I had my annual viewing of Susan Boyle on Britain’s got talent this morning. Then I came across this amazing demonstration of what photoshop can do. Watch that, or watch for a little while and go to the end – it is a bit tedious. We and others have shown that our cognitive representation of our body affects our body – we have shown that getting the illusion that you own a rubber hand makes your own hand a bit colder and that seeing a swollen hand makes your own hand a bit more swollen. We wonder if this top-down effect extends to metabolic regulation – is it possible that if you think you look a particular way, your body changes the way it works to match that? I concede it sounds pretty far-fetched, but it is not an outrageous possibility.
When experienced bartenders estimate a shot of alcohol, they overestimate by about 20% when they use a short fat glass instead of a long skinny one and a meal served on a big plate leaves people feeling less satiated than the same meal served on a small plate. We perceive mountains to be steeper if we have a heavy load on our back and we perceive a glass of water to be closer if we are thirsty than if we are not. So, clearly our cognitive representations of things seem to modulate all sorts of things. If we actually perceive ourselves to be very fat, do we speed up metabolic rate or switch the balance of energy sources in our body? Could the fake body norms that are now in place by virtue of photoshop actually be messing with our own bodies as well as our minds? If so, then the complexity of the mind-body link just got a whole lot more complex – our body modulated by the mind of a magazine editor in LA?
Wansink, B. (2005). Shape of glass and amount of alcohol poured: comparative study of effect of practice and concentration BMJ, 331 (7531), 1512-1514 DOI: 10.1136/bmj.331.7531.1512
Brian Wansink and Koert van Ittersum (2006). The Visual Illusions of Food: Why Plates, Bowls, and Spoons Can Bias Consumption Volum The FASEB Journal, 20:A618
Moseley GL, Olthof N, Venema A, Don S, Wijers M, Gallace A, & Spence C (2008). Psychologically induced cooling of a specific body part caused by the illusory ownership of an artificial counterpart. Proceedings of the National Academy of Sciences of the United States of America, 105 (35), 13169-73 PMID: 18725630
Moseley GL, Parsons TJ, & Spence C (2008). Visual distortion of a limb modulates the pain and swelling evoked by movement. Current biology : CB, 18 (22) PMID: 19036329