SISSA Cognitive Neuroscience professor Jacques Mehler passed away in Paris on February 11 at the age of 83. Jacques Mehler was a key figure of the cognitive revolution in psychology in the 1960s and conducted foundational research on human cognition, in particular on language acquisition, ever since. He was a pioneer in studying infant cognition. He participated in showing that neonates are not blank slates that need to be written on by experience. Rather, they are equipped with specialized learning mechanisms, particularly with regard to language acquisition, which start functioning very early on. This view, quite iconoclast in the 70s and 80s, was summed up in his 1994 book Naitre Humain/What infants know, and has inspired many researchers around the world, particularly the students who had the privilege to have him as a mentor.
Jacques showed that the syllable plays a key role in newborns’ representation of speech; furthermore, newborns recognize their mother tongue and can discriminate languages, even those never heard before, on the basis of their rhythmic properties. He also pioneered and perfected several methods for newborn testing, including high amplitude (or non-nutritive) sucking, the most commonly used behavioral method with newborns, and more recently near-infrared spectroscopy, a non-invasive brain imaging method, which has revolutionized developmental cognitive neuroscience. Using this method, Jacques showed that neonates already exhibit a left hemisphere advantage for the processing of their native language, similarly to most right-handed adults, and they are able to learn simple linguistic regularities and have a speech-specific memory for word forms.
He also showed a continuing interest in bilingualism, showing that even the most balanced bilingual adults have a dominant language. He showed that infants reared with two languages from birth later show enhanced abilities of cognitive control, related to their constant monitoring and managing of two languages simultaneously.
His research also extended to numerical cognition and mathematical abilities. He showed that the human number sense can be decomposed into three sub-systems, two of which, the immediate recognition of small numerosities known as subitizing and the approximate recognition of magnitude known as magnitude estimation, are shared with other animals, while the mental representation and manipulation of exact qualities and numbers is uniquely human and relies on language.
In addition to his scientific discoveries, Jacques Mehler was also the founder and editor for 30 years of the high-impact journal Cognition, one of the most broadly read and influential outlets for research in cognitive neuroscience.
After his studies in Argentina and the UK and a PhD from Harvard University, Jacques moved to Europe, engaging in a ground-breaking debate on human development with Jean Piaget at the University of Geneva. He then established his laboratory in Paris, where he worked for three decades, producing some of his most foundational discoveries on newborn infants’ speech perception abilities, language acquisition, bilingualism, and mathematical cognition. In 2001, he moved to SISSA and, together with co-director Marina Nespor, built up a new laboratory, attracting students from all over Europe, North and South America. With this group, he produced more than a hundred articles, among them a dozen papers in the highest-impact journals (Science, PNAS etc.), numerous book chapters and other contributions. At SISSA he conducted his pioneering work in developmental cognitive neuroscience using near-infrared spectroscopy, he continued his work on bilingualism, showing that the bilingual advantage was prelinguistic and identified many key mechanisms underlying speech processing and language acquisition. While at SISSA, he employed summer schools to help create a support network for young investigators in cognitive science from his native Argentina and South America more broadly.
He retired from SISSA in 2016.
His legacy lives on in the cognitive science community, especially among his many intellectual children, who think of him not only as a mentor, but also a role model and a friend.
Jacques Mehler’s former mentee at SISSA