Hacking our senses to boost learning power

Some schools are pumping music, noises and pleasant smells into the classroom to see if it improves exam results. Could it work? Why do songs stick in our heads? What does your school smell like? Is it noisy or peaceful?

It might not seem important, but a growing body of research suggests that smells and sounds can have an impact on learning, performance and creativity. Indeed, some head teachers have recently taken to broadcasting noises and pumping smells into their schools to see whether it can boost grades. Is there anything in it? And if so, what are the implications for the way we work and study?

There is certainly some well­established research to suggest that some noises can have a harmful effect on learning. Numerous studies over the past 15 years have found that children attending schools under the flight paths of large airports fall behind in their exam results. Bridget Shield, a professor of acoustics (声学) at London South Bank University, and Julie Dockrell, from the Institute of Education, have been conducting studies on the effects of all sorts of noises, such as traffic and sirens (汽笛), as well as noise generated by the children themselves. When they recreated those particular sounds in an experimental setting while children completed various learning tasks, they found a significant negative effect on exam scores.

“Everything points to a bad impact of the noise on children’s performance, in numeracy, in literacy, and in spelling，” says Shield. The noise seemed to have an especially harmful effect on children with special needs.

Whether background sounds are beneficial or not seems to depend on what kind of noise it is - and the volume. In a series of studies published last year, Ravi Mehta from the College of Business at Illinois and his colleagues tested people’s creativity while exposed to a soundtrack made up of background noises - such as coffee­shop chatter and construction­site drilling - at different volumes. They found that people were more creative when the background noises were played at a medium level than when volume was low. Loud background noise, however, damaged their creativity.

Many teachers all over the world already play music to students in class. Many are inspired by the belief that hearing music can boost IQ in later tasks, the so­called Mozart effect. While the evidence actually suggests it’s hard to say classical music boosts brainpower, researchers do think pleasant sounds before a task can sometimes lift your mood and help you perform well, says Perham, who has done his own studies on the phenomenon. The key appears to be that you enjoy what you’re hearing. “If you like the music or you like the sound - even listening to a Stephen King novel - then you do better. It doesn’t matter about the music，” he says.

So, it seems that schools that choose to prevent disturbing noises and create positive soundscapes could enhance the learning of their for students, so long as they make careful choices. Yet this isn’t the only sense being used to affect learning. Special educational needs for students at Sydenham high school in London are being encouraged to revise different subjects in the presence of different smells - grapefruit scents for maths, lavender for French and spearmint for history.

Some people can sit outside all summer long and not suffer from mosquito bites, while others turn into an itchy (痒的) mess despite bathing in DEET (含驱蚊胺的沐浴露) and never leaving the purple light of the bug zapper (灭蚊灯). It’s mostly about the invisible chemical landscape of the air around us. Mosquitoes take advantage of this landscape by using specialized behaviors and sensory organs to find victims by following the tiny chemical marks their bodies leave behind; specifically, mosquitoes rely on carbon dioxide to find their hosts.

When we breathe, the carbon dioxide from our lungs doesn’t immediately mix with the air, but temporarily stays in plumes (团状气流) that mosquitoes follow. “Mosquitoes start locating themselves in those pulses of carbon dioxide and keep flying upwind as they sense higher concentrations than the normal atmosphere contains,” said Joop van Loon, a scientist who studies insects. Using carbon dioxide, mosquitoes can lock onto targets from up to 164 feet (50 meters) away.

Things start getting personal when mosquitoes get about 3 feet (1 meter) away from a group of potential targets. At a short distance, mosquitoes take into account a lot of factors that vary from person to person, including skin temperature, the presence of water vapor (水蒸气) and color. Scientists think the most important factor mosquitoes rely on when choosing one person over another is the chemical compounds (化合物) produced by the colonies of microbes (微生物菌落) that live on our skin.

These chemical smells are complex, including upward of 300 different compounds, and they vary from person to person based on genetic variation and environments. “If you compare a father and daughter in the same household, there can be differences in the ratios of the chemicals the microbes are making,” said Jeff Riffell, an associate professor of biology who has studied mosquito attraction. For instance, men with a greater diversity of skin microbes tended to get fewer mosquito bites than men with less diverse skin microbes did, a study found.

Tiny differences in the elements of these chemical smells can account for big differences in how many bites a person gets. The elements of those microbial colonies can also vary over time in the same individual, particularly if that person is sick, Riffell said. We don’t have much control over the microbiomes on our skin, but Riffell did offer some advice based on his research — mosquitoes love the color black, so consider wearing something lighter at your next cookout.

Common sense suggests that the bigger the animal, the greater number of cells—and therefore the greater chance of developing cancer. However, in the 1970s an Oxford University professor, Richard Peto, found that: the bigger animal, the less cancer. 

Scientists call it Peto’s paradox: cancer is caused by gene mutations(突变) that increase in cells over time, yet long-lived animals that have lots of cells, such as elephants and whales, hardly ever get it. Why? For elephants, at least, part of the answer may be the gene commonly known as p53, which also helps humans and many other animals repair DNA damaged during replication(复制). Elephants have an amazing 20 copies of this gene. Those copies, each with two variations called alleles, produce a total of 40 proteins, compared with humans’ and most animals’ single copy producing two proteins.

New research in Molecular Biology and Evolution looks into how elephants’ many copies offer cancer-fighting advantages. The work “opens many new possibilities to study how cells protect themselves from a damaged genome,” says co-author Robin Fåhraeus, a molecular oncologist at France’s National Institute of Health and Medical Research. In mammals, p53 plays a significant role in preventing mutated cells from turning into tumors. It works by pausing replication and then either starting repair or causing cells to self-destroy if the damage is huge. Without action from p53, cancer can easily take hold.

The scientists modeled and examined elephants’ 40 p53 proteins finding two ways the gene could help elephants avoid cancer. First, that elephants possess multiple copies lowers the chance of p53 no longer working because of mutations. Additionally, elephants’ p53 copies activate in response to varying molecular triggers(触发器) and so respond to damaged cells differently, which likely gives an edge when detecting and clearing away mutations.

These “remarkable” results imply that elephants have a series of means through which p53 can operate. This points to exciting possibilities for exploring powerful new approaches to cancer protection in humans.