Smell of rosemary ‘may improve memory’

System Provides Clear Brain Scans of Awake, Unrestrained Mice

Setting a mouse free to roam might alarm most people, but not so for nuclear imaging researchers from the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, Oak Ridge National Laboratory, Johns Hopkins Medical School and the University of Maryland who have developed a new imaging system for mouse brain studies.

Scientists use dynamic imaging of mice to follow changes in brain chemistry caused by the progression of disease or the application of a drug as an effective research tool for developing better ways to diagnose disease and formulate better treatments. In most nuclear imaging studies, laboratory mice are typically drugged or bound in place so that their brains can be studied. However, the results of such research can be tainted by subjecting the mice to such chemical or physical restraints, complicating studies of Alzheimer’s, dementia and Parkinson’s disease.

But for their nuclear medicine imaging studies, the researchers from Jefferson Lab, Oak Ridge, Johns Hopkins and Maryland used a new system they developed to acquire functional images of the brains of conscious, unrestrained and un-anesthetized mice. The so-called AwakeSPECT system was then used to document for the first time the effects of anesthesia on the action of a dopamine transporter imaging compound in the mouse brain. Such dopamine transporter imaging compounds are used for Alzheimer’s, dementia and Parkinson’s disease studies.

SPECT is Single-Photon Emission Computed Tomography. In this technique, a radionuclide is injected, where it collects in specific areas of the brain by function. The radionuclide emits gamma rays (single photons) that are collected by a detector in separate scans from many different angles. The scans are combined in an algorithm to produce a three-dimensional image.

"The AwakeSPECT system does regular SPECT imaging of mice. SPECT is a nuclear medicine imaging technique that’s used in humans for various types of diagnostic studies. It’s also used in animal studies to facilitate the development and understanding of disease physiology," says Jefferson Lab’s Drew Weisenberger, who led the multi-institutional collaboration and directed the SPECT system development effort.

Weisenberger says the AwakeSPECT system uses two Jefferson Lab custom-built gamma cameras to image the radionuclide, as well as a system that processes the data to produce the three-dimensional images. An infrared camera system developed at Oak Ridge National Laboratory tracks movement of the mouse. Finally, a commercially available CT system provides additional anatomical information.

Researchers at Johns Hopkins Medical School, led by Martin Pomper, conducted the first mouse imaging studies with the new system. To prepare a mouse for imaging with AwakeSPECT, it is first tagged with three markers that are glued to its head for the infrared system to track. Once the radionuclide is injected, the mouse can then be imaged as it rests in a homey, burrow-like, clear tube. The beauty of the system is that it doesn’t require that the mouse (or potentially people, at a later stage) remain motionless. Two patents have been awarded to Jefferson Lab for the innovative technology associated with this system.

"We developed this system that, while acquiring SPECT images, uses infrared cameras that track the location and pose of the head. We use that information to then computationally remove motion artifacts from our SPECT imaging," he says.

In this recent study published online in The Journal of Nuclear Medicine, the researchers showed that AwakeSPECT can obtain detailed, functional images of the brain of a conscious mouse, as the mouse moves around freely in an enclosure.

Researchers also imaged the action of a drug often used to image dopamine transport in the brain, ¹²³I-ioflupane, in awake and anesthetized mice. They found that the drug was absorbed less than half as well in awake mice, showing that the use of anesthetic could potentially confound drug uptake studies.

"We’ve shown the technology works. Now, you just have to make it a tool that more people will readily use" Weisenberger says.

Weisenberger says the next step is to improve the AwakeSPECT imager by upgrading the infrared tracking system, using newer technology for the SPECT imager, and by making the system more intuitive for animal researchers to operate.

How ‘free will’ is implemented in the brain and is it possible to intervene in the process?

Researchers have been able to identify the precise moment when a network of nerve cells (neurons) in the brain creates the signal to perform an action, before a person is even aware of deciding to take that action. Now they are building on this work to make initial attempts to interfere with consciously made decisions by decoding the pattern of brain activity in real time before an action is taken.

Professor Gabriel Kreiman will tell the British Neuroscience Association Festival of Neuroscience (BNA2013) today (Tuesday): “This could be useful to help elucidate the mechanistic basis by which neuronal circuits orchestrate ‘free’ will.”

Normally it is difficult to research the activity of neurons in the brain because it involves implanting electrodes – an invasive procedure that would not be ethical to do simply for scientific curiosity alone. However, Prof Kreiman, who is an associate professor at the Harvard Medical School, Boston, USA, together with neurosurgeon Itzhak Fried from University of California at Los Angeles (UCLA), had a rare opportunity to record the activity of over 1,000 neurons in two areas of the brain, the frontal and temporal lobes, when patients with epilepsy had had electrodes implanted to try to identify the source of their seizures.

“These patients have epilepsy that does not respond to drug treatment; Itzhak Fried implanted their brains with very thin electrodes (microwires) of about 40 micrometres in diameter in order to localise the focus of a seizure onset for a potential surgical procedure to alleviate the seizures. The microwires capture the extracellular electrical activity of neurons. Patients stay in the hospital for about a week. During this time, we have a unique opportunity to interrogate the activity of neurons and neural ensembles in the human brain at high spatial and temporal resolution,” explains Prof Kreiman.

The researchers asked the patients to move their index finger to click a computer mouse and to report when they made that decision. “Based on the activity of small groups of neurons, we could predict this decision several hundreds of milliseconds and, in some cases, seconds before the action. In a variant of the main experiment, the patients were allowed to choose whether to use their left hand or right hand and we showed that we could also predict this decision.”

The researchers found that an increasing number of neurons in two specific brain regions started to become active before the person was aware of their decision to move their finger. The two regions were the supplementary motor area, which is thought to be the area for preparing to perform motor actions, and the anterior cingulate cortex, which has a number of roles including the signalling processes associated with reward.

Prof Kreiman believes that these results provide initial steps to elucidate the mechanism for the emergence of conscious will in humans. “The activity of multiple neurons in extremely simple neural circuits precedes volition – in this case the decision to make a simple movement – until a threshold is crossed and the action is taken,” he will say.

Knowing when this threshold will be reached could enable researchers to see whether it is possible to interfere and maybe change the decision before any action is taken. “We are now making initial attempts to interfere with volition by decoding the neural responses in real time and asking whether there is a ‘point of no return’ in the hierarchical chain of command from unconscious decisions to volition to action,” says Prof Kreiman.

How these findings fit into the concept of “free will” is more complicated. “The concept of free will has been debated for millennia. Ultimately, current scientific understanding strongly suggests that ‘will’ has to be orchestrated by neurons in our brains (as opposed to magic or religious beliefs or other notions). We have provided initial steps to try to disentangle which neurons are involved, to show where and how ‘will’ or ‘volition’ could be implemented in the brain.

“Our work does not say that life is predetermined, that we can predict the future and that we can, for instance, determine what you are going to eat for lunch two weeks from now, or who you are going to marry.

“We are saying that volition (like other aspects of consciousness) is a brain phenomenon that is instantiated by physical hardware, i.e. neurons.  We are making claims about volition for very simple tasks, such as moving an index finger or choosing which hand to use, over scales of hundreds of milliseconds to seconds. Nothing more. Nothing less.

“Ultimately, our actions depend on multiple variables, several of which are external (for instance, it rains, hence, I will take my umbrella) and cannot be decoded or predicted from neurons. However, our volitional decision of whether to take the red umbrella or the blue one today – ultimately perhaps the real core of free will – is dictated by neurons,” Prof Kreiman will conclude.

Legal high Benzo Fury may be dangerous due to stimulant and hallucinogenic effects

The ‘legal high’ known as Benzo Fury may have stimulant as well as hallucinogenic effects according to new research presented at the British Neuroscience Association Festival of Neuroscience today (Tuesday 9 April 2013).

In a poster presentation at the meeting, Dr Jolanta Opacka-Juffry and Dr Colin Davidson reported that one of the main ingredients of Benzo Fury (also known as 5-APB) acts on brain tissue like both a stimulant and a hallucinogen – a combination of properties that is often found in illegal drugs and which can make them dangerous to users. The researchers believe this information should be disseminated to let potential users know the possible dangers of the drug.

Dr Opacka-Juffry, who is a principal lecturer in neuroscience and director of the health sciences research centre at the University of Roehampton, and Dr Davidson, senior lecturer in neuropharmacology and expert in drugs of addiction at St George’s, University of London, studied the effect of 5-APB samples from the brains of rats. In particular, they looked at the effect it had on serotonin receptors, which are affected by hallucinogenic drugs, and on a protein called the dopamine transporter (DAT), which pumps a neurotransmitter, dopamine, back in to nerve cells, terminating its activity, and which is involved in addiction. They compared the effects of 5-APB with those caused by cocaine and amphetamine.

“We have found that 5-APB behaves a little like amphetamine – that is, like a stimulant with addictive potential – and a bit like a hallucinogen, acting via serotonin receptors. This kind of mixed properties can be found in some illegal ‘designer’ drugs,” the presenting author, Dr Opacka-Juffry said.

“This finding is significant because it demonstrates that some ‘legal highs’ may have addictive properties, which are unlikely to be well-known amongst the users of these drugs. In addition, its effects on the serotonin receptors – known as 5-HT2A receptors – would suggest that it may lead to high blood pressure by causing constriction of the blood vessels, which would make the drug more dangerous. It is possible that the reason these drugs are so popular is because they are seen as safer than their illegal counterparts. It is important to challenge these assumptions.”

The researchers also found that 5-APB caused “reverse transport of dopamine”.

Dr Davidson said: “In theory, drugs which cause reverse transport could cause damage to the dopamine nerve cells. Other drugs such as amphetamines can also cause reverse transport, where dopamine is displaced from the nerve rather than mopped up by the dopamine transporter.”

Dr Opacka-Juffry said: “It is in the combination of these stimulant and hallucinogenic properties that the greatest danger lies. Pure hallucinogens are not addictive as such because they do not cause an increase in dopamine release, unlike amphetamine or cocaine. They are attractive to many people who enjoy the ‘mind altering’ properties of hallucinogens. But Benzo Fury with its mixed properties is a trap as its repetitive use for the hallucinogenic effects could lead to dependence, which the user may not expect.”

Further work needs to be carried out to find out more. “Rat data are quite informative as the brain addiction pathway is similar in rodents and humans. Long-term effects should be tested in rodents to investigate the potential toxic effects on the nervous system and the cardiovascular system, in addition to its liability for abuse due to addiction. We also need to collate data from human users. Taken together we can determine how dangerous this drug is,” she said.

Benzo Fury is currently one of the most popular legal highs in the UK and is also sold in the USA. It appears to be fairly easy to buy via the internet, at music festivals and clubs, and its street price is around £10 a pill or £25 for three. “However, tragedies such as the death of 19-year-old Alex Heriot at a music festival in June 2012 after taking Benzo Fury demonstrate the importance of making as much information available as possible about the potential adverse effects of these ‘highs’ as quickly as possible,” said Dr Opacka-Juffry.

Drs Opacka-Juffry and Davidson report that the approach they used to study Benzo Fury could be applied to other drugs as well, so that as new legal high drugs emerge, they can be tested quickly against the “gold standard” drugs such as cocaine and amphetamines to establish their relative danger.

Dr Davidson said: ”Over the last few years 40 or more new legal highs have appeared each year. Given the speed with which legal highs are developed and reach the market, it is important to be able to respond quickly to assess their potential dangers, and disseminate this information accordingly.”

Researchers create next-generation Alzheimer’s disease model

A new genetically engineered lab rat that has the full array of brain changes associated with Alzheimer’s disease supports the idea that increases in a molecule called beta-amyloid in the brain causes the disease, according to a study, published in the Journal of Neuroscience. The study was supported by the National Institutes of Health.

"We believe the rats will be an excellent, stringent pre-clinical model for testing experimental Alzheimer’s disease therapeutics,” said Terrence Town, Ph.D., the study’s senior author and a professor in the Department of Physiology & Biophysics in the Zilkha Neurogenetic Institute at the University of Southern California Keck School of Medicine, Los Angeles.

Alzheimer’s is an age-related brain disorder that gradually destroys a person’s memory, thinking, and the ability to carry out even the simplest tasks. Affecting at least 5.1 million Americans, the disease is the most common form of dementia in the United States. Pathological hallmarks of Alzheimer’s brains include abnormal levels of beta-amyloid protein that form amyloid plaques; tau proteins that clump together inside neurons and form neurofibrillary tangles; and neuron loss.  

Additionally, glial cells—which normally support, protect, or nourish nerve cells—are overactivated in Alzheimer’s.

Plaque-forming beta-amyloid molecules are derived from a larger protein called amyloid precursor protein (APP). One hypothesis states that increases in beta-amyloid initiate brain degeneration. Genetic studies on familial forms of Alzheimer’s support the hypothesis by linking the disease to mutations in APP, and to presenilin 1, a protein thought to be involved in the production beta-amyloid.

Researchers often use rodents to study diseases. However, previous studies on transgenic mice and rats that have the APP and presenilin 1 mutations only partially reproduce the problems caused by Alzheimer’s. The animals have memory problems and many plaques but none of the other hallmarks, especially neurofibrillary tangles and neuron loss.

To address this issue, Dr. Town and his colleagues decided to work with a certain strain of rats.

“We focused on Fischer 344 rats because their brains develop many of the age-related features seen in humans,” said Dr. Town, who conducted the study while working as a professor of Biomedical Sciences at Cedars-Sinai Medical Center and David Geffen School of Medicine at the University of California, Los Angeles.

The rats were engineered to have the mutant APP and presenilin 1 genes, which are known to play a role in the rare, early-onset form of Alzheimer’s. Behavioral studies showed that the rats developed memory and learning problems with age. As predicted, the presence of beta-amyloid in the brains of the rats increased with age. However, unlike previous rodent studies, the rats also developed neurofibrillary tangles.

“This new rat model more closely represents the brain changes that take place in humans with Alzheimer’s, including tau pathology and extensive neuronal cell death,” said Roderick Corriveau, Ph.D., a program director at NIH’s National Institute of Neurological Disorders and Stroke. “The model will help advance our understanding of the various disease pathways involved in Alzheimer’s onset and progression and assist us in testing promising interventions.”

The researchers performed a variety of experiments confirming the presence of neurofibrillary tangles in brain regions most affected by Alzheimer’s such as the hippocampus and the cingulate cortex, which are involved in learning and memory. Further experiments showed that about 30 percent of neurons in these regions died with age, the largest amount of cell death seen in an Alzheimer’s rodent model, and that some glial cells acquired shapes reminiscent of the activated glia found in patients.

“Our results suggest that beta-amyloid can drive Alzheimer’s in a clear and progressive way,” said Dr. Town.

Activation of glia occurred earlier than amyloid plaque formation, which suggests Dr. Town and his colleagues identified an early degenerative event and new treatment target that scientists studying other rodent models may have missed.

The findings support a prime research objective identified during the May 2012, NIH-supported Alzheimer’s Disease Research Summit 2012: Path to Treatment and Prevention, an international gathering of Alzheimer’s researchers and advocates. Improved animal models were cited as key to advancing understanding of this complex disease.

"To fully benefit from this exciting new work, there is a critical need to share the animal model with researchers dedicated to finding ways to delay, prevent or treat Alzheimer’s disease’’ said Neil Buckholtz, Ph.D., of the National Institute on Aging, which leads the NIH effort in Alzheimer’s research. “Accordingly, Dr. Town and his colleagues are working towards making their new rat model easily accessible to the research community.”

Remarkable Success In Patients With Major Depression

For the first time, physicians from the Bonn University Hospital have stimulated patients’ medial forebrain bundles.

Researchers from the Bonn University Hospital implanted pacemaker electrodes into the medial forebrain bundle in the brains of patients suffering from major depression with amazing results: In six out of seven patients, symptoms improved both considerably and rapidly. The method of Deep Brain Stimulation had already been tested on various structures within the brain, but with clearly lesser effect. The results of this new study have now been published in the renowned international journal “Biological Psychiatry.”

After months of deep sadness, a first smile appears on a patient’s face. For many years, she had suffered from major depression and tried to end her life several times. She had spent the past years mostly in a passive state on her couch; even watching TV was too much effort for her. Now this young woman has found her joie de vivre again, enjoys laughing and traveling. She and an additional six patients with treatment resistant depression participated in a study involving a novel method for addressing major depression at the Bonn University Hospital.

Considerable amelioration of depression within days

Prof. Dr. Volker Arnd Coenen, neurosurgeon at the Department of Neurosurgery (Klinik und Poliklinik für Neurochirurgie), implanted electrodes into the medial forebrain bundles in the brains of subjects suffering from major depression with the electrodes being connected to a brain pacemaker. The nerve cells were then stimulated by means of a weak electrical current, a method called Deep Brain Stimulation. In a matter of days, in six out of seven patients, symptoms such as anxiety, despondence, listlessness and joylessness had improved considerably. “Such sensational success both in terms of the strength of the effects, as well as the speed of the response has so far not been achieved with any other method,” says Prof. Dr. Thomas E. Schläpfer from the Bonn University Hospital Department of Psychiatry und Psychotherapy (Bonner Uniklinik für Psychiatrie und Psychotherapie).

Central part of the reward circuit

The medial forebrain bundle is a bundle of nerve fibers running from the deep-seated limbic system to the prefrontal cortex. In a certain place, the bundle is particularly narrow because the individual nerve fibers lie close together. “This is exactly the location in which we can have maximum effect using a minimum of current,” explains Prof. Coenen, who is now the new head of the Freiburg University Hospital’s Department of Stereotactic and Functional Neurosurgery (Abteilung Stereotaktische und Funktionelle Neurochirurgie am Universitätsklinikum Freiburg). The medial forebrain bundle is a central part of a euphoria circuit belonging to the brain’s reward system. What kind of effect stimulation exactly has on nerve cells is not yet known. But it obviously changes metabolic activity in the different brain centers.

Success clearly increased over that of earlier studies

The researchers have already shown in several studies that deep brain stimulation shows an amazing and–given the severity of the symptoms– unexpected degree of amelioration of symptoms in major depression. In those studies, however, the physicians had not implanted the electrodes into the medial forebrain bundle but instead into the nucleus accumbens, another part of the brain’s reward system. This had resulted in clear and sustainable improvements in about 50 percent of subjects. “But in this new study, our results were even much better,” says Prof. Schläpfer. A clear improvement in complaints was found in 85 percent of patients, instead of the earlier 50 percent. In addition, stimulation was performed with lower current levels, and the effects showed within a few days, instead of after weeks.

Method’s long-term success proven

“Obviously, we have now come closer to a critical structure within the brain that is responsible for major depression,” says the psychiatrist from the Bonn University Hospital. Another cause for optimism among the group of physicians is that, since the study’s completion, an eighth patient has also been treated successfully. The patients have been observed for a period of up to 18 month after the intervention. Prof. Schläpfer reports, “The anti-depressive effect of deep brain stimulation within the medial forebrain bundle has not decreased during this period.” This clearly indicates that the effects are not temporary. This method gives those who suffer from major depression reason to hope. However, it will take quite a bit of time for the new procedure to become part of standard therapy.

Producing new neurones under all circumstances: a challenge that is just a mouse away …

Improving neurone production in elderly persons presenting with a decline in cognition is a major challenge facing an ageing society and the emergence of neuro-degenerative conditions such as Alzheimer’s disease. INSERM and CEA researchers recently showed that the pharmacological blocking of the TGFβ molecule improves the production of new neurones in the mouse model. These results incentivise the development of targeted therapies enabling improved neurone production to alleviate cognitive decline in the elderly and reduce the cerebral lesions caused by radiotherapy.

The research is published in the journal EMBO Molecular Medicine.

New neurones are formed regularly in the adult brain in order to guarantee that all our cognitive capacities are maintained. This neurogenesis may be adversely affected in various situations and especially:

- in the course of ageing,
- after radiotherapy treatment of a brain tumour. (The irradiation of certain areas of the brain is, in fact, a central adjunctive therapy for brain tumours in adults and children).

According to certain studies, the reduction in our “stock” of neurones contributes to an irreversible decline in cognition. In the mouse, for example, researchers reported that exposing the brain to radiation in the order of 15 Gy is accompanied by disruption to the olfactive memory and a reduction in neurogenesis. The same happens in ageing in which a reduction in neurogenesis is associated with a loss of certain cognitive faculties. In patients receiving radiotherapy due to the removal of a brain tumour, the same phenomena can be observed.

Researchers are studying how to preserve the “neurone stock”. To do this, they have tried to discover which factors are responsible for the decline in neurogenesis.

Contrary to what might have been believed, their initial observations show that neither heavy doses of radiation nor ageing are responsible for the complete disappearance of the neural stem cells capable of producing neurones (and thus the origin of neurogenesis). Those that survive remain localised in a certain small area of the brain (the sub-ventricular zone (SVZ)). They nevertheless appear not to be capable of working correctly.

Additional experiments have made it possible to establish that in both situations, irradiation and ageing, high levels of the cytokine TGFβ cause the stem cells to become dormant, increasing their susceptibility to apoptosis (PCD) and reducing the number of new neurones.

“Our study concluded that although neurogenesis reduced in ageing and after a high dose of radiation, many stem cells survive for several months, retaining their ‘stem’ characteristics”, explains Marc-Andre Mouthon, one of the main authors of the research, that was conducted in conjunction with José Piñeda and François Boussin.

The second part of the project demonstrated that pharmacological blocking of TGFβ restores the production of new neurones in irradiated or ageing mice.

For the researchers, these results will encourage the development of targeted therapies to block TGFβ in order to reduce the impact of brain lesions caused by radiotherapy and improving the production of neurones in the elderly presenting with a cognitive decline.

Reframing Stress: Stage Fright Can Be Your Friend

Fear of public speaking tops death and spiders as the nation’s number one phobia. But new research shows that learning to rethink the way we view our shaky hands, pounding heart, and sweaty palms can help people perform better both mentally and physically.

Before a stressful speaking task, simply encouraging people to reframe the meaning of these signs of stress as natural and helpful was a surprisingly effective way of handling stage fright, found the study to be published online April 8 in Clinical Psychological Science.

"The problem is that we think all stress is bad," explains Jeremy Jamieson, the lead author on the study and an assistant professor of psychology at the University of Rochester. "We see headlines about ‘Killer Stress’ and talk about being ‘stressed out.’" Before speaking in public, people often interpret stress sensations, like butterflies in the stomach, as a warning that something bad is about to happen, he says.

"But those feelings just mean that our body is preparing to address a demanding situation," explains Jamieson. "The body is marshaling resources, pumping more blood to our major muscle groups and delivering more oxygen to our brains." Our body’s reaction to social stress is the same flight or fight response we produce when confronting physical danger. These physiological responses help us perform, whether we’re facing a bear in the forest or a critical audience.

For many people, especially those suffering from social anxiety disorder, the natural uneasiness experienced before giving a speech can quickly tip over into panic. “If we think we can’t cope with stress, we will experience threat. When threatened, the body enacts changes to concentrate blood in the core and restricts flow to the arms, legs, and brain,” he explains. So, “cold feet” is a real physiological response to threat, not just a colorful expression.

"Lots of current advice for anxious people focuses on learning to ‘relax,’—you know, deep, even breathing and similar tips," says Jamieson. Such calming techniques, write the authors, may be helpful in situations that do not require peak performance. But when gearing up for a high-stakes exam, a job interview, or, yes, a speaking engagement, reframing how we think about stress may be a better strategy.

Then how can people reap the benefits of being stressed without being overwhelmed by dread? To answer that question, Jamieson and co-authors Matthew Nock, of Harvard University and Wendy Berry Mendes of the University of California in San Francisco, turned to the Trier Social Stress Test. Developed in 1993 by Clemens Kirschbaum and colleagues, this experiment relies on fear of public speaking and has become one of the most reliable laboratory methods for eliciting threat responses.

In the study, 69 adults were asked to give a five-minute talk about their strengths and weaknesses with only three minutes to prepare. Roughly half of the participants had a history of social anxiety and all participants were randomly assigned to two groups. The first group was presented information about the advantages of the body’s stress response and encouraged to “reinterpret your bodily signals during the upcoming public speaking task as beneficial.” That group also was asked to read summaries of three psychology studies that showed the benefits of stress. The second group received no information about reframing stress.

Participants delivered their speech to two judges. On purpose, the judges provided negative nonverbal feedback throughout the entire five-minute presentations, shaking their heads in disapproval, tapping on their clipboards, and staring stone-faced ahead. If study subjects ran out of things to say, the judges insisted that they continue speaking for the full five minutes. Following the speech, participants were asked to count backwards for five minutes in steps of seven beginning with the number 996. The evaluators again provided negative feedback throughout and insisted that participants start over if they made any mistakes.

Confronted with scowling judges, participants who received no stress preparation experienced a threat response, as captured by cardiovascular measures. But the group that was prepped about the benefits of stress weathered the trial better. That group reported feeling that they had more resources to cope with the public speaking task and, perhaps more tellingly, their physiological responses confirmed those perceptions. The prepped group pumped more blood through the body per minute compared to the group that did not receive instruction.

Surprisingly, this study also found that individuals who suffer from social anxiety disorder actually experienced no greater increase in physiological arousal while under scrutiny than their non-anxious counterparts, despite reporting more intense feelings of apprehension. This disconnect, argue the authors, supports the theory that our experience of acute or short-term stress is shaped by how we interpret physical cues. “We construct our own emotions,” says Jamieson.

Rare primate’s vocal lip-smacks share features of human speech

The vocal lip-smacks that geladas use in friendly encounters have surprising similarities to human speech, according to a study reported in the Cell Press journal Current Biology on April 8th. The geladas, which live only in the remote mountains of Ethiopia, are the only nonhuman primate known to communicate with such a speech-like, undulating rhythm. Calls of other monkeys and apes are typically one or two syllables and lack those rapid fluctuations in pitch and volume.

This new evidence lends support to the idea that lip-smacking, a behavior that many primates show during amiable interactions, could have been an evolutionary step toward human speech.

"Our finding provides support for the lip-smacking origins of speech because it shows that this evolutionary pathway is at least plausible," said Thore Bergman of the University of Michigan in Ann Arbor. "It demonstrates that nonhuman primates can vocalize while lip-smacking to produce speech-like sounds."

Bergman first began to wonder about the geladas’ sounds when he began his fieldwork in 2006. “I would find myself frequently looking over my shoulder to see who was talking to me, but it was just the geladas,” he recalled. “It was unnerving to have primate vocalizations sound so much like human voices.”

That was something that he had never experienced in the company of other primates. Then Bergman came across a paper in Current Biology last year proposing vocalization while lip-smacking as a possible first step to human speech, and something clicked.

Bergman has now analyzed recordings of the geladas’ vocalizations, known as “wobbles,” to find a rhythm that closely matches human speech. In other words, because they vocalize while lip-smacking, the pattern of sound produced is structurally similar to human speech.

In both lip-smacking and speech, the rhythm corresponds to the opening and closing of parts of the mouth. What’s more, Bergman said, lip-smacking might serve the same purpose as language in many basic human interactions—think of how friends bond through small talk.

"Language is not just a great tool for exchanging information; it has a social function," Bergman said. "Many verbal exchanges appear to serve a function similar to lip-smacking."