Tag Archives: hand

The FDA warns public not to use potentially toxic hand sanitizers from Eskbiochem

The Food and Drug Administration (FDA) has issued a warning for the public not to buy or use hand sanitizer produced by a particular company as it contains methanol.

Image credits Harvey Boyd.

Methanol, the simplest molecule in the alcohol family, can be toxic when absorbed through the skin or ingested. According to the FDA, certain hygiene products manufactured by Eskbiochem SA de CV in Mexico can potentially contain methanol. As such, the institution warns people not to use them.

“Substantial exposure” to methanol can cause nausea, vomiting, headache, blurred vision, permanent blindness, seizures, coma, permanent damage to the nervous system or even death, according to the FDA.

The bad alcohol

“Consumers who have been exposed to hand sanitizer containing methanol should seek immediate treatment, which is critical for a potential reversal of toxic effects of methanol poisoning,” the FDA says in a statement.

“Although all persons using these products on their hands are at risk, young children who accidentally ingest these products and adolescents and adults who drink these products as an alcohol (ethanol) substitute, are most at risk for methanol poisoning.

The warning extends to nine products of the company, which the FDA found methanol in samples of. These are All-Clean Hand Sanitizer, Esk Biochem Hand Sanitizer, CleanCare NoGerm Advanced Hand Sanitizer, Lavar 70 Gel Hand Sanitizer, The Good Gel Antibacterial Gel Hand Sanitizer, Saniderm Advanced Hand Sanitizer and three varieties of CleanCare NoGerm Advanced Hand Sanitizer.

Sampling revealed between 28% to 80% methanol and no ethyl alcohol (the last one is the one in beer or other drinks) in some of these products. “methanol and no ethyl alcohol” the agency adds. Products should contain ethyl alcohol (ethanol), isopropyl alcohol (isopropanol), or benzalkonium chloride to be marketed as hand sanitizers.

People who apply the products to their hands are at some risk for methanol poisoning, but the greatest risk comes from ingesting methanol. The FDA notes that children tend to accidentally ingest such products, while others (teens and adults) will sometimes drink them as an alcohol substitute.

If you’ve used these products, seek medical treatment immediately, the FDA advises. Any remaining products should be disposed of as well.

The agency has contacted Eskbiochem to ask them to remove the products from the market but the company has yet to take action, prompting the current public warning.

Methanol is dangerous because our bodies break it down into formic acid, which is toxic to our cells. Around 56 grams of methanol are, on average, the lethal dose for an adult human. Methanol poisoning is most usually associated with unlicensed alcohol production, where methanol isn’t properly removed during the distillation process.

Waving away mosquitoes teaches them to stop bothering prey

A female mosquito dining at a fancy… human?
Source: Pixabay/skeeze

Mosquitoes rely on smell to choose victims. In a new study published in Current Biology, mosquitoes learned to associate smells with vibrations mimicking human hand movements. After subsequent exposures to the same smell, the arthropods avoided the respective odor. This behavior suggests that the insects learned that certain scents were associated with a near-death experience.

The smell of fear

Mosquitoes, these tiny, annoying vampires, bother everyone from birds to humans. They are not just terribly vexing, but dangerous as well. Even though the word ‘mosquito’ comes from Spanish and means ‘little fly’, the insects are not innocent at all. Mosquitoes are considered the deadliest animals on Earth, causing 725,000 deaths per year, according to a 2014 World Health Organization survey. Malaria, a mosquito-borne infectious disease, killed 445,000 people in 2016, states WHO.

These alarming numbers are the main reason why scientists are now trying to come up with different methods to reduce mosquito bites.

Previously, researchers discovered that each mosquito species shows a proclivity towards a certain type of host animal, even towards distinct individuals within those species. Unfortunately, the exact mechanisms through which this insect chooses its prey are still unknown. For example, generalist mosquito Culex tarsalis primarily torments birds in the summer but feeds on both mammals and birds in the winter.

Researchers at the University of Washington conducted an experiment to see if mosquito preferences could be learned. The team, led by Jeffrey Riffell, employed mosquitoes, rats, chickens and a machine named the “vortexer”. Scientists first presented the insects with an animal smell — a rat, for example. Next, the vortexer was used to inflict small mechanical shocks on mosquitoes.

A mosquito in the “vortexer” machine, which simulates swats. (Image: Kiley Riffell)

The following step was to assess if the mosquitoes learned something. Two groups of mosquitoes took part in the study: a control group of untrained mosquitoes and a group of previously trained ones. Researchers discovered that trained mosquitoes did not attack the rats, as the untrained ones did. When scientists repeated the experiment — but this time with chickens — they observed that the Aedes aegypti mosquitoes encountered some difficulty acquiring avian odors. The reason might be that the Aedes aegypti mosquitoes predominantly suck human blood, so they would be inclined to learn mammal smells faster.

“Once mosquitoes learned odors in an aversive manner, those odors caused aversive responses on the same order as responses to DEET, which is one of the most effective mosquito repellents,” said Riffell in a statement. “Moreover, mosquitoes remember the trained odors for days.” he added.

Scientists wondered how the small mosquito brain could process such a large amount of information. One answer came to mind: dopamine, a neurotransmitter that is frequently used in learning processes (especially in remembering with the help of good or bad stimuli) by mammals and insects alike.

The team had one more thing to do: to prove their theory right. So, they genetically engineered mosquitoes that lacked dopamine receptors and glued them to a rack in order to monitor their neuron activity when introducing them to different odors. The researchers discovered that neurons were less likely to fire when presented various smells due to their inability to process dopamine.

A mosquito glued to a 3D-printed rack. (Image: Kiley Riffell)

“By understanding how mosquitoes are making decisions on whom to bite, and how learning influences those behaviors, we can better understand the genes and neuronal bases of the behaviors,” said Riffell. “This could lead to more effective tools for mosquito control.”

So, if a mosquito is troubling you, feel free to wiggle your hands at it. You might not kill it, but there is a good chance it will leave you alone.

Child’s brain rewires following double hand transplant 

This is the incredible story of Zion, the first quadruple amputee child in whom researchers observed massive brain reorganization before and after the hand transplant.

Zion was only two years old when he lost both his hands and feet due to a grave generalized infection. At the age of four, his mother donated one of her kidneys to him, allowing doctors to consider him as a candidate for a bilateral hand transplant. Zion had already been on immunosuppressant drugs.

Hand transplants in children are rare and difficult to perform, due to the extremely small size of the vessels and nerves that need to be reconstructed. Zion’s surgery was the first pediatric hand transplant in the world. The medical team included twelve surgeons, divided into four smaller teams that had to find and label all the structures that were to be sewn together. The whole procedure lasted 11 hours.

Now, Zion can do all the things he always wanted to: feed himself, scratch his nose, wave goodbye, shake hands, even play baseball. One special thing he is really eager to do is to write, with his own hands, a letter to the parents that had donated their child’s hands to him.

How it all began

The researchers recorded the child’s brain activity two years before the surgery, and then monitored the way his brain rewired after the amputation — a process called massive cortical reorganization (MCR).

“We had hoped to see MCR in our patient, and indeed, we were the first to observe MCR in a child. We were even more excited to observe what happened next — when the patient’s new hands started to recover function. For our patient, we found that the process is reversible.” said Gaetz.

For each part of the body that transmits sensitive information to the brain, there is a specific region of the cerebral cortex that is activated. This biological phenomenon is known as somatosensory representation.

“We know from research in nonhuman primates and from brain imaging studies in adult patients that, following amputation, the brain remaps itself when it no longer receives input from the hands,” said first author William Gaetz, PhD. “The brain area representing sensations from the lips shifts as much as 2 centimeters to the area formerly representing the hands.”

Zion, age 10. Credit: Children’s Hospital of Philadelphia.

Magnetoencephalography (MEG) is a neuroimaging technique that measures the magnetic activity of elected areas in the brain. Using MEG, scientists studied the location, timing, and strength of Zion’s reactions to sensory stimuli (differently sized monofilaments) applied to his fingers and lips. Four such MEGs were performed in the year following the transplant, using five children the same age as Zion as controls.

“At visits 1 and 2, index fingertips were insensitive to tactile stimulation with even the largest monofilaments. At visits 3 and 4, the patient was able to sense light touch on the fingertips,” the authors wrote in the paper published in the journal Annals of Clinical and Translational Neurology. 

The first two times, researchers found that the signal transmitted from Zion’s lips was recorded in the hand area of the cortex, but with a 20 milliseconds delay, compared to controls. At the latter two MEGs, the lip stimuli had returned to the lip-designated area, indicating that the brain map was regaining its previous configuration but with higher-than-normal signal strength.

“The sensory signals are arriving in the correct location in the brain, but may not yet be getting fully integrated into the somatosensory network,” said Gaetz. “We expect that over time, these sensory responses will become more age-typical.”

Gaetz added, “These results have raised many new questions and generated excitement about brain plasticity, particularly in children. Some of those new questions include, what is the best age to get a hand transplant? Does MCR always occur after amputation? How does brain mapping look in people born without hands? Would we see MCR reverse in an adult, as we did in this patient? We are planning new research to investigate some of these questions.”

The teams from the Children’s Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania published their findings in the Annals of Clinical and Translational Neurology on December 6th, 2017.

Designed for astronauts, the RoboHand can double your hand’s strength — and soon, it will be available on Earth

The RoboGlove, a NASA and General Motors joint design intended to help astronauts perform heavy duty repairs, will become available on Earth. The technology has been licensed to Sweedish medical technology firm Bioservo Technologies.

GM principal engineer for robotics Marty Linn wearing the RoboGlove shakes hands with Robonaut 2.
Image credits NASA/GM

This glove is the product of a nine-year collaboration between GM and NASA, who partnered for the Robonaut 2 project — a humanoid robot meant to assist ISS astronauts with maintenance and repair works, which was launched in 2011. The technology that went into creating the robot’s hands, designed to be as dextrous and versatile as a human’s hands, were further developed into the RoboGlove.

This wearable tool is equipped with a network of pressure sensors that can detect when the user is holding an object and a series of actuators and synthetic tendons to apply extra grip.

Gif via youtube

“An astronaut working in a pressurized suit outside the space station or an assembly operator in a factory might need to use 15 to 20 pounds of force to hold a tool during an operation,” said NASA in 2012 while the glove was still ion development. “But with the robotic glove they might need to apply only five to 10 pounds of force. The roboglove halves the amount of force needed”

The device is powered by a battery pack worn on the user’s belt and lends itself well to industries where workers have to put in sustained effort over long periods of time — such as assembly workers, manual laborers, and even surgeons.

Gif via youtube

Kurt Wiese, vice president of General Motors Global Manufacturing Engineering, said in a news release:

“The successor to RoboGlove can reduce the amount of force that a worker needs to exert when operating a tool for an extended time or with repetitive motions.”

No timeframe for the glove’s deployment has been given yet, but this gripping technology is joining a growing number of products designed to make workers’ activities safer and more efficient. Companies such as Hyundai, BMW, and Panasonic have all announced they’re working on exoskeleton prototypes aimed at helping manufacturing workers.

This illusion can hack your brain into feeling the space around you

Neuroscientists at the Karolinska Institute in Stockholm, Sweden have found that they can make people “feel” the space immediately around them. The participants describe the sensation like a “force field” surrounding them.

Image credits Amely/Pixabay

Our brains have developed to be aware not just of our body’s position in space, but also of the objects in our immediate vicinity known as the peripheral space. This ability allows us to effectively grasp or interact with the objects that surround us and serves to protect us from harm.

Imagine you’ve just finished lunch with a friend in a restaurant. As you’re getting up to leave, a waitress passes through your peripheral vision. You’ll instinctively move in such a way as not to collide with her; your sense of peripheral space has saved you from getting doused in scalding hot coffee.

The first evidence of this phenomenon appeared in the late 1990s. Researchers at Princeton University studied the brains of monkeys and found that neurons in the parietal and frontal lobes generate electric signals not only when an object touched their body, but also when it came close enough to any part of their bodies. When stimulating these neurons, the monkeys adopted defensive movements — reflexively moving their arms into a protective posture.

These experiments were never repeated on humans, but patients suffering from strokes in the right posterior parietal lobe report that they can’t sense peripheral stimuli on the left side of their bodies but “sense” things further away on that side.

“This suggests that there is a representation similar to those found in monkeys in the human brain,” says Arvid Guterstam of the Karolinska Institute in Stockholm, Sweden.

To test this theory, Guterstam and his colleagues employed the rubber hand illusion to trick humans into actually feeling our peripersonal space. This experiment involves hiding a volunteer’s hand from sight then stroking it with a paintbrush. The experimenter simultaneously strokes an adjacent, visible rubber hand during this time, at the same speed and in the same spot on the rubber and real hand. After a few minutes, the participants start feeling the touch on the rubber hand, as if it were their own. This only works as long as the two hands are close enough together.

For the new study, the team recruited 101 adults but instead of brushing the rubber hand directly, they moved the brush above it as they touched the real hand. The volunteers thus felt the stroke on their body but saw the brush move in mid-air, about 10 centimeters above the rubber hand.

For the most part, volunteers reported feeling a “magnetic force” or a “force field” between the paintbrush and the rubber hand. They describe it as the brush hitting an invisible barrier. They also reported feeling that the rubber hand belonged to them.

“We can elicit this bizarre sensation of there actually being something in mid-air between the brush and the rubber hand,” says Guterstam.

Here too, distance seems to be a factor. When the brush was held more than 30 or 40 centimeters above the rubber hand, the illusion disappeared. Placing an opaque metal barrier between the rubber hand and the brush also had this effect. Guterstam speculates that this happens because the barrier makes it impossible for the hand to reach up and grasp anything, or for anything to hit the hand; in essence, it limits the perceived peripersonal space of the limb.

“This is a wonderful study,” says Michael Graziano, who conducted the 1990s experiments. “For decades, the neuroscience of the parietal and frontal lobes has filled in our knowledge of the special margin of safety, or buffer zone, around the body. Now we have a clever way to get at the phenomenon through an illusion that is easy to implement in the lab.”

The full paper, titled “The magnetic touch illusion: A perceptual correlate of visuo-tactile integration in peripersonal space” has been published online in the journal Cognition and is available here.

For the first time in history, researchers restore voluntary finger movement for a paralyzed man

Using two sets of electrodes, scientists have successfully restored finger movement in a paralyzed patient for the first time in history. The results could be the starting point to developing methods that would allow people around the planet to regain limb mobility.

Four years ago, Ian Burkhart lost the ability to move his arms and legs. Now thanks to a neural implant and electrodes on his forearm, he's able to move his wrist, hand, and fingers. Image credits Ohio State University Wexner Medical Center/ Batelle

Four years ago, Ian Burkhart lost the ability to move his arms and legs. Now thanks to a neural implant and electrodes on his forearm, he’s able to move his wrist, hand, and fingers.
Image credits Ohio State University Wexner Medical Center/ Batelle

There are roughly 250,000 people living with severe spinal cord injuries in America alone — people who have to manage going through life with little or no mobility. One such man is 24 year old Ian Burkhart, who lost the ability to move or feel from the shoulder down in a diving accident four years ago. But, thanks to a team at Ohio State University, Ian became the first to regain control over his body. By using electrodes to bypass his damaged nerve pathways, the researchers allowed him to move his right fingers, hand and wrist.

“My immediate response was I want to do this,” said Ian after the four-hour procedure of inserting the electrodes into his brain . “If someone else was in my place, with the possibility of changing my life and people like me in future, I would hope they would agree.”

The first step was to implant an array of electrodes into Burkhart’s left primary motor cortex, an area of the brain that handles planing and directing movements. Signals generated in his brain were recorded and fed through a machine learning algorithm. It took almost 15 months of three training sessions each week to teach his brain to use the device. But finally, the software started to correctly interpret which brain waves corresponded to which movements.

Now, when Burkhart’s brain emits the proper signals, the implant sends these impulses through wires to a flexible sleeve — lined with electrodes — placed around his wrists to stimulate his muscles accordingly.

Image via giphy

The researchers tested Burkhart’s ability to perform six different hand, wrist and finger movements. An algorithm determined that Burkhart’s first movements were about 90 percent accurate on average.After his muscles got some exercise and improved their strength, Ian successfully poured water from a bottle into a jar and then stirred it. He was also able to swipe a credit card and even play some Guitar Hero.

The team notes that in its current form, the technique is highly invasive, meaning it might not be suitable for patients who are already in poor health or have compromised immune systems; They also point out that the device they used in this study allows for a greater range of movement than typically available neural bypass devices. Finally, the implant doesn’t restore a patient’s ability to feel — prosthetics might be able to solve that problem though.. Maybe someday the two technologies could merge to give patients both the ability to move and to feel.

Still, the study is a huge stepping stone. The way Burkhart was able to move his hand is simply mind blowing, and something considered impossible up to now. That could have big implications if the technology becomes used widely.

“Our goal was to use this technology so that these patients like Ian can be more in charge of their lives and can be more independent,” Ali Rezai, one of the researchers involved in the study, said in a statement. “This really provides hope, we believe, for many patients in the future.”

The team hopes to have their system refined and ready for wide-scale implementation in a few years.

The full paper, titled “Restoring cortical control of functional movement in a human with quadriplegia” has been published in the journal Nature and can be read here.

Muscles were contracted by guitar pegs, and a pendulum was used to swing the punch. Image: Andre Mossman/University of Utah

Did human hands evolved to pack a punch?

We humans arguably came to dominate the world thanks to our dexterous hands, which allow gripping tools and manipulating objects. An eccentric professor at University of Utah agrees, but with a twist. According to David Carrier there’s a secondary evolutionary driver that led our hands to reach their current shape and dexterity: fist punching. To illustrate his hypothesis, Carrier turned to a macabre experiment in which cadaver hands clenched in various positions, from open hand to a good old sucker punch fist, were bashed against a dumbbell. Carrier showed that a fist could handle the strike with double the force supported by an open hand before bones started to break.

Muscles were contracted by guitar pegs, and a pendulum was used to swing the punch. Image: Andre Mossman/University of Utah

Muscles were contracted by guitar pegs, and a pendulum was used to swing the punch. Image: Andre Mossman/University of Utah

More precisely, fishing wires were attached to the forearm’s tendons, then strapped to a guitar tuner at the other end. By turning the tuner, Carrier and colleagues could flex and position the individual fingers of the hand into any position. They settled for three positions:  clenched fist, loose fist or an open palm. The hands were put on a platform, then a pendulum swung the fists into a dumbbell. Force sensors were attached to both arm and dumbbell. Apparently, the strain on the  metacarpals was vastly reduced in a clenched fist position, compared to any of the other two.

“This is relatively strong evidence that there is a performance advantage,” Prof Carrier said.

“Whether or not natural selection ever acted on that advantage is something we can’t answer directly. But at the same time, given this evidence, you can’t argue that selection on aggressive fighting behaviour was not relevant.”

Of course, that’s not to say that Carrier disagrees with the overwhelming consensus: that hand evolution was shaped by tool use. Rather, he posits that fist fighting  “has to be included on the list of possible factors that could have influenced the evolution of the hand”.

Humans can safely strike under a clenched fist with 55% more force than with an open hand. Image: David Carrier/University of Utah

Humans can safely strike under a clenched fist with 55% more force than with an open hand. Image: David Carrier/University of Utah

Carrier says that no other primate can make a fist, and has at one time even gone as far as saying the human face also evolved to take a punch better. Actually, this isn’t the first time he’s tested this hypothesis. Back in 2012, ZME Science reported how Carrier devised an experiment in which different martial artists hit a punching bag, and found the structure of the fist provides additional support for the knuckles to transmit punching force. Again, he didn’t thought this was some evolutionary coincidence. His ideas are controversial. His experiments even more so, but he seems to be making an interesting point at least.

Most scientists aren’t convinced, though. Speaking for the Washington Post, Arizona State University’s Mary Marzke said:

“It also is surprising that the authors compared fist-punching with palm-slapping, instead of with striking by the heel of the palm,” Marzke told The Post. “The latter is well known to be very effective in fighting. It has the advantage of concentrating force over a relatively small area of the hand, an advantage that the author highlighted for the fist in an earlier study. The palm heel punch does not require hominin thumb and finger proportions.”

“At best, pugilistic encounters as an explanation for the evolution of the human hand remains just another story. There are many other behaviors that could be marshaled to explain the morphology of human hand bones,” said Brigitte Demes of Stony Brook University.

Speaking for the BBC, Dr Tracy Kimmel, a palaeoanthropologist at the University of Kent, acknowledged that Carrier’s work is sound, technically speaking, but the findings can’t support the hypothesis. Instead, she argues that there’s strong evidence that  our hands evolved to manipulate tools, considering “fossil evidence of tools goes back more than three millions years, and aligns with changes to hominid anatomy.” Everything else, is secondary.

Scientists find 1.85 million year old human-like bone

Anthropologists have discovered the oldest known fossil of a bone resembling that of humans; the 1.85 million year old bone is the oldest evidence of a ‘modern’ hand and suggests that ancient humans may have been much larger than previously thought.

The hand is one of the critical features distinguishing humans, and even a 3.6 cm(1.5-inch), two-million-year-old fragment provides valuable clues. Image credits: M. Domínguez-Rodrigo.

A key feature that distinguishes humans from other species is the ability to create and use tools. But in order to be able to create and use the tools, you need not only a big brain, but also very able hands. It’s not just the opposable thumbs – the entire structure of the hand is remarkable.

“The hand is one of the most important anatomical features that defines humans,” said study lead author Manuel Domínguez-Rodrigo, a paleoanthropologist at Complutense University of Madrid. “Our hand evolved to allow us a variety of grips and enough gripping power to allow us the widest range of manipulation observed in any primate. It is this manipulation capability that interacted with our brains to develop our intelligence.”

Many mammals and other animals have grasping appendages similar in form to a hand such as paws, claws, and talons, but these are not scientifically considered to be grasping hands. The only true grasping appears in primates, and apes are sometimes considered to have 4 hands, because they can also grasp with their ‘feet’.

If the bone is proportional in size to human bones, then the possessor of this bone would have been 5 feet 9 inches (1.75 meters) – a remarkable size when you compare it to Homo habilis, a hominin that measured only 3 feet high. The fact that human ancestors were so large comes as a surprise, but then again, there’s also a chance that the finger/body ratio wasn’t the same for them as it is for us.

Tiny but significant. Credit: Jason Heaton

Some scientists have often proposed that our hands evolved in conjunction with our use of tools, but recent discoveries suggest that the history of human hands is much more complicated. Modern humans are the only living higher primates to have straight finger bones, while hominin fingers were more curved, because they spent a great portion of time in the trees.

In a study published Tuesday in Nature Communications, researchers report the finding of an old fossil which also indicates straight fingers, and this just makes things more complicated. The straightness and other features of this new bone suggest adaptations for life on the ground rather than in the trees. This fills an important gap, but also raises more questions.

“Our discovery fills a gap — we found out that such a modern-looking hand is at least 1.85 million years old,” Domínguez-Rodrigo said.

Unfortunately, before we find more fossils, those questions will likely remained unanswered.

human hands ancestor

Early human ancestors used their hands much in the way as we do

After analyzing key hand bone fragments from fossil records, a team of anthropologists conclude that pre-homo  human ancestral species, such as Australopithecus africanus, used a hand posture very similar to that of modern humans. Considering fossil tools used for scrubbing off meat as old as 3.3 million years have been found, it may just be that our early ancestors weren’t all that different from good ol’ superior homo sapiens sapiens. Well, as far as hands go at least.

A handy ancestor

human hands ancestor

Like humans, chimps have opposable thumbs and opposable big toes which allow them to grip things with their feet. Yet, our close cousins don’t possess what scientists call a habile hand, since theirs haven’t been freed from walking requirements. As such, the evolution of the opposable or prehensile thumb is recognized by anthropologists as being linked with two key evolutionary transitions in hand use: a reduction in arboreal climbing and the manufacture and use of stone tools.

[RIDDLE] Which came first: the dexterous hand or the agile foot?

Matthew Skinner and Tracy Kivell of the Max Planck Institute for Evolutionary Anthropology and the University of Kent used new techniques to reveal how fossil species were using their hands by examining the internal spongey structure of bone called trabeculae. These bones quickly reshape during the lifetime to adapt to various stresses. So, for humans at least, you can tell whether a person is a carpenter, construction worker or a computer programmer, just by looking at the trabeculae.

The first metacarpals of a chimp, the fossil australopiths, and a human (top row). The bottom row constists of images from micro-computertomography-scans of the same specimens, showing a cross-section of the trabecular structure inside. © Tracy Kivell

The first metacarpals of a chimp, the fossil australopiths, and a human (top row). The bottom row constists of images from micro-computertomography-scans of the same specimens, showing a cross-section of the trabecular structure inside. © Tracy Kivell

[READ] Why early hominids started walking on two legs

A human forceful precision grip, grasping a Australopithecus africanus first metacarpal of the thumb. © Tracy Kivell & Matthew Skinner

A human forceful precision grip, grasping a Australopithecus africanus first metacarpal of the thumb.
© Tracy Kivell & Matthew Skinner

First, the researchers compared the trabeculae of humans and chimps. As expect, key differences were identified. The chimpanzee clearly can not adapt to human-like hand posture, lacking the ability for forceful precision gripping between thumb and fingers (e.g. like turning a key). Remarkably, a hominid ancestor called Australopithecus africanus, who lived some 3 to 2 million years ago, has a human-like trabecular bone pattern in the bones of the thumb and palm (the metacarpals) consistent with forceful opposition of the thumb and fingers typically adopted during tool use.

What makes this so important is that traditionally anthropologists believe Homo habilis, also known as “Handy Man,” was the first maker of stone tools. The models support previous archaeological evidence for stone tool use among australopiths, meaning the first tool use could be pushed back much earlier than previously thought – we just have to wait for evidence to surface, if any survived the test of time. What’s clear, though, is that our early ancestors used human-like hand postures frequently and earlier than currently estimated.

“This new evidence changes our understanding of the behaviour of our early ancestors and, in particular, suggests that in some aspects they were more similar to humans than we previously thought”, says Matthew Skinner of the Max Planck Institute for Evolutionary Anthropology and the University of Kent.

“There is growing evidence that the emergence of the genus Homo did not result from the emergence of entirely new behaviours but rather from the accentuation of traits already present in Australopithecus, including tool making and meat consumption”, says Jean-Jacques Hublin, director at the Max Planck Institute for Evolutionary Anthropology.

The original skull (without upper teeth and mandible) of a 2,1 million years old Australopithecus africanus specimen so-called “Mrs. Ples” discovered in South Africa. Image: Archaeodontosaurus/Wikipedia (CC BY-SA 4.0)

The original skull (without upper teeth and mandible) of a 2,1 million years old Australopithecus africanus specimen so-called “Mrs. Ples” discovered in South Africa. Image: Archaeodontosaurus/Wikipedia (CC BY-SA 4.0)

The results are published in Science.

(c) Bristol University, UK

Human-computer interface relays touch out of thin air

(c) Bristol University, UK

(c) Bristol University, UK

Using ultrasound radiation, researchers at University of Bristol (UK) have devised a computer interface that basically allows users to interact with a digital screen without touching it. Sure the Kinect or Leap Motion does this already, the catch is that this system also provides haptic (touch) feedback. So, whenever a user traces a motion in front of the system, not only does the system react, it also relays feedback to the users which senses it as touch. The device was unveiled this week at the ACM Symposium on User Interface Software and Technology in Scotland.

Dubbed, UltraHaptics the researchers claim the system’s main advantage is that it allows the user to “feel” what is on the screen.

“UltraHaptics uses the principle of acoustic radiation force where a phased array of ultrasonic transducers is used to exert forces on a target in mid-air,” Co-developer Tom Carter explained. “Haptic sensations are projected through a screen and directly onto the user’s hands.”

The system works by means of an ultrasound transducer array positioned beneath an acoustically transparent display, which doesn’t interfere with the haptic interaction. The multiple transducers join together and collectively emit very high frequency sound waves. When all of the sound waves meet at the same location at the same time, they create sensations on the skin. By creating multiple simultaneous feedback points, and giving them individual tactile properties, users can receive localized feedback associated to their actions. A LeapMotion device is used to relay hand movements.

Finally, the research team explored three new areas of interaction possibilities that UltraHaptics can provide: mid-air gestures, tactile information layers and visually restricted displays, and created an application for each.

A video demonstration of the UltraHaptic system can be viewed below.

Tom Carter, PhD student in the Department of Computer Science’s BIG research group, said: “Current systems with integrated interactive surfaces allow users to walk-up and use them with bare hands. Our goal was to integrate haptic feedback into these systems without sacrificing their simplicity and accessibility.

“To achieve this, we have designed a system with an ultrasound transducer array positioned beneath an acoustically transparent display. This arrangement allows the projection of focused ultrasound through the interactive surface and directly onto the users’ bare hands. By creating multiple simultaneous feedback points, and giving them individual tactile properties, users can receive localised feedback associated to their actions.”

UltraHaptics: Multi-Point Mid-Air Haptic Feedback for Touch Surfaces, Thomas Carter, Sue Ann Seah, Benjamin Long, Bruce Drinkwater, Sriram Subramanian, UIST 2013, 8-11 October, St Andrews, UK.