human body Archives | Research & Innovation

Professor Jennifer Steeves in Centre for Vision Research finds face blindness sufferers better at recognizing voices

fmaquito — Fri, 22 Oct 2010 08:00:00 +0000

People who can no longer recognize faces compensate with heightened voice recognition abilities, says a 91��ɫ study, which also finds that our brains may identify people and things on separate neurological planes.

The study, recently published in the journal Neuropsychologia looked at a rare disorder called prosopagnosia, in which the ability to visually identify faces is lost or severely impaired.

Researchers performed a series of experiments that gauged prosopagnosia sufferers' recognition of faces, objects and voices and other sounds, both separately and in varying combinations; the scientists compared these results to those of control subjects with normal brain functioning.

"We were interested in investigating the interactions between different types of sensory inputs," says lead researcher Jennifer Steeves (left), a professor of psychology in 91��ɫ’s . "For example, does seeing a person’s face and listening to them speaking at the same time offer more helpful information to identify that person, or is a single sensory input superior?"

Steeves’ experiments involved a patient who suffered brain damage from meningitis as a child. With extensive lesions on the right hemisphere and most of the ventral visual areas, he was unable to recognize familiar faces, facial expressions, objects, colours or words.

"Quite remarkably, even with these deficits, he was able to hold a job and maintain an independent lifestyle," Steeves says. "We wanted to find out what cognitive functions were compensating to help him achieve this."

In one experiment, participants were required to rapidly learn the identities of 10 individuals,��using an image of a face paired with a voice.

Prior to this exercise, subjects were presented with grey-scale images of 110 female faces that had been stripped of distinguishing features. They were also fed auditory stimuli – a 20-second neutral passage spoken in English by one of 110 female voices. Participants were then tested on what they had learned in visual and auditory-only modes, and in combination.

Steeves and her colleagues found that control subjects relied more heavily on visual cues, while the patient with prosopagnosia used auditory information more expertly to recognize people. However, auditory cues didn’t help in identifying objects, leading researchers to believe that our processing of people and things occur in two different neurological pathways.

Untangling this web of sensory cues is important on more than one level, Steeves notes. "Our hope is that it will help not only our understanding of those with brain disorders, but also to understand how healthy brains function," she says.

The study, "Superior voice recognition in a patient with acquired prosopagnosia and object agnosia," is co-authored by Adria Hoover, a 91��ɫ psychology graduate student, and Jean-François Démonet, director of France’s Institut National de la Santé et de la Recherche Médicale (INSERM).

Steeves is one of the researchers based in 91��ɫ’s new state-of-the-art Sherman Health Science Research Centre, which officially opened on Sept. 14. She leads the Perceptual Neuroscience Laboratory, which is based on the building’s main level. Both Steeves and her lab are part of the .

The research was funded by the and France’s .

By Melissa Hughes, media relations officer. Republished courtesy of YFile– 91��ɫ’s daily e-bulletin

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Audio: 91��ɫ Prof on bilingualism, Alzheimer's disease and maintaining an active mind

fmaquito — Tue, 30 Mar 2010 08:00:00 +0000

Ellen Bialystok, Distinguished Research Professor of Psychology in 91��ɫ's , spoke to Radio Canada International's "The Link" March 26 about her research on bilingualism and Alzheimer's disease. starts 12 minutes into the episode and runs for six and a half minutes to the 18:30 mark.

Bialystok also spoke to the March 27 about research helps keep you mentally fit, although there are "more questions than answers" on whether it can help delay or prevent dementia or Alzheimer's.

Posted by Elizabeth Monier-Williams, research communications officer, with files courtesy of YFile – 91��ɫ University’s daily e-bulletin.

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Video: 91��ɫ study from Centre for Vision Research finds Olympic athletes may seem faster in red

fmaquito — Thu, 25 Feb 2010 10:00:00 +0000

Wearing red at the Olympics may give an athlete an easy advantage, according to a 91��ɫ study that shows perceptions of motion are subconsciously affected by colour.

“All things being equal between two figure skaters – including their actual speed on the ice – the judges will perceive a skater in red is moving with greater speed than a skater in blue, and may reward the skater in red with higher marks,” says Mazyar Fallah, a professor in the School of Kinesiology & Health Science in 91��ɫ’s Faculty of Health.

Above: The 2010 Canadian Olympic team in their red uniforms. Photo: Wikimedia Commons.

The study, conducted by Fallah and co-author Illia Tchernikov in 91��ɫ’s Centre for Vision Research, was published today by the the Public Library of Science open access peer-reviewed journal .

Their research on visual processing found that people’s eyes more quickly follow a red target on a computer screen more quickly than a green, yellow or especially a blue target.

VIDEO--The Daily Planet covered . The clip runs approximately 20 seconds and begins at the 7:50 mark.

“In sports, the outcome of a competition is supposed to depend on the abilities of the players, rather than the colours they are wearing,” says Fallah. “However, our research shows it may make sense to wear red in a sport such as figure skating, in which you want to be perceived as quick. In contrast, it may be best to wear another colour in a sport in which a referee is handing out penalties.”

The finding that there is a colour hierarchy that automatically guides the selection of what someone will focus on has implications for many sports such as figure skating and gymnastics in which speed may be perceived by a judge rather than measured in milliseconds, Fallah says. It may also be important for other fields such as advertising, in which capturing attention is paramount, and in designing human-computer interfaces that are effective, he said.

Left: Canadian figure skating champion and Olympic competitor Joannie Rochette. Photo: Wikimedia Commons.

Five subjects took part in the study, with each completing about a thousand tests. Each participant automatically focused on targets on the screen and all produced the same colour hierarchy, choosing red targets first, followed by green, yellow and blue. This suggests, says Fallah, that the colour hierarchy is inherent, either because of evolution – red is the colour of blood, whereas blue is the colour of the sky – or as a result of experience − red stop signs and traffic signals indicate danger.

Fallah's research was covered by and .

Republished courtesy of YFile – 91��ɫ’s daily e-bulletin.

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Cutting calories may accelerate ALS, 91��ɫ researchers suggest

fmaquito — Thu, 25 Feb 2010 10:00:00 +0000

Cutting calories may speed the progression of the fatal neuromuscular disease Amyotrophic Lateral Sclerosis (ALS) because of changes that occur at the molecular level, a study from 91��ɫ has found.

The research, which looked at the effects of caloric restriction in a mouse model of ALS, found that restricting caloric intake to 60 per cent of the usual mouse diet significantly hastened the onset and progression of ALS, as well as death. It is the first study to demonstrate that caloric restriction in animal models of ALS produces molecular-level changes that lead to cell death.

The study was published today by the open access peer reviewed journal Public Library of Science (). Former 91��ɫ graduate student Barkha P. Patel, supervised by assistant professor Mazen J. Hamadeh (left), led the research at 91��ɫ’s Muscle Health Research Centre, in collaboration with researchers at McMaster University.

“Research has shown that restricting calories can extend lifespan in animals, so we were surprised to find during an earlier study with the same animal model of ALS that it actually hastened the clinical onset of the disease,” said Hamadeh, of the School of Kinesiology and Health Science in 91��ɫ’s . “In this study, we set out to discover how caloric restriction actually led to changes at the molecular level.”

ALS, also known as Lou Gehrig’s Disease, is characterized by degeneration of motor neurons in the brain and spinal cord and is associated with an increase in oxidative stress – the physiological stress on the body that is caused by damage from free radicals that are not neutralized by antioxidants.

The study sought to unravel the mechanism behind the acceleration of the clinical onset and progression of ALS when calories are restricted. It found that caloric restriction shortens lifespan through an increase in protein involved in lipid damage, inflammation and cell death.

If the results from the animal model of ALS are extrapolated to patients with the disease, caloric restriction would be contraindicated, Patel said.

For more information about nutrition research in ALS at 91��ɫ, visit Hamadeh's Web site.

By Janice Walls, media relations coordinator. Republished courtesy of 91��ɫ Media Relations.

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Regular exercise can turn back the clock for aging muscle

fmaquito — Mon, 18 Jan 2010 10:00:00 +0000

It may not be the fountain of youth, but researchers at 91��ɫ have discovered that regular exercise can effectively turn back the clock for aging skeletal muscle.

The study,��“Molecular basis for an attenuated mitochondrial adaptive plasticity in aged skeletal muscle,” was recently published in the journal . The results indicate that the elderly are able to rebuild muscle mass,��and while they will not achieve the abs of a 20-year-old, they can reverse significant damage and loss of muscle function caused by inactivity and old age.

The research team led by Professor David Hood, Canada Research Chair in Cell Physiology and a professor in the School of Kinesiology & Health Sciences in 91��ɫ’s Faculty of Health, carried out the study as part of an ongoing series of investigations into the benefits of exercise (see YFile,��May 11, 2007 & March 2, 2009). This most recent study demonstrates that even in the elderly (individuals of 70 or 80 human years of age), regular exercise has the effect of rejuvenating muscle health, and these benefits are demonstrated by reduced fatigue and enhanced cellular function. The study adds weight to a growing body of findings by Hood and his research team that exercise plays a key role in achieving long-term health, even into advanced age.

Right: David Hood

“We found that muscle does adapt, but it takes a longer time for that adaptation to take place,” says Hood. “It is not a question anymore that regular exercise offers little benefit for elderly individuals because their muscles won’t adapt. That is not the case. The muscles of older individuals do adapt, they just don’t adapt as robustly or as quickly as younger individuals.”

Hood says the study showed that elderly muscle will continue to improve in its responsiveness as long as the exercise continues. "It may take more time but the benefits are definitely there," he says.

"To prove this, we used a well-established animal model of aging, the Fisher Brown Norway rat at young and very old ages. To avoid any differences in exercise behaviour between ages, we used a chronic stimulation model of muscle contraction in which the muscles of one leg were made to contract for three hours a day for seven consecutive days. This represents a standardized high exercise workload which can be imposed on one leg of both the young and old animals while the opposite leg remains at rest," explains Hood.

In cell biology, mitochondria are membrane enclosed organelles found in most cells of complex organisms. Mitochondria are sometimes described as the powerplants of cells because of their role in generating most of the cell's chemical energy. Mitochondria are involved in a variety of other processes,��such as signaling, cellular differentiation into tissues, cell death, as well as the control of the cell cycle and cell growth.

At the end of the seven-day period, the adaptability of the muscle with respect to its ability to withstand fatigue was assessed. Specifically, Hood's research team looked at key components of muscle cell health, including the production of mitochondria and proteins which are known regulators of mitochondrial synthesis. "While the older muscle fatigued more rapidly than the young muscle, this fatigue was reduced by the exercise and the muscle was 'rescued', allowing it to perform similarly to that of the young muscle," says Hood. In the younger muscle, regular exercise increased the mitochondrial content to a greater degree than in the old muscle, but old muscle did experience an increase and there was reduced apoptosis (cell death) in the old muscle.

Hood says the findings mean that exercise carries huge benefits for all ages, and muscle, no matter what its age, can adapt regardless of how old a person is. “People should be encouraged to exercise continually throughout their life,” says Hood. “Don't expect that as you get older, the adaptations will happen as quickly, but an ongoing lifestyle choice to exercise is very important.”

The benefits, says Hood, are many for the elderly include and include stronger muscles, greater resistance to injury and bone breakage, and enhanced metabolism. “Regular exercise means being less tired doing normal daily activities, improved metabolism which helps you break down fat making you more sensitive to insulin, which is important in preventing pre-diabetic conditions. Better metabolism improves whole body function and wellness.”

Muscle Health Research Centre

Hood's lab is part of 91��ɫ's new Muscle Health Research Centre (MHRC),��which is the first of its kind in Canada. The centre will celebrate its official opening on Wednesday, Jan. 20, at 10:30am.

“This centre is unique in that we’re zeroing in on skeletal muscle and its relationship to health, with a strong focus on what exercise can do,” says Hood,��who will serve as the centre's director. “We’re looking for new discoveries on how exercise can benefit Canadians through adaptations in the metabolism and structure of muscle.”

The MHRC conducts collaborative research with scientists from the School of Kinesiology & Health Science and the Department of Biology.

“Like all research centres at 91��ɫ, the MHRC has an interdisciplinary mandate – that is, enabling researchers from different departments and disciplines to work together towards a common goal,” says Hood.

Scientists from the MHRC are investigating topics such as muscle metabolism, muscle development and muscle adaptations to exercise, metabolic disease and cancer. Professor Tara Haas and colleagues in the MHRC recently identified a cell-signalling process that stimulates blood vessel growth and may help individuals with diabetes to exercise and thereby improve their health (see YFile, Nov. 17, 2009).

“As a leading research institution, we’re concerned with bringing the work of our scientists to bear on the real world and improving the health and well-being of Canadians,” says Harvey Skinner, dean of 91��ɫ's Faculty of Health. The centre will serve as an innovative hub for the life sciences within 91��ɫ’s Faculty of Health, generating new knowledge and disseminating research findings to the public and the health system.

The opening ceremony will feature guest speakers, including Olympic figure skater Barbara Underhill; Philip Gardiner, director of the Health, Leisure & Human Performance Research Institute at the University of Manitoba; and Jane Aubin, scientific director of the .

The opening will take place Jan. 20, from 10:30am to 1pm, in the Execultive Learning Centre located in X106 Seymour Schulich Building on 91��ɫ's Keele campus. For more information, contact Kathy Thomas at thomask@yorku.ca. To learn more about muscle health research at 91��ɫ, visit the MHRC Web site or contact Hood at dhood@yorku.ca.

By Jenny Pitt-Clark, YFile editor

Republished courtesy of YFile – 91��ɫ’s daily e-bulletin.

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91��ɫ's newest molecular biologist chases the mysteries of La

fmaquito — Fri, 08 Jan 2010 10:00:00 +0000

Although he doesn’t have many hobbies, biologist Mark Bayfield might consider taking up origami, based on the particular talents of his favourite research subject: the protein antigen known as La, one of the cell’s key regulators.

The La antigen is noted for its abundance and ubiquity in human cells, where it has several roles in RNA metabolism. It is thought to be a significant factor in helping cellular RNAs fold into their correct conformation, much like practitioners of the Japanese art of paper-folding copy objects in nature. Importantly, researchers suspect that several human viruses subvert this function of La in favour of their own RNA during infection.

Right: Mark Bayfield

As one of the newest members of the Faculty of Science & Engineering’s Department of Biology, Bayfield arrived one year ago to bolster 91��ɫ’s growing team of molecular biologists – researchers who are carrying the study of the human body beyond the sequencing of the genome into the even more complex world of cellular processes, in search of fundamental knowledge that will help find the causes and cures of disease.

“A lot of viruses really, really like La to help their genes get expressed,” Bayfield explains. “They hijack this protein from its normal job.”

“Viruses have evolved to mimic the normal substrates, the normal targets of La, so that it thinks the viral RNA is what it should be binding and doing things for. What we’re doing in this lab, in part, is to figure out what La is doing in these contexts.”

The implications of his work are of great interest to people in the medical community looking for ways to turn off the rogue processes in human cells that are responsible for the spread of diseases such as cancer, hepatitis B and C, poliovirus and rabies. In fact, La was discovered in the 1970s during research into the autoimmune disease Lupus. But, as in most fundamental research, it’s early days to be considering applications for what Bayfield is learning about La.

Left: Illustration of La

“We’re still at the stage where we’re trying to get under the hood and find out what it does,” he says. But he expects scientists at the major pharmaceutical companies will find applications for what he is learning and be able to use the data in the search for new ways of fighting disease.

Bayfield’s work is cutting edge. The was awarded, in part, to Professor Paul Nurse of the Imperial Cancer Research Fund in London, England, for his work on cellular processes using yeast as an experimental model. Bayfield also uses yeast cells to study La because of their rapid generation time and ease of use in genetics.

“Human proteins and the equivalent yeast proteins can sometimes do the same thing in a cell, and this is the case for La. You can literally take a human protein and put it into a yeast cell and it can often do the exact same job just as well.”

Bayfield began his career at Montreal’s McGill University where he did an undergrad thesis that opened his eyes to the joys and challenges of fundamental research. “In the textbook…you’re only reading about the stuff that works – that’s not how research gets done. They’re not telling you about all the things they did that didn’t work. But for me, that just makes it more rewarding when it does work.”

After graduate studies at Rhode Island’s Brown University studying bacteria and ribosomes, Bayfield did his post-doctoral research at the National Institutes of Health in Bethesda, Maryland, where he first started working with La.

Although he tried most branches of science at university and considered doing medicine, he found he enjoyed working out the puzzles of fundamental research and settled on molecular biology as his field. “It’s one of the subjects where I feel we’re really in the first few pages of a big book,” he explains. “We’re getting the tools now to get to a level of complexity that even 10 years ago – and certainly 30 or 40 years ago – we didn’t even imagine existed.”

For more information on Mark Bayfield’s research visit his Web page.

By David Fuller, YFile contributing writer

Republished courtesy of YFile – 91��ɫ’s daily e-bulletin.

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