July 20, 2010
Scientists at University College London asked people to put their left hands palm down under a board and judge the location of the covered hand’s knuckles and fingertips with a pointer. The results pointed out that people tend to think that their hands are wider and their fingers are shorter than they truly are. Lead researcher Dr Matthew Longo recognized how the findings may well be relevant to psychiatric conditions involving body image such as anorexia nervosa.
Susan Ringwood, chief executive of the eating disorders charity Beat, said:
“We know that one of the features of anorexia nervosa can be distorted body image. People affected can truly believe that they are grossly fat, even when they are dangerously underweight. They are able to judge other people’s bodies quite accurately and would describe someone else the same size as themselves correctly, but still not be able to do that about their own weight and shape.”
“This brain study may give some insight into how this could be possible, and could be very motivating for people with eating disorders to know that there was a biological explanation for their experiences, rather than feeling it was their fault.”
Obviously, the brain tends to make body image projections that are wider and shorter than the body (hand) really is. And women are typically known for experiencing more problems in visuo-spatial tasks!
But there’s more known about how hands relate to anorexia…
FINGER LENGTH & EATING DISORDERS!
But there is another connection between anorexia nervosa and the hand: it’s in the length of the fingers!
High 2d:4d digit ratio (the typically female-like finger length variant) has been associated with low levels of prental testosterone exposure AND high levels of eating disordered behaviors. Michael D. Anestis reports:
“Drive for thinness was lower in men with a lower 2D:4D ratio and drive for muscularity was higher in men with a lower 2D:4D ratio. …A lower 2D:4D ratio also predicted lower levels of eating disordered behaviors in men. …So, what do these findings tell us? First of all, it appears that, for men as with women, a greater level of prenatal testosterone is associated with less of a drive to be thin and lower levels of eating disordered behaviors. Additionally, a greater level of prenatal testosterone exposure appears to predict a greater drive to develop a muscular physique.”
So, next to the brain-created body image distortions – prenatal testosterone is also involved in anorexia nervosa related eating disorders.
Please feel free to share your thoughts…
SUGGESTION FOR FURTHER READING:
• Is Madonna suffering on body dysmorphobia?
• Fragile hand of a young girl in Uganda!
• Superbabe Megan Fox learned how to live with her unusual thumbs
• What your physique reveals about your health!
June 12, 2009
The role of the skin on our fingertips, palm and soles of the feet is to grip other objects, and they all have characteristic “friction” ridges. Nevertheless, very little research has been carried out about how well fingers perform, how friction is achieved and why we have soft fingerpads with fingerprints at all. Recent research carried out in the laboratory of the University of Manchester suggests that finger skin has frictional properties rather like rubber.
|Why do we have fingerprints?
The most likely possible answers are:
1) Fingerprints may increase friction on rough materials;
New British research indicates that the first option can be deleted from the list. Researcher Dr. Roland Ennos explains his findings below:
“I have been thinking about this for years and, having played around with it for a bit, realised that skin is rubbery so the ridges in fingerprints might actually reduce grip.
Our experiments – using a plastic cup, weights and strips of Perspex (acrylic glass) to develop a simple machine in the lab – proved me right.
The experiment was so simple, this discovery could have been made 100 years ago; but scientists make assumptions and tend to look at complicated things instead.
We are now testing that theory and two others, that fingerprints improve grip on rough surfaces and that they increase sensitivity.
There are potential spin-offs for this work. For example some people who suffer nerve damage that prevents sweating have slippery fingers and cannot grip: we could develop something to treat that.”
LEARN MORE ABOUT FINGERPRINTS:
In may 2009 Dr Roland Ennos and his team at The University of Manchester presented fingerprints findings with a surprizing outcome. Fingerprints do not help primates grip, as previously thought. Instead, a fingerprint actually reduces the friction needed to hold onto flat surfaces.
Dr Ennos disproved the long-held assumption that fingerprints help primates to grip with a simple machine, three strips of perspex and the right hand of Masters student Peter Warman. They tested the student’s grip on every finger + thumb at three different widths of perspex as the machine pulled the perspex strips down via a weight in a plastic cup. The researchers also tested grip at three different angles by bending both the fingers + the thumb. This wide range of testing conditions allowed them to separate pressing force from the contact area and overcome any confounding variables.
The results indicate that fingertips act more like rubbers than hard solids; their friction coeficient fell at higher normal forces and friction was higher when fingers were held flatter against wider sheets and hence when contact area was greater.
WHY DO WE HAVE FINGERPRINTS?
“The experiment was so simple, this discovery could have been made 100 years ago; but scientists make assumptions and tend to look at complicated things instead.
My preferred theory is that they allow the skin to deform and thus stop blistering. That is why we get blisters on the smooth parts of our hands and feet and not the ridged areas: our fingerpads, palms and soles.”
SUGGESTIONS FOR LEARNING MORE ABOUT FINGERPRINTS:
Many people often fee tired and experience the feeling like having ‘pins and needles in your fingertips’. It might be a sign that you’re having a vitamin B12 deficiency – especially if you’re a vegan. However, there are other causes for having this rather painful feeling in the hands and fingers.
The medical name for feeling pins and needles in your fingers is ‘paraesthesia‘. Paraesthesia is a sign that sensory nerves in the area of the tingly sensation are being irritated – sometimes this condition is combined with small colour variations in the hand (pink/yellow spots). The condition may be the result of a disease or damage to the nerves themselves, damage to the blood supply, or disease of the surrounding tissues (arthritis the nerves themselves get affected).
Pins and needles are a more complaint as people get older – poor blood supply is then likely the cause because of atherosclerosis or hardening of the arteries. Millions of people in the developed world suffer on the feeling of having pins and needles in the hands & fingers – and often the conditions is associated by the people with RSI.
So, there are a variety of possible causes:
• Carpal Tunnel syndrome;
Karen Evennett (free lance journalist) says:
“There’s far more to reading hands than fortune-tellers’ mumbo jumbo – it can be a life-saving skill if you know what to look for. Pins and needles in your fingers is a sign that you’re lacking in vitamin B12, which is essential for energy and the nervous system. A deficiency is more likely if you’re vegan, as the main sources are meat, fish, eggs and dairy.”