Decoding behaviour: an interview with Fanny Cazettes

The physicist Richard Feynman once said: “So what is this mind of ours: what are these atoms with consciousness? Last week's potatoes!” To me it is astonishing that the brain, an organ made of the same atoms that make up everything else in the world, possesses such inner faculties. How does this highly organized structure give rise to perception, decision-making and emotions?

To catch their interest I tell them that our perceptions are an illusion. Everything we sense is interpreted by the brain, which creates its own representations of the world. In our research my colleagues and I are trying to uncover the language of neurons – the neural code – to understand these representations and how they support behaviour. We investigate these questions in barn owls, which offer advantages for understanding the neural code and how sound is processed and interpreted.

The owl is an auditory specialist that orients its head towards sound in a very characteristic and precise manner that is easy to assess. In addition, three decades ago neuroscientists discovered a map of space in the owl's brain and the neural processing underlying its emergence. Therefore, owls are good models for studying the neural code that supports how vertebrates behave in response to a sensory stimulus.

When prey emits a sound, the owl tracks the direction of the sound from the information reaching its ears. We have investigated the degree to which this auditory information could be trusted in different contexts: in other words, are the auditory cues received by the owl reliable or not? We found that for each direction, only a certain range of the frequencies in the sound carries reliable information. We then discovered that the neurons that represent space in the owl's brain were only sensitive to this range of frequencies (Cazettes et al., 2014).

Discovering that neurons select the information that is most reliable challenges the traditional view of sensory neurons. In the auditory system, these neurons are not just sensitive to the properties of the sounds they are exposed to; they also dictate what information can be relied upon. To our knowledge, this is the first demonstration that sensory neurons are tuned to the information that can be most trusted.

The results reported in our eLife paper have led us to explore two new questions: how are ongoing changes in the reliability of the auditory cues captured? And how is this reliability incorporated into the neural code to make the best decisions?

I feel fortunate enough to have had several good moments in the lab. The last one I remember was discovering that the response of some neurons in the owl's brain resembled neurons in the mammalian brain, even though they are normally viewed as using different coding strategies. Although very preliminary, these results could lead us to define general principles of how neural computations are used to locate the source of a sound. This is very exciting!

Life in the lab is as rewarding as it is frustrating. Moments of desperation can happen when results vanish after correcting a bug in the code. I think this is a reality that everybody writing code has experienced. However, it has taught me to be more careful and rigorous.

Thanks to Antonio Convit, who offered me a job at NYU, I had the opportunity to enter the world of neuroscience research. I have met many inspiring people at Einstein but my PhD advisor, Jose Luis Pena, is undoubtedly the person who has most influenced how I approach research. I have learnt from him to always be critical and, more importantly, to try to be original in my thinking. He also taught me not to take all his words for granted but to think for myself.

I think that encouraging more interdisciplinary collaborations could be very beneficial. In the field of systems neuroscience, when biologists, mathematicians, physicists, engineers and even artists work together it results in innovative ideas and elegant ways to test them.

Witnessing the struggle of principal investigators because of the worsening economic climate for basic science is not encouraging for young scientists who wish to pursue a research career. It may seem like a trivial answer but allocating more funding for, and recognizing the importance, of fundamental research would also give early career scientists confidence in the future.

I am a dance fitness enthusiast! During my spare time I also enjoy the arts and culture that my cities, today New York and previously Paris, have to offer. Keeping my traditions from southern France alive, I also appreciate good food paired with fine wine.

Most of the time, no. However, I do wonder how I would manage my time if I decide to have a family one day.

Yes, he is a neuroscientist too. He is now a postdoctoral fellow at Einstein, and we work in the same department. We met at a restaurant in Manhattan before either of us was at Einstein. We often discuss science and can understand each other's professional life.

My long-term goal is to pursue an academic career in systems neuroscience. I hope that ten years from now I would have achieved this goal.

I am a mother of three... barn owls! For a behavioural project in my lab, I have hand-raised and trained these baby owls. They now sit next to me every day in the office, and they let no one handle them but me. I named my owls Laplace, Fourier and Poisson after three great French mathematicians whose work set the foundation of our project.

• 2011–present: PhD student in Neuroscience, Albert Einstein School of Medicine, Bronx, USA
• 2010–2011: Research assistant at the BODyLab, NYU, New York City, USA
• 2007–2010: MS in Bioscience Engineering, ISBS, Paris, France
• 2005–2007: CPGE in Biology and Physics, Toulouse, France