From Medical Xpress:
Researchers from EPFL and UNIL have used flies to show how behaviors may be shaped by seemingly random brain activity. This study raises new questions about the role of neural noise in moment-to-moment decisions.
What processes lie behind voluntary actions like when to walk or rest? According to a study carried out by EPFL and the University of Lausanne, these choices may be shaped in part by neural fluctuations. Neurons in the brain are never quiet. They are constantly producing and receiving signals – like background noise – yet the influences of these signals on behavior remain largely mysterious.
The researchers studied the fruit fly, Drosophila melanogaster – a popular experimental animal model – to determine the impact of noisy neural fluctuations on the timing of flies’ walking behaviors. They recorded the behaviors of thousands of flies and tested if it was possible to mimic their largely unpredictable walking patterns using a computer simulation of networks of artificial neurons driven by random fluctuations.
Their study showed that fluctuating neural signals were indeed required to reproduce fruit fly behaviors. Most surprisingly, by looking closely at these neural networks, they found that these signals did not simply disrupt neural activity, but could actually sculpt behavior in a meaningful way. “Our models predict that these fluctuations affect the relationship between what a fly senses and how it reacts,” said researcher Pavan Ramdya. “With noise, otherwise weak sensory signals may have a surprisingly strong influence on walking behaviors.”