Have you ever tried to visualize your hands… after closing your eyes? Previous studies had shown that we tend to underestimate our finger length increasingly from thumb to little finger. Researchers at Birkbeck, University of London,  made a new discovery after examing a 38-year-old woman born without a left arm. Your brains do not require visual or sensory input to represent your hands!

New Scientist reports:

For the first time, the perceived shape of a phantom limb has been measured. This should make it possible to learn more about how the brain represents what we look like.

The illusion of a phantom limb can kick in after an amputation or in people missing limbs from congenital disease. The result is the sensation that the limb is, in fact, present.

One theory suggests people with phantom limbs take cues from those around them to work out what their missing body part looks like. Another theory is that the sensation of an invisible limb reflects brain activity in regions that map our body in space.

To clarify the sensory origins of phantom limbs, Matthew Longo at Birkbeck, University of London, and colleagues enlisted the help of CL – a 38-year-old woman born without a left arm, who periodically feels she has a phantom hand. They asked her to place her right hand beneath a board and indicate where she believed her fingertips and knuckles were. She then repeated the exercise imagining that her phantom left hand was beneath the board instead.

Previous studies have shown that we tend to underestimate our finger length increasingly from thumb to little finger. This mirrors differences in the sensitivity and size of areas in the brain’s  somatosensory cortex that are thought to represent each digit, probably by making use of visual, mechanical and tactile feedback. The thumb is represented by a larger area of the cortex than the little finger.

As expected, CL reported these characteristic distortions when indicating the dimensions of her right hand. But she made the same errors when describing her phantom hand, implying she perceives both hands in the same way (Clinical Psychological Science).

That suggests there is “some structural representation in the brain of a body part that has never existed”, says Patrick Haggard at University College London, another member of the team. This implies that the somatosensory cortex does not require visual or sensory input to represent a body structure.

Understanding how the brain perceives the body could have broader implications. Longo says there are a few studies showing that people with eating disorders may inaccurately judge the size of their body from tactile feedback. Those results suggest there may be some relation between somatosensory representations of the body and our conscious feelings of what our body is like,” he says.

Read more about previous research that demonstrated through hand projections how faulty body perceptions work in  anorexia and other eating discorders:

Hand projections demonstrate how anorexia works 

Here’s a fun experiment: stop what you’re doing and use your hands to count to ten. Done? Good. Now remember how you did it, because we’re about to analyze your technique; as it turns out, how you count with your hands may say a lot more about you than you think.

So, how do you count?

Many cultures use some variation of what psychologists call the “closed fist method”, wherein one starts with a closed fist, and begins counting by unfurling the fingers of his or her hand. But the similarities end there.

“The degree of cultural diversity in finger counting… has been grossly underestimated,” write psychologists Andrea Bender and Sieghard Beller in the latest issue of  Cognition.

FULL ARTICLE:

What finger-counting says about you and your brain

Dr Oz: 'left-handed people are smarter'

Are left-handed people smarter than right-handed people?

“Well, in a way, left-handed people are smarter, and I’ll tell you why,” Dr. Oz says. “Left-handed people can deal with more incoming information that doesn’t come in an organized way.” Dr. Oz says this is because of the way the brain develops when a baby is in its mother’s womb. “The left brain normally controls your right side, which is really powerful,” he says. [In left-handed people], it allows the other side, the right brain, to become an equal partner.”

Because left-handed people can use both sides of their brain more readily, Dr. Oz says, they can process information coming into their brain in different ways more easily. “That’s why athletes do so well when they’re left-handed. And there are a lot of presidents who have been left-handed, and there are a lot of folks who, because they can deal with a lot of complicated issues at once, work pretty effectively,” he says.

But Dr. Oz says although you may write with one hand, parts of the body on the other side—such as an eye—can still be dominant. To determine which eye is dominant, Dr. Oz says to cut a pencil-sized hole in a piece of paper and hold it away from your face. Look through the hole at an object using only your right eye, then only your left. Dr. Oz says whichever eye you can still see the object through the hole with is your dominant eye.

Dr. Oz says many people are dominant with one eye and dominant with the opposite hand. “There are lots of different reasons you want to know [which eye is dominant]. If you were playing sports, it’s sort of helpful,” he says. “But folks actually use their different parts of their brain very differently, and it’s sort of cool to understand how it all comes up.”

A FEW MORE FACTS ABOUT LEFT-HANDEDNESS:

While left-handedness (ranging from moderate through strongly left-handed) is found in approximately 10% of the population

• Four out of five (80%) original Macintosh computer designers were left handed;

• Five out of the last seven (71%) US presidents were left handed (Barack Obama’s runner-up – senator John McCain – is also a lefty);

• One out of four (25%) Apollo astronauts – who were all selected e.g. by their high intelligence – was left handed;

Mensa International  (the largest and oldest high-IQ society in the world) claims that 20% of their members are left handed;

• A 1988 study reported: 16.9% of 266 United States Chess Federation players being left-handed or ambidextrous (included in the sample were e.g. 138 male Chess Masters, 18.1% was left-handed or ambidextrous).

[tweetmeme source=”handresearch” only_single=false] Left-Handers Day was first celebrated on August 13th, 1976 by Lefthanders International). The purpose of the day is to both celebrate left-handedness and raise awareness of the unnecessary biases against left-handers. The holiday is still proudly observed by lefties every year on August 13th. Enthusiastic supporters may organize lefty vs. righty sports matches and encourage right-handers to try using left-handed products to experience the same awkwardness they are too often forced to endure. A few more lefty facts

What causes left handedness?

The factors that contribute to handedness, are not completely understood. Both genes & environmental factors are involved, but the brains play a significant role as well. The left brain, which controls the right hand, is dominant in most people and is the center of logical thinking. But in left handers is the right brain more dominant. And because the right brain is more associated with art, creativity, phantasy & emotional expression – the might explain why research has indicates that left handedness is about twice as often seen in artists than in the general population.

Where does left handedness excel?

Typical fields where left handers relatively often excell are:

>> POLITICS: 

7 Out of the last 14 US presidents were left handed, and Barack Obama’s final ‘rival’ – senator John Mc Cain – is left handed; in 1992 all three presidential candidates (George H.W. Bush, Bill Clinton & Ross Perot) were left handed!

>> SPORTS: 

Left-handers excel particularly in tennis, baseball, swimming and fencing.

>> SCIENCE:

Leonardo da Vinci, Michelangelo & Isaac Newton were left handed, and 1 in 4 Apollo astronauts were left handed.

>> HISTORY:

A few other exceptional historical ‘lefties’ from various fields are:

Julius Caesar, Fidel Castro, Charlie Chaplin, Robert DeNiro, M.C. Escher, Mahatma Gandhi, Bill Gates, Alexander the Great, John McEnroe, Niccolò Paganini, Rembrandt van Rijn, Romario de Souza Faria, Mark Twain.

SUGGESTION FOR FURTHER READING:

• Left handedness in the news! 
• 7 out of the last 14 US presidents were left handed! 
• Left handed people are intelligent & creative!
The origins of left handedness!
Left handers day 2009!

Hand projections demonstrate how anorexia works

[tweetmeme source=”handresearch” only_single=false] 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!

Will Your Man Cheat …?

[tweetmeme source=”handresearch” only_single=false] What if you could find out if your man is at a higher risk for infidelity before you married him? Dr. Phil and his panel of medical experts discuss the new science behind a cheater’s brain and what can be done if your loved one is at a higher risk. Author of Change Your Brain, Change Your Body, Dr. Daniel Amen, author of Insatiable Wives, clinical psychologist Dr. David Ley, Claremont University’s Dr. Paul Zak and author of The Male Brain, neuro-psychiatrist Dr. Louann Brizendine explain how you can discern a man’s risk for infidelity and the treatment options to lower his risk.

Dr.Phil.com presents a 4 item list of physiological indicators that your han is at a higher risk for cheating:

  • Length of ring finger compared to pointer finger: The length of a man’s ring finger is linked to testosterone in utero and during puberty. A longer ring finger means more testosterone, and the increased likelihood of a greater number of sex partners and a higher risk of cheating.

  • Facial symmetry and size of jaw: If one side of a man’s face matches the other side, is symmetrical, the more it is an indicator to women that that man has high genetic value. Men whose faces are more [symmetrical] are more likely to have more partners because more women want to have their children.
  • Size of penis: If a male is well-endowed, that means more testosterone and a higher risk of cheating.
  • Brain injuries: Men with a history of engaging in impact sports like football or martial arts, or men who’ve had a history of concussions are at a higher risk. Also, men with disorders like ADD or bipolar disorder have low pre-frontal cortex activity or hyper-frontal activity, which could mean less ability to stop impulsive behaviors, like cheating.

By the way, did you know that… Casanova had the long ring finger!

 SUGGESTION FOR FURTHER READING:
BBC Test: finger length & sex I.D.!
Finger length & Cupid’s science!
The science of gaydar: finger length & sexual preference!
What they say about men with long ring fingers!

VoiceAmerica & Kenneth Lagerstrom present new radio show: Your life is in your hands!

TRIBUTE: THE HAND LINES & PALMAR CREASES

[tweetmeme source=”handresearch” only_single=false] This week’s episode (June 1) of VoiceAmerica radioshow “Your Life is in Your Hands” was featured with the presence of UK hand analyst Lynn Seal, who talked with host Kenneth Lagerström about ‘lines of the hands’.

During the hour various aspects of the hand lines were discussed, including: the mystery of the ‘palmar flexion creases’, the prenatal development of the (major) hand lines in the early life of the embryo, line variations among ethnic populations, the differences between hand lines in the left and right hand, and how the hand lines can be used for different purposes in palmistry. Lynn explained very well that in time the hand lines can show significant changes; this simple fact might explain why the validity of ‘future predictions based on the hand lines’ are even disputed from within the palmistry community!

The podcast of the show is available at ‘Palmistry – The Lines of The Hand‘.

Let’s take a closer look on some basic characteristics of the hand lines. How can we learn to understand them properly?

In modern palm reading (cheirology) the hand lines are not used for predicting the future; contrary the hand lines are recognized as ‘energy flows’ reflecting process in the body and the brain which related the various aspects of an indvidual, including temperament, personality & and interpersonal functioning.
Palmistry: the major hand lines & palmar creases.

HAND LINES IN THE HAND OF AN EMBRYO

Contrary to what many believe, the development of the hand lines does not directly relate to the movements of the hands. For example, the three major hand lines (life line, heart line and hand line), start developing in the hand of the little embryo in the 2nd month of gestation – while the first hand movements do not occure before the 2nd half of the third month.

Another indication is provided by the fact that usually the ‘passive’ hand (= left hand for righthanded people) shows more hand lines then the ‘active hand’ (= right hand for righthanded people). And often the hands of people who are active in jobs that require a lot of manual work, show less palmar lines than those who are active in jobs that are not featured with the use of the hands (such as social work).

After about 7 weeks the life line starts developing in the hand of the embryo.
The hand of a 7 week old embryo.The hand of a 7 week old embryo after 48 days.

WHAT DO THE HAND LINES REVEAL?

Despite the fact that many palmists around the world – especially in Asia – still claim that the lines in the palm or our hands reveal information about our future, the truth is that within the global palm reading community there appears to be a growing number of debaters who actually question the validity of this claim.

While traditional palmistry has merely been a matter of using the hand as an occult ‘tool’ – focussed on making (future) ‘prediction’; in the 20th century modern palm reading became more focussed on the issue of understanding human nature, by studying the psychological- & spiritual life of individuals.

The most frequently asked question is probably: “what do my hand lines reveal?” Interestinly, the answer might actually depend on the person who is faced with this question! For example, a traditional palmist might point to your future, a modern palm reader might point of your brain, and a scientific hand analyst … might point to your genes!

14 Palmar creases: an overview of the most common hand lines.
Palmar creases: an overview of the most common hand lines.
SUGGESTION FOR FURTHER READING:
What’s the story of the notorious ‘simian crease’?
And are the ‘Sydney line’ & the ‘simian line’ related?

Professor John T. Manning explains how finger length relates to testosterone & athletic behavior.

Last year NextNature reported that job interviews might get replaced by brain scans within five years. But our bodies presents another biometric measure that correlates with social ability – it’s in the ratio of your fingers! John T. Manning, professor in psychology, has demonstrated how his ‘controversial’ academic theory can be applied to individuals.

Academic science has developed a new theory about how finger length relates to human biology & behavior. A significant part of theory is focussed on the so-called: ‘2D:4D digit ratio’, which concerns the full length ratio of only two fingers: index finger vs. ring finger. In women the length of both fingers is usuallly about equal (2D:4D digit ratio = 1.00), while in men the ring finger is usually slightly longer (digit ratio = 0.98): a tiny sex difference.

NOTICE: This tiny sexe difference has been confirmed among many ethnic populations around the world, but one should also keep in mind that the finger length differences between ethnic populations are often larger than the finger length differences between males and females.

FINGER LENGTH & SOCIAL ABILITY

The earlier NextNature report described that brain scans can recognize tendencies towards autism – it concerns a matter of ‘hypermasculinity’ of the brains. The same is true for the ‘2D:4D digit ratio’: multiple international studies have revealed that people with autism usually have typical male-like finger length ratios (0.94 or lower). However – maybe less surprizing – the typical male-like low 2D:4D ratio also relates to athletic ability!

FINGER LENGTH & ATHLETIC ABILITY

Professor John T. Manning of the University of Liverpool (School of Biological Sciences, Liverpool, UK) explains the link between finger length & athletic ability as follows (in the BBC’s ‘Secret of The Sexes‘):

“Our fingers have information about how much testosterone and how much oestrogen we’ve been exposed to in the whomb. So, the longer one’s ring finger relative to one’s index finger, the more testosterone you’ve had. And that testosterone has an effect on the brain, and on the body. If a boy has a large amount of testosterone before birth, he is likely to be born with a very efficient heart and vascular system.”

“So the longer one’s ring finger relative to one’s index finger, the faster one can run.”

The BBC’s “Secret of The Sexes” confronted the ‘finger Professor’ with six athletes – all 5000 meter specialists, and asked him to “predict” the outcome of the race based on finger length only. Actually, the BBC provided Manning photocopies of the athletes hands, and in return Professor Manning risked his reputation by providing the results of a race that had yet to be run.

The outcome of the experiment is unvealed “LIVE” in the video. And surprizingly… the theory appeared to be pretty accurate in practice. After Manning & the athletes are controfonted with the results Manning summarizes:

“… We’ve got four out of six right, but the two that are wrong were kind a quite close.”

The winner of the 5000 meter race responds:

“I thought… that finger thing is bullox because there are so many variables… I am very impressed”.

Coincidence?

Manning’s theory was also confirmed by the results of various studies e.g. on endurance running & sprinting speed. And in another likewise experiment finger length correctly predicted the outcome of a 100 meters race with 5 young sprinters.

FINGER LENGTH & OTHER LIFE ISSUES

In his second book – titled ‘The Finger Book‘ – Professor Manning explains that because of the prental link with the androgens (testosterone & oestrogen), finger length studies have generally shown consequent sensible correlations with a rainbow of life issue. The tiny sex difference appears to be highly revealing, for hundreds of studies the ‘2D:4D digit ratio’ appears to correlate with a wide range of topics that are usually also known for a typical male-female difference, including: musical ability, personality, health, and even sexual preference. More articles & reports are available at: finger length & digit ratio news.

The following three videos present more materials from the episode ‘Brain Sex’ of the BBC’s “Secrets of The Sexes” – that relate to finger length – including social ability: in the second and third video Manning explains how finger length is related to in respective: performance in spatial-visual tasks and another typical sexe-related aspect of personality: the ability to empathize!

NOTICE: You can see the complete movie (three episodes) at: CORNEL1801.

HOW TO MEASURE DIGIT RATIO?

NOTICE: Measuring the ‘2D:4D digit ratio’ is really a matter of measuring the full length of both fingers. Two additional tips to avoid: 1 – don’t try to ‘judge’ the 2D:4D digit ratio with bare eyes only (conscientious measurment + calculation is a necessity) 2 – one can not find the ‘2D:4D digit ratio’ from the back of the hand, nor the tips of the fingers only.

Source picture: University of Cambridge.
University of Cambridge: how to measure the 2D:4D digit ratio.

IS THIS THE NEW ‘PALM READING’?

In 2008 Professor Chris McManus of the University College London (Psychology and Medical Education) characterized Manning’s finger research as follows:

“Chiromancy, the notorious pseudoscience that Sir Walter Scott bracketed with physiognomy, astrology and “other fantastic arts of prediction”, has for two decades been creeping back into scientific favour. And John Manning is its high priest. In The Finger Book, he [Manning] writes: “I believe that the pattern and nature of our decline in middle life and the disease which will eventually lead to our death, is dependent to a large extent on our experiences as a foetus”, a phrase that could almost have been written by Cheiro, the early 20th-century society palmist.”

Because of the obvious association with the divination aspect of palmistry (which is still very popular in various countries such as India & Pakistan), the issue of the ‘2D:4D digit ratio’ will probably continue to have a controversial status.

More ‘Next Nature’ reports? – See: www.nextnature.net.
More ‘2D:4D digit ratio’ reports? – See: www.handresearch.com.