Welcome!

I am a French neuroscientist specialized in sleep and dreaming.

I obtained my PhD from the University of Lyon in December 2017. My doctoral project was conducted with Dr. Perrine Ruby and aimed at understanding the neurophysiological basis of dream recall (i.e. how and why we sometimes recall our dreams and sometimes forget them). I am currently working as a postdoctoral researcher in Pr. Matthew Walker's lab at the University of California, Berkeley. My project aims at studying the impact of sleep deprivation on brain function and (social) decision-making.

I also have a strong interest in statistics, machine-learning and signal processing. I am the (co)-founder of several open-source Python packages that are currently under active development: Pingouin (statistics), Visbrain (sleep staging), YASA (sleep microstructure analysis) and EntroPy (signal processing).

News

Introducing YASA: Yet Another Spindle Algorithm

January 2019

I have been recently trying to create a robust, fast, and data-agnostic sleep spindle detection algorithm. The result is named YASA (Yet Another Spindle Algorithm) and you can find it on GitHub. The algorithm behind YASA is a fast (and hopefully smart) implementation of the method described in Lacourse et al (2018).

PhD thesis online

October 2018

I have decided to upload the full PDF (and LaTeX files) of my PhD thesis. It's a long read but (hopefully) an up-to-date review of what we - sleep and dream scientists - know and do not know about dreaming. In short, the goal of this thesis is to give some elements of answer to a question asked by Aristotle more than two thousand years ago:

We must also inquire what the dream is, and from what cause sleepers sometimes dream, and sometimes do not; or whether the truth is that sleepers always dream but do not always remember (their dream); and if this occurs, what its explanation is.
— Aristotle. On Sleep and Sleeplessness. 350 B.C.

The cerebral correlates of sleep inertia

September 2018

I am thrilled to announce that our article on sleep inertia is published in NeuroImage.

Ever felt groggy, sleepy, and disoriented when awakening from a long mid-afternoon nap?

In this article, we have investigated this phenomenom, called "sleep inertia", using a combination of behavioral tasks, resting-state fMRI scans and continuous EEG. We have measured the brain function of 34 participants before an afternoon nap, 5 minutes straight after awakening and 25 minutes after. Our results show that sleep-specific brain activity does not disappear immediately after we wake up but instead persists for several minutes, as illustrated by decreased cognitive performance, increased EEG delta power and disruption of brain functional networks (the two latter being typically observed during sleep). In addition, we have found that this sleep inertia progressively dissipates across the first half hour after awakening and that its severity and duration is related to the depth of sleep prior to awakening.

Pingouin: a statistical package in Python

April 2018

I am very happy to introduce my new open-source Python package, called Pingouin. Pingouin is born out of a personal need to reduce and simplify the number of steps in my statistical analyses. Pingouin provides simple and easy-to-grasp statistical functions for computing ANOVA, post-hoc tests, robust correlations, Bayes factors and effect sizes. Pingouin is based on Pandas and therefore allows to leverage the power of this latter. Learn more on the documentation or check the code on GitHub.

Post doctoral position at U.C Berkeley

November 2017

I am thrilled to announce that I will join Pr. Matthew Walker at U.C Berkeley (USA) for a two-years post-doctoral position starting February 2018.

New papers out

October 2017

Academics

Link to my full curriculum vitae (pdf format - last updated September 2018)

  • Education

2018-Present Postdoctoral fellow, Walker lab, U.C. Berkeley
2014-17 PhD in Neuroscience, with honors, Lyon 1 University
2012-14 Master degree in Neuroscience, cum laude, Lyon 1 University
2009-12 Bachelor degree of Cognitive Sciences, summa cum laude (ranked 1st), Lyon 2 University

  • Expertise

Methods Polysomnography, sleep studies, actigraphy, combined EEG-fMRI, resting-state and task-based fMRI, behavioural studies, circadian rhythm
Analysis Sleep scoring, EEG signal processing, functional and connectivity MRI analyses, machine-learning, dream content analysis
Programming Python, Matlab, SPM, CONN Toolbox, FSL, HTML, LateX, Shell, R, PsychoPy

  • Teaching

Neurobiology / Neuroanatomy, 1st and 2nd year of Bachelor Degree in Biology (145h)
Social science, 1st year of Medicine (50h)
Neuro-imaging (fMRI analysis), Neuroscience Master degree (~10h)

Publications

Please find below a list of publications (last updated October 2019)
PDF versions are provided for individual, noncommercial purposes only. These files may not be reposted without permission. Copyright and all rights therein resides with the respective copyright holders, as stated within each paper.

Media outreach

General sleep science

Sleep inertia study

Vallat et al., NeuroImage, 2018

Software development

Please visit my GitHub repository for an exhaustive list of the projects/softwares that I am contributing to.

Visbrain | SLEEP

The SLEEP module of the Visbrain package is an open-source software for visualization and analysis of sleep polysomnographic data. Learn more on the documentation or read the peer-reviewed publication.

YASA

YASA (Yet Another Spindle Algorithm) is an open-source Python package dedicated to sleep (microstructure) analysis. Among others, it implements several state-of-the-art and validated algorithms to detect spindles, slow-waves, and rapid eye movements. Learn more on the documentation or check the code on GitHub

SleepViz

SleepViz is the (deprecated) MATLAB prototype of SLEEP. Click here for a quick start guide.

Guides

Please find below some tutorials regarding the analyses I specialize in.

EEG bandpower

Compute the average bandpower of an EEG signal in Python.