Posts tagged psychology

Posts tagged psychology
About a dozen years ago, scientists discovered that a hormone called ghrelin enhances appetite. Dubbed the “hunger hormone,” ghrelin was quickly targeted by drug companies seeking treatments for obesity — none of which have yet panned out.

MIT neuroscientists have now discovered that ghrelin’s role goes far beyond controlling hunger. The researchers found that ghrelin released during chronic stress makes the brain more vulnerable to traumatic events, suggesting that it may predispose people to posttraumatic stress disorder (PTSD).
Drugs that reduce ghrelin levels, originally developed to try to combat obesity, could help protect people who are at high risk for PTSD, such as soldiers serving in war, says Ki Goosens, an assistant professor of brain and cognitive sciences at MIT, and senior author of a paper describing the findings in the Oct. 15 online edition of Molecular Psychiatry.
“Perhaps we could give people who are going to be deployed into an active combat zone a ghrelin vaccine before they go, so they will have a lower incidence of PTSD. That’s exciting because right now there’s nothing given to people to prevent PTSD,” says Goosens, who is also a member of MIT’s McGovern Institute for Brain Research.
Lead author of the paper is Retsina Meyer, a recent MIT PhD recipient. Other authors are McGovern postdoc Anthony Burgos-Robles, graduate student Elizabeth Liu, and McGovern research scientist Susana Correia.
Stress and fear
Stress is a useful response to dangerous situations because it provokes action to escape or fight back. However, when stress is chronic, it can produce anxiety, depression and other mental illnesses.
At MIT, Goosens discovered that one brain structure that is especially critical for generating fear, the amygdala, has a special response to chronic stress. The amygdala produces large amounts of growth hormone during stress, a change that seems not to occur in other brain regions.
In the new paper, Goosens and her colleagues found that the release of the growth hormone in the amygdala is controlled by ghrelin, which is produced primarily in the stomach and travels throughout the body, including the brain.
Ghrelin levels are elevated by chronic stress. In humans, this might be produced by factors such as unemployment, bullying, or loss of a family member. Ghrelin stimulates the secretion of growth hormone from the brain; the effects of growth hormone from the pituitary gland in organs such as the liver and bones have been extensively studied. However, the role of growth hormone in the brain, particularly the amygdala, is not well known.
The researchers found that when rats were given either a drug to stimulate the ghrelin receptor or gene therapy to overexpress growth hormone over a prolonged period, they became much more susceptible to fear than normal rats. Fear was measured by training all of the rats to fear an innocuous, novel tone. While all rats learned to fear the tone, the rats with prolonged increased activity of the ghrelin receptor or overexpression of growth hormone were the most fearful, assessed by how long they froze after hearing the tone. Blocking the cell receptors that interact with ghrelin or growth hormone reduced fear to normal levels in chronically stressed rats.
When rats were exposed to chronic stress over a prolonged period, their circulating ghrelin and amygdalar growth hormone levels also went up, and fearful memories were encoded more strongly. This is similar to what the researchers believe happens in people who suffer from PTSD.
“When you have people with a history of stress who encounter a traumatic event, they are more likely to develop PTSD because that history of stress has altered something about their biology. They have an excessively strong memory of the traumatic event, and that is one of the things that drives their PTSD symptoms,” Goosens says.
New drugs, new targets
Over the last century, scientists have described the hypothalamic-pituitary-adrenal (HPA) axis, which produces adrenaline, cortisol (corticosterone in rats), and other hormones that stimulate “fight or flight” behavior. Since then, stress research has focused almost exclusively on the HPA axis.
After discovering ghrelin’s role in stress, the MIT researchers suspected that ghrelin was also linked to the HPA axis. However, they were surprised to find that when the rats’ adrenal glands — the source of corticosterone, adrenaline, and noradrenaline — were removed, the animals still became overly fearful when chronically stressed. The authors also showed that repeated ghrelin-receptor stimulation did not trigger release of HPA hormones, and that blockade of the ghrelin receptor did not blunt release of HPA stress hormones. Therefore, the ghrelin-initiated stress pathway appears to act independently of the HPA axis. “That’s important because it gives us a whole new target for stress therapies,” Goosens says.
Pharmaceutical companies have developed at least a dozen possible drug compounds that interfere with ghrelin. Many of these drugs have been found safe for humans, but have not been shown to help people lose weight. The researchers believe these drugs could offer a way to vaccinate people entering stressful situations, or even to treat people who already suffer from PTSD, because ghrelin levels remain high long after the chronic stress ends.
PTSD affects about 7.7 million American adults, including soldiers and victims of crimes, accidents, or natural disasters. About 40 to 50 percent of patients recover within five years, Meyer says, but the rest never get better.
The researchers hypothesize that the persistent elevation of ghrelin following trauma exposure could be one of the factors that maintain PTSD. “So, could you immediately reverse PTSD? Maybe not, but maybe the ghrelin could get damped down and these people could go through cognitive behavioral therapy, and over time, maybe we can reverse it,” Meyer says.
Working with researchers at Massachusetts General Hospital, Goosens’ lab is now planning to study ghrelin levels in human patients suffering from anxiety and fear disorders. They are also planning a clinical trial of a drug that blocks ghrelin to see if it can prevent relapse of depression.
(Source: web.mit.edu)
Chimpanzees communicate with robots
Chimpanzees are willing to socialise with robots, new research reveals. It is the first time that robots have been used to study behaviour in primates other than humans.
The study, by researchers at the University of Portsmouth, shows that chimps respond to even basic movements made by a robot, demonstrating that chimps want to communicate and interact with other ‘creatures’ on a social level. The researchers believe that these basic forms of communication in chimpanzees help to promote greater social bonding and lead to more complex forms of social interaction.
The research, published in Animal Cognition a few days ago, outlines how chimps responded to a human-like robot about the size of a doll. The chimps reacted to small movements made by the robot by inviting play, offering it toys and in one case even laughing at it. They also responded to being imitated by the robot.
The chimps did not appear to be put off by the primitive nature of the gestures but responded in the same way they might to humans or other chimps.
Lead researcher, Dr Marina Davila-Ross, is from the University’s Centre for Comparative and Evolutionary Psychology. She said that the advantage of using a robot in the study was that the chimps could be observed in a controlled but interactive setting while a human researcher was able to examine the chimps’ behaviour without needing to participate. This allowed the researchers to analyse simplest forms of ’social’ interactions.
She said: “It was especially fascinating to see that the chimps recognised when they were being imitated by the robot because imitation helps to promote their social bonding. They showed less active interest when they saw the robot imitate a human.
“Some of the chimps gave the robot toys and other objects and demonstrated an active interest in communicating. This kind of behaviour helps to promote social interactions and friendships. But there were notable differences in how the chimps behaved. Some chimps, for instance, seemed not interested in interacting with the robot and turned away as soon as they saw it.
“In our other studies we have found that humans will also react to robots in ways which suggest a willingness to communicate, even though they know the robots are not real. It’s a demonstration of the basic human desire to communicate and it appears that chimpanzees share this readiness to communicate with others.”
The interactive robot was approximately 45 centimetres high and its head and limbs could move independently while chimpanzee sounds (such as chimpanzee laughter) were sent via a small loudspeaker in its chest area, which was covered by a dress. The chimps first observed a person interacting with the robot which was then turned around to face the chimp while the human researcher looked away to avoid any further communication.
Almost all of the 16 chimpanzees observed showed a level of active communication with the robot, such as gestures and expressions.
Dr Davila-Ross said that the research paves the way for further study using robots to interact with primates and discover more about their social behaviour in a controlled setting, such as how they make friends.
Researchers find that ‘peanut butter’ test can help diagnose Alzheimer’s disease
A dollop of peanut butter and a ruler can be used to confirm a diagnosis of early stage Alzheimer’s disease, University of Florida Health researchers have found.
Jennifer Stamps, a graduate student in the UF McKnight Brain Institute Center for Smell and Taste, and her colleagues reported the findings of a small pilot study in the Journal of the Neurological Sciences.
Stamps came up with the idea of using peanut butter to test for smell sensitivity while she was working with Dr. Kenneth Heilman, the James E. Rooks distinguished professor of neurology and health psychology in the UF College of Medicine’s department of neurology.
She noticed while shadowing in Heilman’s clinic that patients were not tested for their sense of smell. The ability to smell is associated with the first cranial nerve and is often one of the first things to be affected in cognitive decline. Stamps also had been working in the laboratory of Linda Bartoshuk, the William P. Bushnell presidentially endowed professor in the College of Dentistry’s department of community dentistry and behavioral sciences and director of human research in the Center for Smell and Taste.
“Dr. Heilman said, ‘If you can come up with something quick and inexpensive, we can do it,’” Stamps said.
She thought of peanut butter because, she said, it is a “pure odorant” that is only detected by the olfactory nerve and is easy to access.
In the study, patients who were coming to the clinic for testing also sat down with a clinician, 14 grams of peanut butter — which equals about one tablespoon — and a metric ruler. The patient closed his or her eyes and mouth and blocked one nostril. The clinician opened the peanut butter container and held the ruler next to the open nostril while the patient breathed normally. The clinician then moved the peanut butter up the ruler one centimeter at a time during the patient’s exhale until the person could detect an odor. The distance was recorded and the procedure repeated on the other nostril after a 90-second delay.
The clinicians running the test did not know the patients’ diagnoses, which were not usually confirmed until weeks after the initial clinical testing.
The scientists found that patients in the early stages of Alzheimer’s disease had a dramatic difference in detecting odor between the left and right nostril — the left nostril was impaired and did not detect the smell until it was an average of 10 centimeters closer to the nose than the right nostril had made the detection in patients with Alzheimer’s disease. This was not the case in patients with other kinds of dementia; instead, these patients had either no differences in odor detection between nostrils or the right nostril was worse at detecting odor than the left one.
Of the 24 patients tested who had mild cognitive impairment, which sometimes signals Alzheimer’s disease and sometimes turns out to be something else, about 10 patients showed a left nostril impairment and 14 patients did not. The researchers said more studies must be conducted to fully understand the implications.
“At the moment, we can use this test to confirm diagnosis,” Stamps said. “But we plan to study patients with mild cognitive impairment to see if this test might be used to predict which patients are going to get Alzheimer’s disease.”
Stamps and Heilman point out that this test could be used by clinics that don’t have access to the personnel or equipment to run other, more elaborate tests required for a specific diagnosis, which can lead to targeted treatment. At UF Health, the peanut butter test will be one more tool to add to a full suite of clinical tests for neurological function in patients with memory disorders.
One of the first places in the brain to degenerate in people with Alzheimer’s disease is the front part of the temporal lobe that evolved from the smell system, and this portion of the brain is involved in forming new memories.
“We see people with all kinds of memory disorders,” Heilman said. Many tests to confirm a diagnosis of Alzheimer’s disease or other dementias can be time-consuming, costly or invasive. “This can become an important part of the evaluation process.”
A study at Texas Christian University in Fort Worth has found that the attractiveness of others can have an impact on how much we lie or misrepresent and to the extent that we believe those lies/misrepresentations.
For example, Harry gets a call from a political polling organization and is asked for his opinion of the Patient Protection and Affordable Care Act. He gives it the lowest possible rating. A few weeks later, Harry meets an attractive woman named Sally online. During their conversation, Sally mentions that she answered the same question by the same polling organization and expressed high approval of Obamacare. She then asks “What approval rating did you give Obamacare when they asked you?”
This question poses a dilemma for Harry. Should he tell the truth or should he shade the truth? To the extent that Harry finds Sally very attractive and is motivated to create a positive impression, he might shade the truth about his past behavior by claiming to have expressed at least moderate approval of Obamacare. What, if any, effect would this misrepresentation have on Harry’s memory for how he actually answered on the day he was contacted by the polling organization?
“What we know is that people will embellish or distort facts when telling stories, which causes them to oftentimes remember the lies more so than the truth,” said Charles Lord, professor of psychology at Texas Christian University in Fort Worth. “Research has also showed us that people tell others what they want to hear. In this case, Harry will lie to impress Sally, and he is also more likely to fool himself into believing the lie.”
Researchers asked single individuals if they agreed or disagreed with instituting “comprehensive mandatory exams” for graduating seniors using a 1-10 scale. A total of 44 individuals did not want to institute mandatory exams. Those respondents were then led to believe they would be meeting a member of the opposite sex who wanted to institute mandatory exams by scoring those a nine on the survey. They also were shown a photo of this person and asked to report on a 1-7 scale if they found their partner “physically attractive and wanted to get along with and make a good impression on this partner.”
Participants were then asked to complete a profile to be sent to their partner before an in-person meeting answering the same question about “comprehensive mandatory exams.” Researchers found there was a correlation between the attractiveness of the partner and those warming to the idea of “comprehensive mandatory exams.”
Researchers then retested students with some of the same questions they had taken two weeks earlier by asking respondents to remember what they had said in the initial survey.
“Participants with relatively attractive potential partners remembered giving more positive initial survey responses than participants with relatively unattractive potential partners,” said Lord.
Researchers then tested 117 additional undergraduate students letting them see profile pictures and foreknowledge of how those students responded. They were told they would be partnered with these individuals later in the course. Findings showed that people with perceived “attractive partners” aligned their views more closely with the partner than those with unattractive partners.
“In both experiments we found that knowing the other person’s positive evaluation in advance led participants to misrepresent their own previous evaluations, and this misrepresentation, in turn, altered memories for participants’ own actual past actions,” said Lord.
These findings appear in the forthcoming edition of the Journal of Social Cognition.
(Source: newswise.com)
Finding that the opioid system can act to ease social pain, not just physical pain, may aid understanding of depression and social anxiety

A brain image showing in orange/red one area of the brain where the natural painkiller (opioid) system was highly active in research volunteers who are experiencing social rejection. This region, called the amygdala, was one of several where the U-M team recorded the first images of this system responding to social pain, not just physical pain. Studying this response, and the variation between people, could aid understanding of depression and anxiety. Credited to UofM Health.
“Sticks and stones may break my bones, but words will never hurt me,” goes the playground rhyme that’s supposed to help children endure taunts from classmates. But a new study suggests that there’s more going on inside our brains when someone snubs us – and that the brain may have its own way of easing social pain.
The findings, recently published in Molecular Psychiatry by a University of Michigan Medical School team, show that the brain’s natural painkiller system responds to social rejection – not just physical injury.
What’s more, people who score high on a personality trait called resilience – the ability to adjust to environmental change – had the highest amount of natural painkiller activation.
(Source: uofmhealth.org)
Egoism and narcissism appear to be on the rise in our society, while empathy is on the decline. And yet, the ability to put ourselves in other people’s shoes is extremely important for our coexistence. A research team headed by Tania Singer from the Max Planck Institute for Human Cognitive and Brain Sciences has discovered that our own feelings can distort our capacity for empathy. This emotionally driven egocentricity is recognised and corrected by the brain. When, however, the right supramarginal gyrus doesn’t function properly or when we have to make particularly quick decisions, our empathy is severely limited.
When assessing the world around us and our fellow humans, we use ourselves as a yardstick and tend to project our own emotional state onto others. While cognition research has already studied this phenomenon in detail, nothing is known about how it works on an emotional level. It was assumed that our own emotional state can distort our understanding of other people’s emotions, in particular if these are completely different to our own. But this emotional egocentricity had not been measured before now.
This is precisely what the Max Planck researchers have accomplished in a complex marathon of experiments and tests. They also discovered the area of the brain responsible for this function, which helps us to distinguish our own emotional state from that of other people. The area in question is the supramarginal gyrus, a convolution of the cerebral cortex which is approximately located at the junction of the parietal, temporal and frontal lobe. “This was unexpected, as we had the temporo-parietal junction in our sights. This is located more towards the front of the brain,” explains Claus Lamm, one of the publication’s authors.
On the empathy trail with toy slime and synthetic fur
Using a perception experiment, the researchers began by showing that our own feelings actually do influence our capacity for empathy, and that this egocentricity can also be measured. The participants, who worked in teams of two, were exposed to either pleasant or unpleasant simultaneous visual and tactile stimuli.
While participant 1, for example, could see a picture of maggots and feel slime with her hand, participant 2 saw a picture of a puppy and could feel soft, fleecy fur on her skin. “It was important to combine the two stimuli. Without the tactile stimulus, the participants would only have evaluated the situation ‘with their heads’ and their feelings would have been excluded,” explains Claus Lamm. The participants could also see the stimulus to which their team partners were exposed at the same time.
The two participants were then asked to evaluate either their own emotions or those of their partners. As long as both participants were exposed to the same type of positive or negative stimuli, they found it easy to assess their partner’s emotions. The participant who was confronted with a stinkbug could easily imagine how unpleasant the sight and feeling of a spider must be for her partner.
Differences only arose during the test runs in which one partner was confronted with pleasant stimuli and the other with unpleasant ones. Their capacity for empathy suddenly plummeted. The participants’ own emotions distorted their assessment of the other person’s feelings. The participants who were feeling good themselves assessed their partners’ negative experiences as less severe than they actually were. In contrast, those who had just had an unpleasant experience assessed their partners’ good experiences less positively.
Particularly quick decisions cause a decline in empathy
The researchers pinpointed the area of the brain responsible for this phenomenon with the help of functional magnetic resonance imaging, generally referred to as a brain scanning. The right supramarginal gyrus ensures that we can decouple our perception of ourselves from that of others. When the neurons in this part of the brain were disrupted in the course of this task, the participants found it difficult not to project their own feelings onto others. The participants’ assessments were also less accurate when they were forced to make particularly quick decisions.
Up to now, the social neuroscience models have assumed that we mainly draw on our own emotions as a reference for empathy. This only works, however, if we are in a neutral state or the same state as our counterpart – otherwise, the brain must counteract and correct.
Studying the social side of carnivores
The part of the brain that makes humans and primates social creatures may play a similar role in carnivores, according to a growing body of research by a Michigan State University neuroscientist.
In studying spotted hyenas, lions and, most recently, the raccoon family, Sharleen Sakai has found a correlation between the size of the animals’ frontal cortex and their social nature.
In her latest study, Sakai examined the digitally recreated brains of three species in the Procyonid family – the raccoon, the coatimundi and the kinkajou – and found the coatimundi had the largest frontal cortex. The frontal cortex is thought to regulate social interaction, and the coatimundi is by far the most social of the three animals, often living in bands of 20 or more.
The study, funded by the National Science Foundation, is published in the research journal Brain, Behavior and Evolution.
“Most neuroscience research that looks at how brains evolve has focused primarily on primates, so nobody really knows what the frontal cortex in a carnivore does,” said Sakai, professor of psychology. “These findings suggest the frontal cortex is processing social information in carnivores perhaps similar to what we’ve seen in monkeys and humans.”
Sakai did the most recent study in her neuroscience lab with Bradley Arsznov, a former MSU doctoral student who’s now an assistant professor of psychology at Minnesota State University. Sakai is one of myriad MSU faculty members who help make the university’s brain research portfolio one of the most diverse in the nation.
Her latest study was based on the findings from 45 adult Procyonid skulls acquired from university museum collections (17 coatimundis, 14 raccoons and 14 kinkajous). The researchers used computed tomography, or CT scans, and sophisticated software to digitally “fill in” the areas where the brains would have been.
When they analyzed into the findings, they discovered the female coatimundi had the largest anterior cerebrum volume consisting mainly of the frontal cortex, which regulates social activity in primates. This makes sense, Sakai said, since the female coatimundi is highly social while the male coatimundi, once grown, typically lives on its own or with another male. Also known as the Brazilian aardvark, the coatimundi – or coati – is native to Central and South America.
Raccoons, the most solitary of the three animals, had the smallest frontal cortex. However, raccoons had the largest posterior cerebrum, which contains the sensory area related to forepaw sensation and dexterity – and the raccoon’s forepaws are extremely dexterous and highly sensitive.
The rainforest-dwelling kinkajou had the largest cerebellum and brain stem, areas that regulate motor coordination. This skill is crucial for animals like the kinkajou that live in trees.
Brain size variations in this small family of carnivores appear to be related to differences in behavior including social interaction, Sakai said.
Brain anatomy and language in young children
Language ability is usually located in the left side of the brain. Researchers studying brain development in young children who were acquiring language expected to see increasing levels of myelin, a nerve fiber insulator, on the left side. They didn’t: The larger myelin structure was already there. Their study underscores the importance of environment in language development.
Researchers from Brown University and King’s College London have gained surprising new insights into how brain anatomy influences language acquisition in young children.
Their study, published in the Journal of Neuroscience, found that the explosion of language acquisition that typically occurs in children between 2 and 4 years old is not reflected in substantial changes in brain asymmetry. Structures that support language ability tend to be localized on the left side of the brain. For that reason, the researchers expected to see more myelin — the fatty material that insulates nerve fibers and helps electrical signals zip around the brain — developing on the left side in children entering the critical period of language acquisition. But that is not what the research showed.
“What we actually saw was that the asymmetry of myelin was there right from the beginning, even in the youngest children in the study, around the age of 1,” said the study’s lead author, Jonathan O’Muircheartaigh, the Sir Henry Wellcome Postdoctoral Fellow at King’s College London. “Rather than increasing, those asymmetries remained pretty constant over time.”
That finding, the researchers say, underscores the importance of environment during this critical period for language.
O’Muircheartaigh is currently working in Brown University’s Advanced Baby Imaging Lab. The lab uses a specialized MRI technique to look at the formation of myelin in babies and toddlers. Babies are born with little myelin, but its growth accelerates rapidly in the first few years of life.
The researchers imaged the brains of 108 children between ages 1 and 6, looking for myelin growth in and around areas of the brain known to support language.
While asymmetry in myelin remained constant over time, the relationship between specific asymmetries and language ability did change, the study found. To investigate that relationship, the researchers compared the brain scans to a battery of language tests given to each child in the study. The comparison showed that asymmetries in different parts of the brain appear to predict language ability at different ages.
“Regions of the brain that weren’t important to successful language in toddlers became more important in older children, about the time they start school,” O’Muircheartaigh said. “As language becomes more complex and children become more proficient, it seems as if they use different regions of the brain to support it.”
Interestingly, the association between asymmetry and language was generally weakest during the critical language period.
“We found that between the ages of 2 and 4, myelin asymmetry doesn’t predict language very well,” O’Muircheartaigh said. “So if it’s not a child’s brain anatomy predicting their language skills, it suggests their environment might be more influential.”
The researchers hope this study will provide a helpful baseline for future research aimed at pinpointing brain structures that might predict developmental disorders.
“Disorders like autism, dyslexia, and ADHD all have specific deficits in language ability,” O’Muircheartaigh said. “Before we do studies looking at abnormalities we need to know how typical children develop. That’s what this study is about.”
“This work is important, as it is the first to investigate the relationship between brain structure and language across early childhood and demonstrate how this relationship changes with age,” said Sean Deoni, assistant professor of engineering, who oversees the Advanced Baby Imaging Lab. “The study highlights the advantage of collaborative work, combining expertise in pediatric imaging at Brown and neuropsychology from the King’s College London Institute of Psychiatry, making this work possible.”
In a breakthrough for understanding brain evolution, neuroscientists have shown that differences between primate brains - from the tiny marmoset to human – can be largely explained as consequences of the same genetic program.

In research published in the Journal of Neuroscience, Professor Marcello Rosa and his team at Monash University’s School of Biomedical Sciences and colleagues at Universidade Federal do Rio de Janeiro, in Brazil, used computer modelling to demonstrate that the substantial enlargement of some areas of the human brain, vital to advanced cognition, reflected a consistent pattern that is seen across primate species of all sizes.
This finding suggests how the neural circuits responsible for traits that we consider uniquely human – such as the ability to plan, make complex decisions and speak – could have emerged simply as a natural consequence of the evolution of larger brains.
“We have known for a long time that certain areas of the human brain are much larger than one would expect based on how monkey brains are organised,” Professor Rosa said.
“What no one had realised is that this selective enlargement is part of a trend that has been present since the dawn of primates.”
Using publicly available brain maps, MRI imaging data and modelling software, the neuroscientists compared the sizes of different brain areasin humans and three monkey species: marmosets, capuchins and macaques. They found that two regions, the lateral prefrontal cortex and the temporal parietal junction, expand disproportionally to the rest of the brain.
The prefrontal cortex is related to long term planning, personality expression, decision-making, and behaviour modification. The temporal parietal junction is related to self-awareness and self-other distinction.
Lead author Tristan Chaplin, from the Department of Physiology will commence his PhD next year. He said the findings showed that those areas of the brain grew disproportionately in a predictable way.
“We found that the larger the brain is, the larger these areas get,” Tristan said.
“When you go from a small to big monkey - the marmoset to macaque - the prefrontal cortex and temporal parietal junction get larger relative to the rest of the cortex, and we see the same thing again when you compare macaques to humans.”
“This trend argues against the view that specific human mutations gave us these larger areas and advanced cognition and behaviour, but are a consequence of what happens in development when you grow a larger brain,” Tristan said.
Professor Rosa said the pattern held for primate species that evolved completely separately.
"If you compare the capuchin of South America and the macaque of Asia, their brains are almost identical, although they developed on opposite sides of the world. They both reflect the genetic plan of how a primate brain grows," Professor Rosa said.
This is the first computational comparative study conducted across several primate species. Tristan now hopes, in collaboration with zoos, to check if our closest primate relatives, the chimpanzees and gorillas, also have brain areas organised as his theory predicts.
(Source: monash.edu.au)
Subtle body cues allow people to identify others with surprising accuracy when faces are difficult to differentiate. This skill may help researchers improve person-recognition software and expand their understanding of how humans recognize each other.
A study published in Psychological Science by researchers at The University of Texas at Dallas demonstrates that humans rely on non-facial cues, such as body shape and build, to identify people in challenging viewing conditions, such as poor lighting.
“Psychologists and computer scientists have concentrated almost exclusively on the role of the face in person recognition,” explains lead researcher Allyson Rice. “Our results show that the body can also provide important and sometimes sufficient identity information for person recognition.”
During several experiments, researchers asked college-age participants to look at images of two people side-by-side and identify whether the images showed the same person. Some pairs looked similar despite showing different people, while other image pairs showed the same person with a different appearance. The researchers used computer face recognition systems to find pairs of pictures in which facial characteristics were difficult to use for identity.
Overall, participants accurately discerned whether the images showed the same person when they were provided complete images that showed both the face and body. Participants were just as accurate in identifying people in the image pairs when the faces were blocked out and only the bodies were shown. But, similarly to the computer-based face recognition system, participants had trouble identifying images of the subjects’ faces without their bodies.

Image: Above are pairs of photographs that face-recognition software failed to identify correctly. The top two photos are of the same person, while the bottom two photos are of different people
When asked, participants thought they were using primarily facial features to identify the subjects. To unravel the paradox, the researchers used eye-tracking equipment to determine where participants were actually looking. They found participants spent more time looking at the body whenever the face did not provide enough information to identify the subjects.
“People’s recognition strategies were inaccessible to their conscious awareness,” Rice said. “This provides a cautionary tale in ascribing credibility to people’s subjective reports of how they came to an identity decision.”
Dr. Alice O’Toole, Aage and Margareta Møller Professor in the School of Behavioral and Brain Sciences, has worked on facial recognition for over 15 years and supervised the project.
“Given the widespread use of face recognition systems in security settings, it is important for these systems to make use of all potentially helpful information,” O’Toole said. “Our work shows that the body can be surprisingly useful for identification, especially when the face fails to provide the necessary identity information.”
(Source: utdallas.edu)