Pronunciation of ‘s’ sounds impacts perception of gender

A person’s style of speech — not just the pitch of his or her voice — may help determine whether the listener perceives the speaker to be male or female, according to a University of Colorado Boulder researcher who studied transgender people transitioning from female to male.

The way people pronounce their “s” sounds and the amount of resonance they use when speaking contributes to the perception of gender, according to Lal Zimman, whose findings are based on research he completed while earning his doctoral degree from CU-Boulder’s linguistics department.

Zimman presented his research on Saturday, January 5th at the 2013 annual meeting of the Linguistic Society of America in Boston.

“In the past, gender differences in the voice have been understood, primarily, as a biological difference,” Zimman said. “I really wanted to look at the potential for other factors, other than how testosterone lowers the voice, to affect how a person’s voice is perceived.”

As part of the process of transitioning from female to male, participants in Zimman’s study were treated with the hormone testosterone, which causes a number of physical changes including the lowering of a person’s voice. Zimman was interested in whether the style of a person’s speech had any impact on how low a voice needed to drop before it was perceived as male.

What he found was that a voice could have a higher pitch and still be perceived as male if the speaker pronounced “s” sounds in a lower frequency, which is achieved by moving the tongue farther away from the teeth.

“A high-frequency ‘s’ has long been stereotypically associated with women’s speech, as well as gay men’s speech, yet there is no biological correlate to this association,” said CU-Boulder linguistics and anthropology Associate Professor Kira Hall, who served as Zimman’s doctoral adviser. “The project illustrates the socio-biological complexity of pitch: the designation of a voice as more masculine or more feminine is importantly influenced by other ideologically charged speech traits that are socially, not biologically, driven.”

Vocal resonance also affected the perception of gender in Zimman’s study. A deeper resonance — which can be thought of as a voice that seems to be emanating from the chest instead of from the head — is the result of both biology and practice. Resonance is lower for people whose larynx is deeper in their throats, but people learn to manipulate the position of their larynx when they’re young, with male children pulling their larynxes down a little bit and female children pushing them up, Zimman said.

For his study, Zimman recorded the voices of 15 transgender men, all of whom live in the San Francisco Bay area. To determine the frequency of the “s” sounds each participant made, Zimman used software developed by fellow linguists. Then, to see how the “s” sounds affected perception, Zimman digitally manipulated the recording of each participant’s voice, sliding the pitch from higher to lower, and asked a group of 10 listeners to identify the gender of the speaker. Using the recordings, Zimman was able to pinpoint how low each individual’s voice had to drop before the majority of the group perceived the speaker to be male.

Botox may help stroke patients

Injecting botox into the arm muscles of stroke survivors, with severe spasticity, changes electrical activity in the brain and may assist with longer-term recovery, according to new research.

Researchers at NeuRA (Neuroscience Research Australia) monitored nerve activity in the arms and brains of stroke survivors before and after botulinum toxin (botox) injections in rigid and stiff muscles in the arm.

They found that botox indeed improved arm muscles, but also altered brain activity in the cortex – the brain region responsible for movement, memory, learning and thinking.

“Botulinum toxin is used to treat a range of muscular and neurological conditions and our data shows that this treatment results in electrical and functional changes within the brain itself”, says Dr William Huynh, lead author of the study and a research neurologist at NeuRA.

“This effect of botox on the brain may arise because the toxin travels to the central nervous system directly, or because muscles treated with botox are sending different signals back to the brain”.

“Either way, we found that botox treatment in affected muscles not only improves muscle disorders in stroke patients, but also normalises electrical activity in the brain, particularly in the half of the brain not damaged by stroke”.

“Restoring normal activity in the unaffected side of the brain is particularly important because we suspect that abnormal information sent from affected muscles to the brain may be disrupting patients’ long-term recovery”, Dr Huynh concluded.

This paper is published in the journal Muscle and Nerve.

Specific protein essential for healthy eyes

Researchers at the Hebrew University of Jerusalem, in collaboration with researchers at the Salk Institute in California,  have found for the first time that a specific protein is essential not only for maintaining a healthy retina in the eye, but also may have implications for understanding and possibly treating other conditions in the immune, reproductive, vascular and nervous systems, as well as in various cancers.

Their work, reported online in the journal Neuron, highlights the role of Protein S in the maintenance of a healthy retina through its involvement in the process of pruning photoreceptors, the light-sensitive neurons in the eye. (This process is also referred to as phagocytosis.) These photoreceptors keep growing and elongating from their inner end. In order to maintain a constant length, they must be pruned from their outer end by specialized cells called retinal pigment epithelial cells.

Without such pruning — which also clears away many free radicals and toxic by-products generated during visual biochemical reactions — photoreceptors would succumb to toxicity and degenerate, leading if unchecked to blindness. A receptor molecule called Mer is a key in photoreceptor pruning, and is therefore vital for retinal health. Mutations in the mouse, rat and human Mer genes cause retinal degeneration, which finally leads to blindness.

The Hebrew University study published in Neuron focuses on the molecules activating Mer in this pruning mechanism. Although two such molecules – Gas6 and Protein S — were identified previously, it was yet to be proven that they also play a role in a living organism. To show this, Dr. Tal Burstyn-Cohen of the Hebrew University Institute of Dental Sciences and colleagues at the Salk Institute in California found in their experiments on laboratory animals that both Gas6 and Protein S are needed to activate phagocytosis, or pruning, of retinal photoreceptors, and thus keep a healthy retina.

These findings could have practical implications, since Protein S also functions as a potent blood anticoagulant. People with Protein S deficiency are at risk for life threatening thrombosis (blood clots) and thromboembolism (a clot that breaks loose and is carried by the blood stream to plug another vessel).

These results further open new avenues of research into the role of Protein S in activating the receptors in other tissues where their function was shown to be important, such as in the immune, reproductive, vascular and nervous systems, as well as in various cancers where activation of receptors has been observed. For example, since Protein S is important for blood vessel formation, neutralizing Protein S in the blood vessels supplying blood to cancer growths could interfere with the cancerous blood supply.

(Image: Gemma Bou/Getty Images)

The pain puzzle: Uncovering how morphine increases pain in some people

For individuals with agonizing pain, it is a cruel blow when the gold-standard medication actually causes more pain. Adults and children whose pain gets worse when treated with morphine may be closer to a solution, based on research published in the January 6 on-line edition of Nature Neuroscience.

"Our research identifies a molecular pathway by which morphine can increase pain, and suggests potential new ways to make morphine effective for more patients," says senior author Dr. Yves De Koninck, Professor at Université Laval in Quebec City. The team included researchers from The Hospital for Sick Children (SickKids) in Toronto, the Institut universitaire en santé mentale de Québec, the US and Italy.

New pathway in pain management

The research not only identifies a target pathway to suppress morphine-induced pain but teases apart the pain hypersensitivity caused by morphine from tolerance to morphine, two phenomena previously considered to be caused by the same mechanisms.

"When morphine doesn’t reduce pain adequately the tendency is to increase the dosage. If a higher dosage produces pain relief, this is the classic picture of morphine tolerance, which is very well known. But sometimes increasing the morphine can, paradoxically, makes the pain worse," explains co-author Dr. Michael Salter. Dr. Salter is Senior Scientist and Head of Neurosciences & Mental Health at SickKids, Professor of Physiology at University of Toronto, and Canada Research Chair in Neuroplasticity and Pain.

"Pain experts have thought tolerance and hypersensitivity (or hyperalgesia) are simply different reflections of the same response," says Dr. De Koninck, "but we discovered that cellular and signalling processes for morphine tolerance are very different from those of morphine-induced pain."

Dr. Salter adds, “We identified specialized cells – known as microglia – in the spinal cord as the culprit behind morphine-induced pain hypersensitivity. When morphine acts on certain receptors in microglia, it triggers the cascade of events that ultimately increase, rather than decrease, activity of the pain-transmitting nerve cells.”

The researchers also identified the molecule responsible for this side effect of morphine. “It’s a protein called KCC2, which regulates the transport of chloride ions and the proper control of sensory signals to the brain,” explains Dr. De Koninck. “Morphine inhibits the activity of this protein, causing abnormal pain perception. By restoring normal KCC2 activity we could potentially prevent pain hypersensitivity.” Dr. De Koninck and researchers at Université Laval are testing new molecules capable of preserving KCC2 functions and thus preventing hyperalgesia.

The KCC2 pathway appears to apply to short-term as well as to long-term morphine administration, says Dr. De Koninck. “Thus, we have the foundation for new strategies to improve the treatment of post-operative as well as chronic pain.”

Dr. Salter adds, “Our discovery could have a major impact on individuals with various types of intractable pain, such as that associated with cancer or nerve damage, who have stopped morphine or other opiate medications because of pain hypersensitivity.”

Cost of pain

Pain has been labelled the silent health crisis, afflicting tens of millions of people worldwide. Pain has a profound negative effect on the quality of human life. Pain affects nearly all aspects of human existence, with untreated or under-treated pain being the most common cause of disability. The Canadian Pain Society estimates that chronic pain affects at least one in five Canadians and costs Canada $55-60 billion per year, including health care expenses and lost productivity.

"People with incapacitating pain may be left with no alternatives when our most powerful medications intensify their suffering," says Dr. De Koninck, who is also Director of Cellular and Molecular Neuroscience at Institut universitaire en santé mentale de Québec.

Dr. Salter adds, “Pain interferes with many aspects of an individual’s life. Too often, patients with chronic pain feel abandoned and stigmatized. Among the many burdens on individuals and their families, chronic pain is linked to increased risk of suicide. The burden of chronic pain affects children and teens as well as adults.” These risks affect individuals with many types of pain, ranging from migraine and carpel-tunnel syndrome to cancer, AIDS, diabetes, traumatic injuries, Parkinson’s disease and dozens of other conditions.

Humanity becomes technology

Humanity’s merge with its technology, which began shortly after the taming of fire, is still happening today. Many predict that the fine-tuning of our DNA-based biology through stem cell and genetic research will spark a powerful nanotech revolution that promises to redesign and rebuild our bodies and the environment, pushing the limits of today’s understanding of life and the world we live in.

Nanotech will change our physical world much the same way that computers have transformed our information world. Physical things such as cars and houses could follow the same path of computers, when Moore’s Law correctly predicted value-to-cost would increase by 50% every 18 months.

Existing products that are now expensive, such as photovoltaic solar cells, will become so cheap in the decades ahead, that it may one day be possible to surface roads with solar-collecting materials that would also gather energy to power cars, ending much of the world’s dependency on fossil fuels.

In addition, imagine machines that create clothing, medicine, food and most essentials, with only your voice needed to command the action. Today, such devices are not available, but by early 2030s, experts predict, a home nanofactory will provide most of your family’s needs at little or no cost.

Now bring on the most amazing impending revolution – human-level robots – with intelligence derived from us, but with redesigned bodies that exceed human capabilities. These powerful android creatures expected by 2030, will enable us to tap into their super-computer minds to increase our own intelligence. Constructed with molecular nanotech processes, they will be affordable for every family.

Finally, by mid-century, many people will complete the technology merge by replacing more of their biology with nanomaterials, creating a powerful body that can automatically repair itself when damaged. No more concerns over sickness, accidents, or unwanted death.

Evolution created humanity; humanity created technology, humanity will soon become technology. This is simply our next evolutionary step. Where this trip will take us may be beyond present day knowledge, but whatever the future holds, many people alive today can expect to experience all of its wonders.

Of course, not everyone may hold such a glowing vision of how life may unfold, but for one who has seen so many amazing changes over the past eighty two years, I think it difficult to imagine a negative outcome as we trek through what promises to be an incredible future.

Totally blind mice get sight back

Totally blind mice have had their sight restored by injections of light-sensing cells into the eye, UK researchers report. The team in Oxford said their studies closely resemble the treatments that would be needed in people with degenerative eye disease. Similar results have already been achieved with night-blind mice.

Experts said the field was advancing rapidly, but there were still questions about the quality of vision restored. Patients with retinitis pigmentosa gradually lose light-sensing cells from the retina and can become blind. The research team, at the University of Oxford, used mice with a complete lack of light-sensing photoreceptor cells in their retinas. The mice were unable to tell the difference between light and dark.

Reconstruction

They injected “precursor” cells which will develop into the building blocks of a retina once inside the eye. Two weeks after the injections a retina had formed, according to the findings presented in the Proceedings of the National Academy of Sciences journal. Prof Robert MacLaren said: “We have recreated the whole structure, basically it’s the first proof that you can take a completely blind mouse, put the cells in and reconstruct the entire light-sensitive layer.”

Previous studies have achieved similar results with mice that had a partially degenerated retina. Prof MacLaren said this was like “restoring a whole computer screen rather than repairing individual pixels”. The mice were tested to see if they fled being in a bright area, if their pupils constricted in response to light and had their brain scanned to see if visual information was being processed by the mind.

Vision

Prof Pete Coffee, from the Institute of Ophthalmology at University College London, said the findings were important as they looked at the “most clinically relevant and severe case” of blindness. “This is probably what you would need to do to restore sight in a patient that has lost their vision,” he said.

However, he said this and similar studies needed to show how good the recovered vision was as brain scans and tests of light sensitivity were not enough. He said: “Can they tell the difference between a nasty animal and something to eat?”

Prof Robin Ali published research in the journal Nature showing that transplanting cells could restore vision in night-blind mice and then showed the same technique worked in a range of mice with degenerated retinas. He said: “These papers demonstrate that it is possible to transplant photoreceptor cells into a range of mice even with a severe level of degeneration. “I think it’s great that another group is showing the utility of photoreceptor transplantation.”

Researchers are already trialling human embryonic stem cells, at Moorfields Eye Hospital, in patients with Stargardt’s disease. Early results suggest the technique is safe but reliable results will take several years.

Retinal chips or bionic eyes are also being trailed in patients with retinitis pigmentosa.

Decoding Dreams

“[I was] somewhere, in a place like a studio to make a TV program or something,” a groggy study participant recounted (in Japanese). “A male person ran with short steps from the left side to the right side. Then, he tumbled.” The participant had recently been awoken by Masako Tamaki, a postdoc in the lab of neuroscientist Yukiyasu Kamitani of the ATR Computational Neuroscience Laboratories in Kyoto, Japan. He was lying in a functional magnetic resonance imaging (fMRI) scanner, doing his best to recall what he had been dreaming about. “He stumbled over something, and stood up while laughing, and said something,” the participant continued. “He said something to persons on the left side.”

At first blush, the story doesn’t seem particularly informative. But the study subject saw a man, not a woman. And he was inside some sort of workplace. That fragmented information is enough for Kamitani and his team, who recorded dream appearances of 20 key objects, such as “male” or “room,” and used a machine-learning algorithm to correlate those concepts with the fMRI images to find patterns that could be used to predict what people were dreaming about without having to wake them. Such information could help inform the study of why people dream, an elusive question in neurobiology, Kamitani says. “Knowing what is represented during sleep would help to understand the function of dreaming.”

Analyzing more than 200 dream reports—some 30–45 hours of interviews with each of three participants—Kamitani and his colleagues built a “dream-trained decoder” based on fMRI imagery of the V1, V2, and V3 areas of the visual cortex. “We find some rule, or mapping, or pattern between what the person is seeing and what activity is happening in the brain,” Kamitani explains. And it worked, according to Kamitani, who presented the results at the Society for Neuroscience meeting in New Orleans in October 2012, predicting whether or not the 20 objects occurred in dreams with 75–80 percent accuracy.

But while Kamitani’s dream-decoding study is interesting, says neurobiologist David Kahn of Harvard Medical School, the algorithms used are quite primitive, only providing a handful of clues about the dream’s content. “We still have a long way to go before we can actually re-create the story that is the dream,” he says. “This is almost science fiction, because we’re way, way far from it … [but] this is an added tool.”

“Decoding is very primitive,” Kamitani agrees, “but I think there are a lot of potentials.” One way to get a more complete picture of the dream is to increase the complexity of the decoder, he notes. In this first study, for example, the researchers focused on nouns representing visual objects, but going forward, Kamitani says he hopes to include other concepts, like verbs. “By analyzing that aspect we may be able to add some action aspects in the dream.”

Furthermore, researchers might not have to fully interpret the dream themselves to benefit from the new decoder. Instead, the clues gleaned from the fMRI images could simply be used to jog participants’ memories. “We know that dreams—even the most vivid dreams we remember, [like] nightmares or lucid dreams—are really fragile memories,” says Antonio Zadra, an experimental psychologist at the University of Montreal. “Unless you wrote it down or told it to someone in the morning, usually even before lunch, that memory will start fading. And by night, you might just have the essence.”

Unfortunately, that failing memory was the only resource for researchers studying dreams. Now, with a little bit of supplemental information, they may be able to help participants recall dreams more precisely. “The subjective reports are never complete,” Kamitani says. “By giving the subject what we reconstructed, they may remember something more.”

At an even more basic level, the decoder could help scientists understand what’s happening in the brain during dreaming. “To create this whole virtual world out of nothing—with no visual input or auditory input—is quite fascinating and undoubtedly very complex,” Zadra says. “This research will certainly help us better understand what brain areas are doing what, to even allow for this to happen.”

In Kamitani’s study, for example, the researchers found that areas of higher-level visual processing, which respond to more abstract features, were more useful for interpreting dream content than lower-level processing areas. This makes sense, given that those lower areas of the visual cortex are more closely connected to the direct input from the retina. But, Kamitani notes, this could simply have to do with the way the study was designed. “We didn’t train the decoder with low-level visual features,” such as shape or contrast, he says. “We just used the semantic category information.”

Indeed, given the richness of the dreaming experience, such visual qualities may well be encoded during sleep. “Your brain creates a whole virtual world for you when you are dreaming, complete with characters, settings, interactions, dialogues,” says Zadra. “But you’re actually in your bed asleep; there is no visual input. So your brain is literally creating this virtual world from A to Z.”

Scientists explore the illusion of memory

A memory might seem like a permanent, precious essence carved deep into the circuits of the brain. But it is not. Instead, scientists are discovering that a memory changes every time you think about it.

"Every time you recall a memory, it becomes sensitive to disruption. Often that is used to incorporate new information into it." That’s the blunt assessment from one of the world’s leading experts on memory, Dr. Eric Kandel from Columbia University.

And that means our memories are not abstract snapshots stored forever in a bulging file in our mind, but rather, they’re a collection of brain cells — neurons that undergo chemical changes every time they’re engaged.

So when we think about something from the past, the memory is called up like a computer file, reviewed and revised in subtle ways, and then sent back to the brain’s archives, now modified slightly, updated, and changed.

As scientists increasingly understand the biological process of memory, they are also learning how to interrupt it, and that means they might one day be able to ease the pain of past trauma, or alter destructive habits and addictions, as though shaking an Etch A Sketch, erasing the scribbles on the mind, and starting fresh.

In his McGill University lab, researcher Karim Nader routinely erases the memory of his laboratory rats. But first he has to give them a memory and he does that by putting them in an isolation cubicle, playing a tone, and then delivering a small electrical shock to their feet.

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