The Marc Dax (1770–1837)/Paul Broca (1824–1880) controversy over priority in science: Left hemisphere specificity for seat of articulate language and for lesions that cause aphemia

Abstract

One of the most fascinating and frustrating issues in the priority of discovery in science is over just who, for the first time, went on record in the public forum, either orally at a conference or through a published communication, proclaiming that the faculty of articulate human speech was located in the left, not the right, cortical hemisphere. The disputed paper was purportedly written in 1836 by Marc Dax, who died subsequently in 1837. He was a physician in southern France in the city of Montpellier—far from the medical center of Paris. Little note was made of the presumed paper until the early and mid‐1860s, when the issue of language localization in the human brain took on increased activity, as the clinico‐pathological method of explanation continued to flourish in the “Art of Physick.” Marc Dax's son, Gustave, happened to be studying medicine in Paris in the 1860s, and, as most of the neuroscientific and anthropological researchers, came to know of Broca's published work, which in 1861, agreed with phrenological theory that this faculty was, indeed, in the anterior lobes, but further claimed, de novo, that the region in the anterior lobe was more precisely focused at the foot of the 3^rd frontal convolution in that lobe, still assuming with phrenological theory and the “Law of Symmetry” that the faculty was bilaterally located. It was not until 1865 that Broca clearly, non‐hesitatingly, and unambiguously claimed that the faculty was in the left hemisphere. As it turned out, Gustave, six weeks before Broca's paper appeared, had published the paper he said his father had written in 1836. In 1863, in fact, Gustave had submitted his (Gustave's) long monograph on aphemia, integrating what he claimed to be his father's 1836 pronouncement along with his own data. He sent this communication to the French Academy of Sciences and to the French Academy of Medicine; he heard nothing back from either academy. After waiting two years, he managed to publish his material. Gustave's valiant move to promote his father's priority for one of the most significant conclusions in the history of the neurosciences is a lesson in frustration. Broca's attitude towards Gustave's case was disarmingly nonchalant; the issue deserves further historical inquiry.

• Broca's aphasia
• cerebral dominance
• loss of speech
• priority in science
• law of symmetry
• French medicine