Superstars of STEM: Watching the light of understanding
Lilach Avitan’s research may one day lead to better prosthetics and smarter AI. Dion Pretorius reports.
The medical and biological functions of the brain are fascinating, but often its most interesting property, computational power, is overlooked.
The human brain is extremely complex, with layer upon layer of processing grunt. Groups of neurons – called neural assemblies – set off electrical signals through these layers, and they travel around to activate different parts until perception is achieved and an action is executed.
However, due to this complexity and the immense number of neurons involved (about 100 billion), human brains are very hard analyse as a whole. To address this, researchers work with simpler versions instead, using animals such as the larvae of zebrafish (Danio rerio), which only have around 100,000 neurons.
Lilach Avitan is a research fellow at the University of Queensland in Australia, and she analyses a special breed of zebrafish that has a very useful genetic mutation. The fish are transparent at the larvae stage, which allows Avitan to watch their brains as they go about their business.
The fish also have indicators embedded in their neural assemblies that light up lights up whenever the they are active.
“This new technology allows us to watch the brain in action in a living, awake and intact animal,” Avitan explains.
With such access, she is able to record and analyse signals from hundreds of neurons in the fishes’ brains, recognising patterns and predicting activities.
“By looking at the patterns of brain activity and learning their statistics, we can accurately predict the stimulus which was delivered to the animal,” she explains.
“Recently we have shown that visual experience early in life changes the nature of activity patterns in the developing brain.
“We’re in the early stages, but eventually this field of research will give us the tools we need to design prosthetic limbs, called neuroprosthetics, and other technologies that are activated by nothing but brain activity.”
Avitan says we can also look at the way the brain processes information – which is extremely efficient – and apply these lessons to design computing devices as well as more sophisticated artificial intelligence algorithms.
“Deep learning is an example of where the brain has informed some really impressive developments in technology, and we’re only just scratching the surface,” she says.
However, the brain comes with its challenges.
One of these is called “spontaneous activity” – electrical activity that takes place in the absence of any external stimuli.
“We used to think that spontaneous activity was just background noise, but we are starting to learn that it is more,” she explains.
“It could be a way for our brains to prepare for an expected stimulus, a way for the brain to modulate attention; or it could be the brain’s way of testing new pathways to increase its efficiency especially during development.”
The phenomenon, she says, is still poorly understood, and serves as a reminder of just how much there is still to learn about the functioning of the brain.
“The better we understand how the brain functions, the greater the inspiration and impact it will have on our lives, the technology we use, and the innovations we can come up with,” she explains.
“That is why computational neuroscience is so important.”
Lilach Avitan is among 30 Superstars of STEM featured in this weekly series prepared by Science & Technology Australia (STA). To learn more about the program, visit the STA website.