposure to mass media, negative body image, and disordered eating.

Almost half of adolescent girls report being dissatisfied with their appearance, and one out of 20 Americans suffers from a clinical body image disturbance where people are plagued with thoughts about minor or imaginary “flaws” in their appearance.

That said and understood, the question becomes why is it that with all of us exposed to images of so-called “perfect bodies,” we don’t all suffer serious body image issues? In fact, this is the question that critics have lobbed against those who argue against the negative impact of the media. It should come as no real surprise that myriad factors – including environmental and biological – must arise together to create pathology. One of the potentially biggest biological factors is a deficit in interoception. This finding points to possible ways to treat these ailments and in particular the potential of hatha-yoga – when practiced as a mindfulness practice – to foster a more speedy recovery.

Interoception – the awareness of our bodily state – arises when receptors throughout the body send signals to the insula, a small area of neural tissue nestled in a deep fold of the brain’s external layer near the ears. Combined with external information, the insula would be that part of the brain that connects the searing sensation experienced when touching a hot stove with the red welt on our hand. It is this integration that forms our body image.

The greater the influence from interoception over external, visual cues, the better a person’s body image. For instance, a yogini practicing with strong interoception might be focusing on the sound of her breath and the rising and falling of her abdomen with her breath that would cue her to adjust the intensity of her efforts. By paying attention to her body’s functioning and experience, she feels good about it no matter its proportions. A yogini with poorer interoception, however, might be thinking about what others in the class think of her postural performance or whether her butt looks too big in her new stretch yoga pants. Because of the weakness of internal cues to anchor her sense of self, if she is practicing in a mirrored room, she may focus on small visual details reflected in the mirror, potentially diminishing her body image.

Distorted body image, clinically known as “body dysmorphia,” ranges from the so-common-jokes-are-made-of-it worry about whether these jeans make one’s ass look fat to the delusional misperception of body size seen in anorexia nervosa. Interestingly, people can have the reverse misperception. A 2010 study at the University of Texas Southwestern Medical Center found that almost one in ten obese adults thought their weight was normal.

When tested, people with lower measures of interoception have increased levels of body dissatisfaction and more instances of disordered eating. Women suffering anorexia, scoring very low levels of interoception, also suffered more from depression and anxiety and significantly higher levels of body dissatisfaction. Studies have found that the insula of women suffering from anorexia tends to be unresponsive, measured by diminished blood flow shown in MRI scans.

Another fascinating finding is that when healthy women are shown photographs of themselves, there is a burst of activity in the insula, suggesting that the photo enhances a person’s experience of what it is like to be inside her own body, while no such activity results when a women with anorexia is shown photos of themselves. This suggests that women with anorexia lack the ability to link external cues about their appearance to internal knowledge of their body, which is likely to be quite low already. This helps explain how an emaciated women with anorexia can look at her reflection in a mirror and “see” herself as being fat.

What does this have to do with media? It turns out that deficiencies in interoception may make your body image more vulnerable to other, external visual influences! In one study, it was found that women with anorexia, having lower body awareness, are more easily fooled into the rubber hand illusion. The researcher on this study, Manos Tsakiris of Royal Holloway, University of London, thinks this implies that media images will have an exaggerated effect on those with little internal awareness.  Additionally, those with poor awareness of their internal state also seem to be easily swayed by the opinions of others. Cultivating greater interoceptive awareness could not only improve body image, it seems, but it could strengthen a fragile sense of self and self-worth.

And, as it might have been expected, numerous studies have found that mindfulness-based cognitive-behavior therapy has attenuated symptoms of disordered eating and body dysmorphic disorder, leading to an enhanced quality of life. Other studies have investigated the practice of yogasana – various forms of hatha-yoga, including vinyasa-flow – and found that as long as practitioners are reminded to focus attention on their breath and the various bodily sensations produced by the practice (basically, Mindfulness Yoga), the practice of yogasana does indeed get people more in tune with their body and their experience of the body. I would suspect that those forms of yogasana practice where students are exhorted to “push” or “ignore the pain,” might actually feed into the pathology by diminishing self-awareness of bodily sensation.

One study, working with adolescent girls suffering disordered eating, found that they were so out of touch with their body that they had great difficulty balancing on one foot. Through mindfulness practice integrated into their asana practice, they were able to find their balance easily in only eight weeks, while showing great improvement in all areas of eating disorder psychopathology.

It is helpful to remember that in the buddhist tradition of practice, the first two of the four foundations of mindfulness are the body and feelings. When practicing with the body, the main focus is the breath, and once focus is developed, mindful attention is expanded to include the whole body, it’s posture and movements, while paying attention to how the breath affects the body and how the body affects the breath. The second foundation, feelings, refers not to the emotions, but rather to the actual sensations experienced in, on and throughout the body – as well as the tone whether pleasant, unpleasant or neutral.

As a new yoga teacher, back in the mid-90s, one of the first awakenings I had was regarding just how out of touch so many of us are with our body! With the advent of the internet, i-phones, i-pads and other technologies, I believe it’s only gotten worse! It now seems to me that many folk live from their eyebrows up! One of the most healing things we can do as yoga teachers and practitioners is to simply become more familiar with the felt experience of the body, and to help foster a safe, open and free space for our students to come home to their body, just as it is, here…now.

Further Reading:
This blog piece is a distillation of the article:
Inside the Wrong Body. C. Arnold in Scientific American Mind, Vol. 23, Number 2, May/June 2012

Just a Heartbeat Away from One’s Body: Interoceptive Sensitivity Predicts Malleability of Body-Representations. M. Tsakiris, A. Tajadura-Jimenez and M. Constantini in Proceedings of the Royal Society B, Vol. 278, pages 2470 – 2476; August 22, 2011

Functional Neuroimaging in Early-Onset Anorexia Nervosa. B. Lask et al. in International Journal of Eating Disorders, Vol. 37, S49 – S51; 2005. Discussion on pages S87 – S89.