Features

 January sees the release of The King's Speech, a movie in which Colin Firth stars as George VI, portraying the King's struggle to overcome his stutter.

But how much do we understand about the processes that cause stuttering?

Yesterday, Kate Watkins of Oxford University's Department of Experimental Psychology presented new research at the Neuroscience 2010 conference into the brain activity of people who stutter and how it differs from the brain activity of other people during reading and listening.

I asked Kate about her latest work and how close we are to understanding what causes this condition...

OxSciBlog: What had previous research found out about the brain activity of people who stutter?
Kate Watkins: Previous studies have scanned the brains of people who stutter while they speak out loud in the scanner. Several abnormal patterns of activation are seen under these conditions: people who stutter activate right hemisphere regions that are homologous with regions active during speech production in the left hemisphere; brain regions responding to the speech sounds produced (auditory cortex) tend to be underactive in people who stutter compared to fluent speakers; subcortical brain regions involved in movement planning, sequencing, timing and execution (eg the basal ganglia and cerebellum) are typically overactive during speech production in people who stutter.

The majority of studies done previously have used overt speech production. This may or may not have included stuttered speech in the people who stutter (one curious effect of scanning that we observed was a reduction in stuttering when speaking inside the scanner). Using overt speech production raises some problems for data acquisition but, more importantly, it is not possible to tell if the abnormal patterns of speech production are a cause or a consequence of stuttered speech. 

OSB: How did you study brain activity in this new research?
KW: We used functional MRI to scan the brains of people who stutter and fluent speaking control participants during three conditions: (i) while they listened to sentences; (ii) while reading sentences silently; (iii) while reading sentences and listening to the same sentence being read by someone else. We wanted to know if the same patterns of abnormal brain activity would be seen in people who stutter even when they are not producing speech.  

OSB: What differences did you find in brain activity between people who stutter and non-stutterers?
KW: We found abnormal patterns of activation in people who stutter in auditory and motor brain areas but these patterns were different to those seen previously and during speech production. In contrast with previous findings, the auditory areas of the brain that responded to listening to other people speaking showed more activity in the people who stutter than the controls; when listening to self-produced speech this region typically had less activity in stutterers than in controls.

Together these findings suggest the reactivity of the auditory system is abnormal in stutterers. When reading, people who stutter showed abnormally reduced activity in a motor circuit that included the left inferior frontal gyrus, putamen and supplementary motor area. The activity in this motor circuit was reduced even further when listening to speech. This circuit is involved in initiating and sequencing of movement.

Even though the people in our study didn't produce any movements related to speech, this circuit is still involved in internal speech and its activity is abnormal in people who stutter. Our findings can therefore be considered to be characteristic of the stuttering brain rather than simply reflecting differences related to stuttered speech production. 

OSB: What is the next stage in your research?
KW: Next we want to look at the circuitry between the abnormal brain regions in more detail. The integration of auditory information in the motor system seems to be important for highlighting the functional abnormalities that we saw. We want to look further also at how the known fluency enhancers work in people who stutter - that is we need to figure out their mechanism of action in the brain and possibly implement methods for improving the therapeutic efficacy of this enhancement. 

OSB: What other research needs to be done if we are to understand what causes stuttering?
KW: Longitudinal studies starting early in childhood when stuttering starts are required. Ideally, we would like to study children soon after they start to stutter and follow up those who spontaneously recover and those that persist in stuttering. Genetic studies also have potential to shed light on the causes of this disorder. Mutations in three genes have been identified already that occur in about 10% of people who stutter but how they cause stuttering is unclear.  

So why do so many people end up at risk from such natural hazards? And is there anything scientists can do to help limit the human cost?

I asked Kate Donovan, from Oxford University's Department of Earth Sciences, about her experiences studying responses to Mount Merapi and about research at Oxford into hazard communication...

OxSciBlog: What are the challenges involved in communicating risks from natural hazards?
Kate Donovan: A proactive and prepared society is likely to be more resilient to a hazard event. But in order for that community to be prepared they must firstly accept that they are at risk and secondly have the resources available to be prepared. But many societies are vulnerable because they are poor and don't have access to these resources. Tragically, between 1991-2005, over 90% of deaths resulting from natural hazards occurred in developing countries.

How people perceive their own risk will influence their motivations and actions before and during an event. It is not a simple case of providing more information to at risk communities but instead requires a complex and long term change in culture towards the hazard.

Another important element of risk perception and communicating risk is trust. If civil authorities or scientists are not trusted then risk communication will break down. Trust relies on various elements including local culture, political history, the mismanagement of past events and false alarms. In Indonesia past political turmoil has brought extreme suffering and therefore the population tend to be suspicious of authority. During a visit to Mt Merapi volcano last year, local people told me that they would never evacuate because they did not trust the local authorities, indeed some villagers would rather rely on their own knowledge of the volcano and their traditional warning signs.

OSB: What did you learn from your work on Mt Merapi?
KD: The people who live high on the slopes of Mt Merapi are at extreme risk from the regular eruptions that occur at this very active volcano. The current eruption is an example of this volcano's potential for destruction and the local populations’ vulnerability. The villagers living on the volcano have a great respect for Mt Merapi and many (especially in the more isolated regions) believe that the volcano is home to supernatural creatures that have the power to control eruptions. These creatures can also provide warnings before an eruption and therefore protect certain communities, if those communities respect the creatures. The rich culture linking the people to the volcano provides a coping mechanism, a way of explaining and living with the dangers they face.

In the news at the moment there are images of people being rescued from the volcano. Most of those who were initially killed or are badly injured were most likely returning to their homes and villages during the evacuation to tend to abandoned livestock. These extremely poor communities rely on subsistence farming and their livestock are all they have. Returning during the day to their homes to collect grass for their cattle is considered entirely acceptable. These people have to balance the risk between definitely losing their income if their livestock starve or possibly losing everything in an eruption. It is so sad that these wonderful, intelligent and kind people are now homeless and suffering.

OSB: How did these experiences influence your current research?
KD: My experiences at Mt Merapi were life changing. Living with those who have so little and yet fed and housed me for months was humbling and made me even more determined to have a career in disaster risk reduction. So after completing my PhD at the University of Plymouth in January this year I searched for research opportunities that focussed on practical interdisciplinary opportunities. I was delighted to find a project within the Department of Earth Sciences here at the University of Oxford that is actively engaging with local authorities to reduce the impact of flood hazard. My current research is focused much closer to home as I am currently working on Project FOSTER that aims to bridge the gap between local authorities in the UK and flood science.

OSB: Why is it vital to combine physical & social science approaches?
KD: Disasters occur at the interface of society and nature, in other words a disaster does not occur unless a hazard interacts with society resulting in death or economic loss. Therefore in order to reduce the risks people face it is essential that disaster research explores both sciences. It is easier to consider interdisciplinary research as focussing on finding a solution using the best available methods from both the physical and social sciences. With a growing global population and the potential threat of climate change increasing the number of extreme hazard events there is a growing need for researchers with a fluency in both sciences and universities across the world are slowly responding to this.

Various institutes have been created to bring disciplines together and the University of Oxford is a good example of this with large initiatives such as The Smith School of Enterprise and the Environment and also the Oxford Martin School, but also smaller enterprises such as The Hazards Forum.

OSB: How do you hope hazard communication research at Oxford will develop?
KD: A challenge for any institution is cross-disciplinary communication and collaboration. Universities have conventionally created disciplinary silos and so topics that span disciplines, such as hazard and disaster research, tend to fall between fields. But recently, with a move from research funders towards more accountable research and communicating science to a wider audience, Universities must encourage interdisciplinary collaborations and effective dissemination of results.

At Oxford there are many initiatives that encourage collaborations and one of these is the new Hazards Forum that aims to bring researches together from across the university who are interested in hazards and disaster research. This Forum provides an opportunity for communication, collaboration and learning between subjects and was founded jointly by colleagues in the Department of Earth Sciences and The School of Geography and the Environment. Hopefully hazard communication between subjects will encourage practical and effective research that will improve the quality of life of those living in hazard regions.

Dr Kate Donovan is based at Oxford University's Department of Earth Sciences.

What links different pollinating insects in your garden or sea otters and kelp?

In a recent paper in Royal Society B Becky Morris of Oxford University's Department of Zoology explored how species interactions create networks in which apparently unconnected organisms can affect one another.

I asked Becky about how these networks work and what the possible implications are for how we attempt to conserve biodiversity around the world...

OxSciBlog: How are species organised in networks?
Becky Morris: Species don’t exist in isolation; they are each linked to one or more other species, with which they interact in a variety of different ways, for example as predators or pollinators.

Think of them as being like web sites (the species) arranged on the World Wide Web (the network). For example, all the insects that pollinate flowers in your garden, along with the flowers that they pollinate, could be considered as a relatively discrete network (although they would also interact with species outside this network).

OSB: Why is understanding such networks important?
BM: Because species are organised in networks, any perturbation to one species is likely to have a knock-on effect on many other species in the network, including those with which it interacts only indirectly. Indirect interactions occur when one species affects a second species through one or more intermediate species. Through such indirect interactions, species that are not closely linked can affect each other, something that you would not predict without considering network structure.

A good example of this is in Pacific kelp forests, where sea otters feed on sea urchins. In areas where sea otters have been hunted to extinction, there has been a huge increase in their prey, sea urchins, which has resulted in the urchins overgrazing and decimating kelp forests. The sea otters have indirectly affected the kelp, via the intermediate sea urchins.

OSB: How might it change our approach to conserving biodiversity?
BM: Rather than focusing on conserving species it might be better to focus on conserving networks of species and their functions. In practice this would be extremely challenging. It is really only possible to ensure that the species that are involved in the networks are present; it is not possible to make them interact.

This has has been demonstrated in a recent study in restored heathlands in Dorset, where individual species of plants, bumble bee pollinators and their natural enemies were successfully restored, but the interactions between the bumble bees and certain natural enemies were not reestablished, so the network structure was not restored to how it was in ancient heathland sites.

However, a network approach can be used to evaluate the impacts of practices such as habitat management and biological control, and these practices indirectly affect biodiversity. A network approach will lead to much greater insight than if only species were monitored, but as yet we have no way of actually focusing our conservation efforts on the interactions between species, rather than the species themselves.

OSB: What impact could human activity have on these networks?
BM: Human activities such as deforestation, habitat fragmentation or climate change all have the potential to alter or disrupt network structure, which in turn will affect their susceptibility to species loss, and the functioning of ecosystems.

A recent study led by Jason Tylianakis from Canterbury University in New Zealand revealed changes in network structure for insect communities in coastal Ecuador, along a gradient of habitat modification from the original forest habitat, through coffee agroforest, to the most modified pasture and rice fields. Surprisingly species richness did not change along this gradient of habitat disturbance, so if we looked only for changes in species richness we would not see any effect.

OSB: What future research is needed in this area?
BM: More experiments and theoretical studies are needed, taking into account the variability of the real world. We still don’t understand exactly how networks respond to perturbations, and whether there are critical thresholds at which the loss of species leads to the loss of network structure and functioning (and whether they can be restored). We need to be able to make general predictions, rather than have a case-by-case understanding.

Dr Rebecca Morris is a Royal Society University Research Fellow based at Oxford University's Department of Zoology.

With Halloween almost upon us we thought we should give you a scare of the eight-legged variety.

So I asked George McGavin, of the Oxford University Museum of Natural History, about scary spider encounters and why arachnids deserve gasps of wonder along with our yelps of fear...

OxSciBlog: What has been your favourite encounter with a spider?
George McGavin: My favourite encounter has got to be when I found the goliath bird-eating tarantula (Theraphosa blondi) when filming Lost Land of the Jaguar in Guyana. We went out after dark to scour the forest close to base camp - after several hours we had not found anything and I was beginning to think that we'd never find one when Bruds, one of the rangers, radioed to say he had found a likely burrow.

Sure enough the burrow was occupied by a large female which I was able to coax out using a blade of grass as a lure. Once in the open I blocked the hole with my machete. The spider was the size of a soup plate and although equipped with half inch long fangs, their main defence is to flick tiny harpoon-like hairs in the face of any attacker. This she did with great enthusiasm and the air was soon filled with her abdominal hairs. They got in my face, eyes and throat but I was not going to be deterred.

When she had calmed down I gently picked her up to show to the camera. She was a real star and even leapt off my hand towards the cameraman - a great performance!

OSB: In evolutionary terms how successful are spiders?
GMcG: Arachnids appeared on Earth around 420 million years ago. Today there are about 80,000 species worldwide. They are a very old group and include things like mites, ticks, scorpions, whip-spiders, harvestmen and pseudoscorpions. The true spiders have mastered the use of silk for prey capture, transport, protection and other uses.

OSB: How important are spiders to preserving ecosystems?
GMcG: As terrestrial carnivores arachnids they have a huge impact on populations of insects and other small invertebrates. A hectare of grassland may be home to several million spiders and other arachnids. One species lives in water in a specially constructed silk diving bell and can prey on small fish fry. Recently the first herbivorous spider has been discovered.

OSB: Why do you think many people have a fear of spiders?
GMcG: In the UK 7 million people are arachnophobic to some degree. While it is true that there are a dozen or so species of spiders whose fangs are strong enough to break human skin they will not do you any harm and allergic reactions to spider bites are very rare.

In Australia, however, where there are several dangerous species, people seem a bit more relaxed about their eight-legged friends. In the middle ages in Europe spiders were associated with diseases and death and I wonder if this might be might origin of our phobia.

OSB: What do scientists still need to find out about spiders?
GMcG: While the arachnids are not as diverse as the insects there are still many more species waiting to be discovered. We actually know very little about the lives of most spider species.

 Dr George McGavin is an Honorary Research Associate at the Oxford University Museum of Natural History. 

Tiny flashes of blue light from beneath the icy South Pole could help scientists uncover the origins of cosmic rays and neutrinos.

These flashes occur when neutrinos created by cosmic rays strike nuclei in the ice, releasing energetic muons which travel through the ice faster even than light can -  producing a burst of Cherenkov radiation. This is detected by IceCube, a 'telescope' made up of thousands of optical sensors buried up to 2.5km deep in the Antarctic icecap. This location is ideal because under the huge pressure at such depths the ice is free of air bubbles and very clear.

Subir Sarkar of Oxford University's Department of Physics leads the British involvement in IceCube, he told The Telegraph's Richard Gray: 'Cosmic rays were discovered 100 years ago, but we still have no idea where they come from. At first glance, IceCube seems like a crazy experiment. How can you study the sky when you bury your detectors a mile beneath the ice? But it gives us a new way of tracing their paths back to their source.'

'The real excitement is that neutrinos and cosmic rays will reveal an entirely new way of looking at the universe and allow us to see into places where we haven't been able to before.'

'Currently we have no way of peering into black holes through the dust and gas that surrounds them, so if high energy neutrinos are being emitted from their fringes, then we can 'see' into places we haven't been able to before.'

IceCube isn't due to be completed until 2011, when all the optical sensors will have been installed, but as early as 2006 its detectors began to pick up the flashes of neutrino collisions. It's already identified an area of the sky near the constellation of Vela as a prolific source of cosmic rays.

Being able to spot these very rare neutrino collisions could help us understand the nature of the dark matter thought to make up around 23% of our Universe.