They met in 1986 in the laboratory of Jacques Mehler, a pioneer of cognitive science in France. Ghislaine was studying the linguistic understanding of newborns, while Stanislas was investigating how adults represent numbers, and the role that language acquisition and symbols play in our mathematical abilities. “We haven’t been apart since, and continue to collaborate thirty years later…but we quickly decided on a healthy division of work.” She tackles the baby brain, with its inherent capabilities and fabulous learning abilities, while he focuses on the adult brain and the way in which it reorganizes itself according to how it is educated.
The strange apparatus they are wearing on their heads is a “geodesic sensor net with 256 electrodes.” It records the electro-encephalogram (EEG), the brain’s electrical activity, with high spatial and temporal resolution. Ghislaine was the first to use this tool with infants. “In 1994, we made the cover of Nature with a magnificent two-month-old smiling baby, wearing the net, whose recorded brain waves illustrated the complexity of the steps involved in processing spoken language. We still use this machine to study cerebral responses in babies, but also to visualize the adult brain, and markers of consciousness in particular.
We also use magnetoencephalography (MEG), which records the ultra-weak magnetic signals emitted by neurons. With it, we are able to follow the temporal unfolding of information processing with unparalleled sensitivity. It takes about 170 milliseconds to read a word and about a third of a second for it to reach the consciousness. Our consciousness, then, lags constantly behind reality. We also use functional magnetic resonance imaging (fMRI), which allows for remarkable spatial precision. With it, we can see right down to the millimeter and are able to decode the intertwining of representations at the surface of the cortex, and have demonstrated a remarkable dissociation between language and mathematics: these cognitive functions activate distinctly different regions of the cortex, and simply reading a number or a letter calls upon specialized areas of the visual cortex.” Ghislaine was the first to show that fMRI could be used in babies, and that large cortical language networks, including the Broca area, are activated from the age of two months.
“Our next challenge? Understand the human species’s singularity in the animal kingdom. Why are we the only species to create language, music and symbols?” Ghislaine will also study how the baby brain manages very early on to learn words and invent symbol systems. Stanislas will analyze the neural codes that allow several symbols to be combined to form a sentence. “Are symbols and syntax unique to humankind? How do they get into our heads? We’d like another thirty years to shed a little light on the subject!”
Ghislaine Dehaene is Research Director at CNRS and received the Grand Prix de la Recherche from the Fondation de France in 2015. Stanislas Dehaene is a Professor at the Collège de France and received the Grand Prix Inserm in 2013.
Ghislaine Dehaene-Lambertz, pediatrician and research director, proposes, through a project entitled BabyLearn, to study the neural mechanisms of learning in the brain of the infant, from the fetal stage up to one year of life. Stanislas Dehaene, research director and professor at the Collège de France, is receiving ERC funding for a project entitled NeuroSyntax, which aims to study the specific brain depiction of the human being. These two ERC projects, each financed by € 2.5 million each, will take place from 2016 to 2021.