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:
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.
HANDS & IQ – How to recognize a smart hand: 3 – Dr Oz says: ‘in a way, left-handed people are smarter’!
January 24, 2011
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:
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!
Left-handers excel particularly in tennis, baseball, swimming and fencing.
Leonardo da Vinci, Michelangelo & Isaac Newton were left handed, and 1 in 4 Apollo astronauts were left handed.
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:
July 20, 2010
[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!
[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.
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.
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.