Biological Psychology Links

by Paul Marks How do you give a robot a sharper sense of smell? By using genetically modified frog cells, according to Shoji Takeuchi, a bioengineer at the University of Tokyo in Japan. Today's electronic noses are not up to the job, he says. Although e-noses have been around for a while – and are used to sniff out rotten food in production lines – they lack accuracy. That's because e-noses use quartz rods designed to vibrate at a different frequency when they bind to a target substance. But this is not a foolproof system, as subtly different substances with similar molecular weights may bind to the rod, producing a false positive. Instead, Takeuchi believes there is nothing quite as good as biology for distinguishing between different biomolecules, such as disease markers in our breath. So he and his team have developed a living smell sensor. First, immature eggs, or oocytes, from the African clawed frog Xenopus laevis were genetically modified to express the proteins known to act as smell receptors. He chose X. laevis cells as they are widely studied and their protein expression mechanism is well understood. © Copyright Reed Business Information Ltd.

By Susan Milius In a long-running war between bats and moths, at least one bat has gotten the upper wing. Western barbastelle bats in Europe typically ping out their echolocation calls softly enough to locate a moth for dinner before the moth hears them coming, says Holger Goerlitz of the University of Bristol in England. It’s the first documented case of a bat species outwitting its prey by quiet stealth, he and his colleagues say online in a Current Biology paper released August 19. The battle between bats and moths has become a classic system for studying the evolution of predators and their prey. In searching for moths, barbastelles echolocate at about the 94 decibel level, roughly the equivalent of a busy highway, Goerlitz reports. This bat version of whispering is 10 to 100 times lower in amplitude than other aerial-hunting bats’ echolocation calls. Those rank more in the range of jet engines and the vuvuzelas blaring at the latest World Cup, Goerlitz says. People can’t hear frequencies high enough to detect any of this bat racket — “quite lucky for us,” Goerlitz says. To measure the loudness of the barbastelle calls, researchers needed to know how far away from a microphone a flying bat was when it pinged. So they set up a microphone array where bats swooped through at night. The slight differences in times that the calls took to reach different microphones let researchers figure out the bat’s position for each of more than 100 calls. © Society for Science & the Public 2000 - 2010

By Nathan Seppa The prevalence of hearing loss in teenagers rose by nearly one-third in recent years compared with the rate in the 1980s and 1990s, a new study shows. The findings come as a surprise to the study’s authors, who had expected overall hearing to improve thanks to publicity about the risks of exposure to loud music and the advent of childhood vaccines against meningitis and pneumonia that can prevent many ear infections. But in the August 18 Journal of the American Medical Association, the scientists report that the portion of U.S. adolescents aged 12 to 19 with any hearing loss rose from 14.9 percent during the 1988 to 1995 period to 19.5 percent in 2005 and 2006. Researchers based the analysis on information gathered from nearly 3,000 kids in the earlier time frame and more than 1,700 in the later sampling. The findings suggest that as many as 6.5 million teens in the United States now have some hearing loss. The surveys used largely similar questionnaires and standard hearing tests in which “any hearing loss” was defined as a loss of 15 decibels in at least one ear. That is, a person was determined to have some hearing loss if a tone had to be increased by 15 dB or more beyond the standard detection level to be heard at least half the time. Hearing loss of 25 dB or greater is less common, particularly in children. But it also rose, from 3.5 to 5.3 percent, between the study time frames. The rate of hearing loss increased in high — but not low — frequencies, the researchers found. © Society for Science & the Public 2000 - 2010

by Bijal Trivedi CLAIRE CHESKIN used to live in a murky world of grey, her damaged eyes only seeing large objects if they were right next to her. She could detect the outlines of people but not their expressions, and could just about make out the silhouettes of buildings, but no details. Looking into the distance? Forget it. Nowadays things are looking distinctly brighter for Cheskin. Using a device called vOICe, which translates visual images into "soundscapes", she has trained her brain to "see through her ears". When travelling, the device helps her identify points of interest; at home she uses it to find things she has put down, like coffee cups. "I've sailed across the English Channel and across the North Sea, sometimes using the vOICe to spot landmarks," she says. "The lights on the land were faint but the vOICe could pick them up." As if the signposting of objects wasn't impressive and useful enough, some long-term users of the device like Cheskin eventually report complete images somewhat akin to normal sight, thanks to a long-term rewiring of their brains. Sometimes these changes are so profound that it alters their perceptions even when they aren't using the device. As such, the vOICe (the "OIC" standing for "Oh, I See") is now proving invaluable as a research tool, providing insights into the brain's mind-boggling capacity for adaptation. The idea of hijacking another sense to replace lost vision has a long history. One of the first "sensory substitution" devices was developed in 1969 by neuroscientist Paul Bach-y-Rita. He rigged up a television camera to a dentist's chair, on which was a 20-by-20 array of stimulators that translated images into tactile signals by vibrating against the participant's back. Despite the crudeness of the set-up, it allowed blind participants to detect the presence of horizontal, vertical and diagonal lines, while skilled users could even associate the physical sensations with faces and common objects. © Copyright Reed Business Information Ltd.

By Jason Palmer Research has shown that bacteria - among the simplest life forms on Earth - have a sense of smell. Scientists from Newcastle University in the UK have demonstrated that a bacterium commonly found in soil can sniff and react to ammonia in the air. It was previously thought that this "olfaction" was limited to more complex forms of life known as eukaryotes. The finding, published in Biotechnology Journal, means that bacteria have four of the five senses that humans enjoy. The discovery also has implications in the understanding and control of biofilms - the chemical coatings that bacteria can form on, for example, medical implants. Bacteria have already demonstrated the ability to react to light, in analogy to sight, and to change the genes that they express when confronted with certain materials, in analogy to touch. However, there is a distinction between an organism reacting to a chemical that it encounters directly (in analogy to the sense of taste) and a reaction to a chemical that is floating around in the air, says Reindert Nijland, lead author of the study. "The difference is both in the mechanism that does the sensing, as well as in the compounds that are sensed," Dr Nijland, now at University Medical Centre Utrecht in the Netherlands, told BBC News. "The compounds detected by olfactory organs are generally much more volatile than things you can taste like 'sweet' or 'salt', and therefore can provide information about things that can be much further away; you can smell a barbecue from a few blocks away whereas you have to physically touch and eat the steak to be able to actually taste it." (C)BBC

By Bruce Bower At scientific meetings, psycho-biologist Colwyn Trevarthen often plays a video of a 5-month-old Swedish girl giving her mother a musical surprise. Blind from birth, the girl reaches for a bottle and laughs appreciatively as her mother launches into a familiar song about feeding blueberries to a bear. As in baby songs everywhere, Trevarthen says, each line of the Swedish tune runs about four seconds and each stanza lasts about 20. In a flash, the girl raises her left arm — an arm she has never seen — and begins conducting her mother’s performance. The baby, named Maria, moves her arm just before many of the song’s lines begin, leading her mother by about one-third of a second. In some cases, Maria synchronizes her hand movements with the rise and fall of her mother’s voice. Mom’s face glows in response to Maria’s playful directions. “Babies are born with a musical readiness that includes a basic sense of timing and rhythm,” declares Trevarthen, of the University of Edinburgh. Scientists have been finding that these chubby-cheeked cherubs heed a musical sense that moves them and grooves them long before they utter a word. Within a day or two after birth, babies recognize the first beat in a sound sequence; neural signs of surprise appear when that initial “downbeat” goes missing. Classical music lights up specific hearing areas in newborns’ right brains. Even more intriguingly, babies enter the world crying in melodic patterns that the little ones have heard in their mothers’ conversations for at least two months while in the womb (SN: 12/5/09, p. 14). © Society for Science & the Public 2000 - 2010

By Susan Gaidos Anyone who has felt the sting of tears while listening to a bugler play “Taps,” swooned to a love song or cringed with irritation as a neighbor cranked the heavy metal knows that music can exert a powerful emotive effect. And you don’t need a neuroscientist to tell you that manipulating a melody’s pace, tone and intensity can stir the emotions. Composers of symphonies, pop tunes, movie sound tracks and TV ads all know how to tune an audience’s mood along a dial ranging from sad and glum to cheerful and chipper. But neuroscientists might have something to say about how music orchestrates such profound emotional effects on the brain. And understanding the how may offer a hint as to why music affects humans so powerfully. Over the past decade or so, studies have shown that music stimulates numerous regions of the brain all at once, including those responsible for emotion, memory, motor control, timing and language. While the lyrics of a song activate language centers, such as Broca’s area, other parts of the brain may connect the tune to a long-ago association — a first kiss or a road trip down the coast, perhaps. “It’s like the brain is on fire when you’re listening to music,” says Istvan Molnar-Szakacs, a neuroscientist at the University of California, Los Angeles. “In terms of brain imaging, studies have shown listening to music lights up, or activates, more of the brain than any other stimulus we know.” © Society for Science & the Public 2000 - 2010

By Rachel Ehrenberg Not so long ago, Mozart mania swept the nation. A small study found that students who listened to 10 minutes of a Mozart sonata performed better on a paper-folding task than their peers, and suddenly a flourishing industry sprouted. Mozart’s music sang from CDs and videos marketed for children, babies and moms-to-be. The craze reached a crescendo when Georgia’s governor Zell Miller included $105,000 in his state budget to send every child born in a Georgia hospital home with a classical music tape or CD. “No one questions that listening to music at a very early age affects the spatial, temporal reasoning that underlies math and engineering and even chess,” Miller said. Actually, a lot of researchers questioned the link between listening to music and smarts. In the original study, the “Mozart effect” was minor and lasted only minutes. Follow-up studies found the effect specific neither to the composer nor to music. Students listening to Mozart were just more stimulated than those listening to a relaxation tape or silence. And while arousal can improve learning, research suggests, the effects can be fleeting and aren’t limited to music. Assessments of the original report now tend to be dirges: In the May-June issue of Intelligence, researchers from the University of Vienna published a paper titled “Mozart effect–Shmozart effect.” “It’s a short-lived effect and it spawned a huge industry of baby Einstein, baby Mozart CDs, all sorts of stuff,” says Aniruddh Patel of the Neurosciences Institute in San Diego. “But the science behind it is pretty thin.” © Society for Science & the Public 2000 - 2010

By Susan Milius WILLIAMSBURG, Va. — Putting a female lemur on birth control turns her normally informative scents to nonsense, researchers report. Doses of Depo-Provera, a common contraceptive for people, shift the odor secretions of female lemurs so dramatically that their scents no longer give clear cues to kinship, identity and genetic quality, says study coauthor Christine Drea of Duke University in Durham, N.C. A female lemur whose hormones are disrupted by contraceptives may have real trouble attracting a compatible mate, Drea said July 26 at the annual meeting of the Animal Behavior Society. As for people, men and women might not think they’re influenced by each others’ scents, but “Oh, we are!” said behavioral biologist Susan Jenks of the Sage Colleges in Troy, N.Y., after Drea’s presentation. If women react to the hormones the way lemurs do, “maybe you don’t want to be on contraceptives when you’re picking your mate.” Also, said behavioral ecologist Jill Mateo of the University of Chicago, “For any zoo that is chemically contracepting animals, this could have big implications.” Drea and her colleagues have identified more than 300 compounds in the scent secretions of female lemurs. “There is a rich communication system,” she said. Glands on the forelimbs, tail and other parts of the body secrete chemical cues that the lemurs rub onto branches or other community bulletin boards, where neighbors sniff out the news. © Society for Science & the Public 2000 - 2010

by Dolly J. Krishnaswamy Seven months ago, a 51-year-old woman known only to the public as patient LI1 suffered a severe stroke and lost her ability to communicate with the outside world. She couldn't even blink her eyes. But now, thanks to a new technology, the woman can write long, emotional e-mails to her loved ones just by sniffing. Like many quadriplegics, patient LI1's stroke damaged a region high up on her spinal column, paralyzing her from the neck down. But LI1's injury was so extensive that she also lost the ability to speak. Such patients are referred to as "locked-in" because they can't communicate with the outside world, even though their brain functions normally. Some can blink to answer simple yes or no questions or even string words together by picking out letters as someone recites them (as in the case of Jean-Dominique Bauby, author of The Diving Bell and the Butterfly). But this isn't an option for Patient LI1. So neurobiologist Noam Sobel of the Weizmann Institute of Science in Rehovot, Israel, turned to sniffing. He and colleagues had been studying the human sense of smell and had developed a device, which looks like the oxygen tubes patients wear in the hospital, that releases an odor when a subject sniffs forcefully. Sobel's team soon realized that the device could be configured to respond to various types of sniffing, such as sniffing harder or softer. And that meant it could have applications for locked-in patients. "We thought you could use this sniff to control anything, " Sobel says. "You could even fly a plane." © 2010 American Association for the Advancement of Science.

By Matt Walker Bowhead whales have a previously undiscovered ability to smell the air. The finding could change our understanding of how baleen whales locate prey, as scientists suspect the bowhead whales sniff out krill swarms. The whales' sense of smell was revealed when scientists dissected their bodies and found olfactory hardware linking the brain and nose, and functional protein receptors required to smell. Previously, whales and dolphins were thought to lack the ability. Details are published in the journal Marine Mammal Science. Cetacean expert Professor Hans Thewissen of the Northeastern Ohio Universities College of Medicine and colleagues based in Japan and Alaska made the discovery while evaluating the brain size of bowhead whales. The whales had been landed as part of the biannual Inupiat subsistence hunt along the north coast of Alaska, and Prof Thewissen's team was allowed to dissect the brain cavities, to evaluate how much of the brain casing a bowhead whale's brain actually fills. "Upon taking a brain out, I noticed that there were olfactory tracts, which, in other mammals, connect the brain to the nose," Prof Thewissen told the BBC. "I followed those to the nose, and noted that all the olfactory hardware is there." BBC © MMX

By Sandra G. Boodman As he picked up the phone to make the call, Wayne Curtis worried that his doctor might think he was a hypochondriac. Three weeks earlier, Curtis, then 48, had consulted Baltimore internist Charles Locke about a pulled muscle. Now the real estate agent had a new and seemingly trivial complaint: He couldn't hear anything out of his left ear, which seemed blocked. Curtis assumed that his problem was related to the thick coating of tree pollen that blanketed his downtown Baltimore neighborhood. Normally Curtis, who has long battled spring allergies, would have toughed it out and waited several weeks to see if his hearing returned as the pollen counts dropped. But a newly formed choral quartet of which Curtis was a member was about to have its first concert, and the tenor, who has performed with the Boston Symphony Orchestra, was concerned that his impaired hearing was affecting his singing. "I expected him to put me on a stronger decongestant, not to tell me to come in the very next day," said Curtis, who was taken aback by Locke's emphatic response. "It's probably a classic case of 'It's better to be lucky than good,' " Locke quipped. His sense of urgency was fueled by a memorable patient he had seen more than a decade earlier. Curtis's season of misery was as perennial as the pollen, and he was accustomed to loading up on antihistamines and decongestants every spring to get through it. © 2010 The Washington Post Company

When a person loses his sense of smell, does he also lose any memory associated with a smell? —Ana Artega, via e-mail David Smith, a professor of psychology and a researcher at the Center for Smell and Taste at the University of Florida, replies: Normally people can detect a cacophony of odors using the 40 million olfactory receptor neurons that reside in the nasal cavity. When we encounter a new odor, these neurons send information about the whiff to a brain area called the olfactory cortex, leaving an imprint of the smell there. These memories accumulate over time to create a library of odors. Although we do not fully understand how the olfactory cortex encodes these memories, we do know that olfactory memories seem to be particularly rich—perhaps because the olfactory cortex is closely connected to the brain regions important for recollection. These areas include the amygdala, which processes emotions, and the hippocampus, which encodes and stores memories. Damage to the olfactory receptor neurons because of a respiratory infection, a head injury or a neurodegenerative disease can disrupt the brain’s ability to process different smells. When olfactory neurons stop working altogether, a person develops anosmia, or the inability to discern odors. According to a 2008 report from the National Institutes of Health, 1 to 2 percent of the U.S. population younger than 65 years old, and more than half older than 65, have almost completely lost their sense of smell. © 2010 Scientific American,

The undersea world isn't as quiet as we thought, according to a New Zealand researcher who found fish can "talk" to each other. Fish communicate with noises including grunts, chirps and pops, University of Auckland marine scientist Shahriman Ghazali has discovered according to newspaper reports Wednesday. "All fish can hear, but not all can make sound -- pops and other sounds made by vibrating their swim bladder, a muscle they can contract," Ghazali told the New Zealand Herald. Fish are believed to communicate with each other for different reasons, including attracting mates, scaring off predators or orienting themselves. The gurnard species has a wide vocal repertoire and keeps up a constant chatter, Ghazali found after studying different species of fish placed into tanks. On the other hand, cod usually kept silent, except when they were spawning. "The hypothesis is that they are using sound as a synchronization so that the male and female release their eggs at the same time for fertilization," he said. Some reef fish, such as the damselfish, made sounds to attempt to scare off threatening fish and even divers, he said. But anyone hoping to strike up a conversation with their pet goldfish is out of luck. © 2010 Discovery Communications, LLC.

by Laurie Rich, Jane Bosveld, Andrew Grant, Amy Barth The brain is a castle on a hill. Encased in bone and protected by a special layer of cells, it is shielded from infections and injuries—but also from many pharmaceuticals and even from the body’s own immune defenses. As a result, brain problems are tough to diagnose and to treat. To meet this challenge, researchers are exploring unconventional therapies, from electrodes to laser-light stimulation to mind-bending drugs. Some of these radical experiments may never pan out. But, as frequently happens in medicine, a few of today’s improbable approaches may evolve into tomorrow’s miraculous cures. 1. Man Meets Machine In a sense, cyborgs already walk among us: Nearly 200,000 deaf or near-deaf people have cochlear implants, electronic sound-processing machines that stimulate the auditory nerve and link into the brain. But even by the fanciful science fiction definition, the age of cyborgs is just around the corner. In the last decade, researchers have become increasingly skilled at detecting and interpreting brain signals. Technologies that allow people to use their thoughts to control machines—computers, speaking devices, or prosthetic limbs—are already being tested and could soon be available for widespread applications.

Researchers conclude men are more attracted to women wearing pheromones, resulting in more formal dates, kissing, affection, sexual intercourse SAN FRANCISCO, — Women’s perfume laced with synthetic pheromones acts as a sexual magnet and increases the sexual attractiveness of women to men, San Francisco State University researchers conclude in a study appearing in the current issue of the quarterly journal Physiology and Behavior. The study, the first of its kind to independently test a sex attractant pheromone for women, showed that of the 36 women tested, 74 percent of those wearing their regular perfume with the pheromone saw an overall increase in three or more of the following sociosexual behaviors: frequency of kissing, heavy petting and affection, sexual intercourse, sleeping next to their partner, and formal dates with men. In contrast, only 23 percent of the women who had a placebo added to their perfume saw an increase in these sociosexual behaviors. Researchers conclude from these data that the pheromone users were more sexually attractive to men.

COLUMBUS, Ohio -- Musicians who hear the music they are performing while learning a new piece have a better memory for the music later, a new study suggests. But after they learn a song, actually hearing the music as they play does not improve the accuracy of their performance. These results shed new light on how memory works and on theories about how people learn, said Caroline Palmer, co-author of the study and professor of psychology at Ohio State University. Specifically, Palmer said the findings cast doubt on the universality of matching theories – theories that state memory works best when conditions are similar during learning and during recall of the information.

Cassowaries’ low-frequency sounds may give insight into dinosaur communications NEW YORK -- A family of huge forest birds living in the dense jungles of Papua New Guinea emit low-frequency calls deeper than virtually all other bird species, possibly to communicate through thick forest foliage, according to a study published by the New York-based Wildlife Conservation Society. Published in the recent issue of the scientific journal The Auk, the study says that three species of cassowaries – flightless birds that can weigh as much as 125 pounds – produce a "booming" call so low that humans may not be able to detect much of the sound. The researchers draw similarities between the birds' calls and the rumbling elephants make to communicate. "When close to the bird, these calls can be heard or felt as an unsettling sensation, similar to how observers describe elephant vocalizations," said WCS researcher Dr. Andrew Mack, the lead author of the study.

Memory slipping, Thelma Walton strains to read, something she had no trouble with five years ago. Her husband, Jim, prompts her every morning with simple math equations and writing tasks, constantly repeating patterns laid in her brain long ago. Now hard at this work, the promise of retirement and a leisurely everyman's every day is no longer theirs to enjoy. For Thelma and Jim, her Alzheimer's disease is fresh at every waking. "It's a frustrating disease," says Jim, a seventy-something retiree living in Raleigh, North Carolina. "You see a whole body and you expect that whole body to perform like it always did and it's not going to do that. The mind's not going to function that way." Slowly, as Alzheimer's creeps through the brain, it's likely to first affect something we take for granted: our library of smells. "Identifying smells involves not only perceiving the smell but comparing against your bank of smells in the brain," explains D.P. Devanand, a memory disorder researcher and co-director of the Memory Disorders Center at the New York State Psychiatric Institute. "People lose their memories for the smells that they had all their lives." Now, Devanand and a team of researchers have developed a simple scratch and sniff smell test aimed at detecting Alzheimer's early on, when olfactory memory wanes as a small brain area beneath the medial temporal lobe—it directs smell—starts accumulating tangles of stringy protein strands. © ScienCentral, 2000- 2004

The best place to sell magazines could be in the gym locker room, according to a study which found that pheromones in male sweat makes men opt for a manly read. Men under the influence of androstenol – a pheromone found in men’s underarm sweat – find men’s lifestyle magazines to be more attractive and are more likely to purchase them than those not exposed to the pheromone, suggests the research. Michael Kirk-Smith, from the University of Ulster, UK, and Claus Ebster, from the University of Vienna, Austria showed 120 student volunteers three magazines: the female lifestyle magazine Allure, the neutrally pitched National Geographic, and the male lifestyle magazine Men’s Health. The students were split into two groups with equal numbers of men and women. The first group wore a mask sprayed with androstenol and the second wore a mask permeated with a control solvent. The concentrations of the solvents in the masks were low enough as to have imperceptible odour to the wearers. The two groups were asked to rate the magazines according to how masculine they found each, how appealing and how likely they were to purchase them. The male participants exposed to androstenol rated Men’s Health as significantly more masculine and more appealing compared with the control group. They also had a higher tendency to report that they might buy the magazine. Women appeared to be completely unaffected by the pheromone. © Copyright Reed Business Information Ltd.

Chapter 9. Hearing, Vestibular Perception, Taste, and Smell