Monday, February 02, 2009
Research has now shown exactly how this works - by creating a tactile sensor with "fingerprints" and one with a smooth surface, and measuring the difference between the two.
Interestingly, "the researchers noted that their artificial fingerprints worked only if the direction of motion was perpendicular to the direction of the ridges. Thankfully, the whorls, arches, and loops on real human fingertips mean that swiping in any direction will activate the filtering effect. This could imply that the contours of our fingerprints are patterned to optimize texture perception"
I wonder about this, because the ridges of arches can be relatively 'horizontal', i.e. in one direction only. Does this mean that people with arches may have a lower sensitivity when swiping the finger in the same direction as the ridges? That would be an interesting experiment.
Saturday, August 09, 2008
Police now have the ability to analyse the traces of cannabis, cocaine and other drugs, or explosives, in a fingerprint itself.
The new technique reveals, in extraordinary detail, the chemical compounds that make up the print and could also find medical uses, since tiny traces of chemicals at our fingertips could signal the presence of a disease or an illness."
"Researchers can detect minute traces of compounds - marked as dots on the print - that were on the fingertips of the person who left the print."
Tuesday, February 05, 2008
First up, he said, are palm prints. The FBI has already begun collecting images and hopes to soon use these as an additional means of making identifications. Countries that are already using such images find 20 percent of their positive matches come from latent palm prints left at crime scenes, the FBI's Bush said.
You don't have to be a criminal or a terrorist to be checked against the database. More than 55 percent of the checks the FBI runs involve criminal background checks for people applying for sensitive jobs in government or jobs working with vulnerable people such as children and the elderly, according to the FBI.
The ACLU's Steinhardt doesn't believe it will stop there.
"This had started out being a program to track or identify criminals," he said. "Now we're talking about large swaths of the population -- workers, volunteers in youth programs. Eventually, it's going to be everybody."
Wednesday, January 02, 2008
"To artists, and a few scientists, the hand is as revealing as the face in expressing temperament, heredity, life habits, glandular function. One such scientist, Dr. Charlotte Wolff, physician and psychologist, last week gave her second summary of findings in the science of chirology. In The Human Hand (Alfred A. Knopf, $3) she carried on her rescue of the hand from the hocus-pocus of palmistry and fortunetelling, gave laymen some interesting reading as well."
Read the full article
Thanks to Lynn Seal for digging this article up.
Tuesday, November 06, 2007
source: dailymail.co.uk, telegraph.co.uk
Tuesday, August 28, 2007
"A study of how baboons gesture with their hands suggests gesturing may have been a precursor to human language, scientists say.
The findings could help to explain why humans often gesture with their hands, and particularly the right hand, when they speak.
The right hand is controlled by the brain's left hemisphere, which is the source of most linguistic functions.
Scientists believe communication by hand probably existed in apes 30 million years ago and was a forerunner to spoken and written language.
French researchers Adrien Meguerditchian and Professor Jacques Vauclair studied a particular hand gesture in 60 captive baboons.
The gesture consists of quick and repetitive rubbing or slapping of the hand on the ground, and is used to threaten or intimidate others.
The researchers, from the University of Provence, say this motion "might be comparable in humans to the slap of ... one hand toward the palm of the other hand".
For the study, which is published in the journal Behavioural Brain Research, the researchers observed this gesture as it occurred naturally.
They also triggered it by having a human abruptly shake his head and then glance at a baboon. Head shaking is another threatening move in the ape and monkey world, which includes all sorts of communicative gestures.
"A nonhuman primate can effectively raise an arm to ask a social partner to groom it ... give another a little slap as an invitation to play, touch furtively the hand or genitals of another to greet it, slap the ground to threaten," the researchers say.
Among the baboons in the test group that favoured a certain hand, 78% were right-handed and tended to gesture with this hand. Other studies have shown that most human babies and deaf individuals also communicate with their right hands.
"There is little chance that our [primate] cousins will evolve language skills in the near future," the researchers say.
"Monkeys and apes and their specific communication systems result from other evolutionary roads than those of humans ... It is very unlikely that the natural selection for primate species will reproduce exactly the same phylogenetic path that gave linguistic skills to humans."
William Hopkins, a US psychology professor at Berry College and an expert on the evolution of brain development in primates, says:
"I agree with the findings and think this is a very good and interesting paper. In many ways the results are nearly identical to those we have previously found in chimpanzees."
He explains that both chimps and baboons seem to use right-hand gestures for communication. This suggests the brain is asymmetrical when it comes to language, meaning that the left hemisphere tends to dominate.
"It will be interesting to see whether the asymmetries in hand use seen in the baboon link at all to brain asymmetries as we have found in the chimpanzees," Hopkins adds.
Source: News in Science
Wednesday, April 18, 2007
Shen Xiaojing says that she was born with very big feet and they were twice as big as her contemporaries when she was 4 years old. She says that she has been unable to buy herself suitable shoes and always wears shoes made by her mother. When she was in primary school, her schoolmates laughed at her and called her "big feet Shen". At that time, her big feet surpassed in size any male adult's feet in her county.
Recently, she met with a local news reporter who interviewed her and measured her feet. Her right foot is 32 cm in length and 12 cm in width (The average foot length for a Chinese girl is between 22 and 24 cm). Her feet bear no similarity with her parents and both of them have average sized feet.
Her feet have kept growing over the past 20 years. Her family has spent much money in medical bills trying to ascertain the cause of her "strange condition," but have found no answers. "It was fortunate that my feet finally stopped growing last year," she told the reporter.
Although she is tall and slim with good looking features, she has frightened away all the prospective mates arranged by her parents. Last year, a friend introduced her to a man who was divorced and eight years older than Shen. At the beginning they talked with each other happily, however, he refused Shen after he saw her big feet. Traditionally, men like women with small feet in China.
Shen told the reporter, "My family is very poor and my brother is working in a restaurant to earn money to cover my hospital bills. He often calls me and encourages me to be strong and live happy. I would never disappoint him." In addition, she said in the interview, "I hope I can go to work in a big city like Beijing and Shanghai and see the outside world. I also hope I can earn a lot of money to help my parents live a better life."