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This article addresses the discrepancy between Edouard Hitzig's and David Ferrier's findings on the cortical localization of movements in animals and Jean-Martin Charcot's findings in humans. The results of Hitzig's and Ferrier's vivisections were criticized by experimentalists in England and France as discordant, irreproducible, and inconclusive, and they were rejected by clinicians as irrelevant. Charcot addressed the gap between animal and human motor function by correlating motor deficits and focal epileptic seizures in patients to their autopsy findings. By this method he discovered the functional organization of the human motor cortex and produced the first accurate human motor brain map. Ferrier, William Osler, and Hughlings Jackson acknowledged Charcot's findings, and his findings guided the first neurosurgeons in localizing and resecting intracranial mass lesions presenting with focal epileptic seizures. Although his contributions in these fields have been neglected by modern historians, Charcot made significant contributions to the neurobiology of the human motor system, to epileptology, and to the birth of modern neurosurgery.

The idea that the brain is a representational organ has roots in the nineteenth century, when neurologists began drawing conclusions about what the brain represents from clinical and experimental studies. One of the earliest controversies surrounding representation in the brain was the "muscles versus movements" debate, which concerned whether the motor cortex represents complex movements or rather fractional components of movement. Prominent thinkers weighed in on each side: neurologists John Hughlings Jackson and F.M.R. Walshe in favor of complex movements, neurophysiologist Charles Sherrington and neurosurgeon Wilder Penfield in favor of movement components. This essay examines these and other brain scientists' evolving notions of representation during the first eighty years of the muscles versus movements debate (c. 1873-1954). Although participants agreed about many of the superficial features of representation, their inferences reveal deep-seated disagreements about its inferential role. Divergent epistemological commitments stoked conflicting conceptions of what representational attributions imply and what evidence supports them., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

This article is an outline of the transition in "brain maps" used to illustrate locations of cortical "centers" associated with movements, sensations, and language beginning with images from Gall and Spurzheim in the nineteenth century through those of functional magnetic resonance imaging in the twenty-first century. During the intervening years, new approaches required new brain maps to illustrate them, and brain maps helped to objectify and naturalize mental processes. One approach, electrical stimulation of the cerebral cortex-exemplified by Fritsch and Hitzig in 1870, Ferrier in 1873, and Penfield by 1937-required brain maps showing functional centers with expanded and overlapping boundaries. In another approach, brain maps that linked cortical centers to account for the complex syndromes of aphasia, apraxia, alexia, and agraphia were initially constructed by Baginsky in 1871, Wernicke in 1874, and Lichtheim in 1885, then later by Lissauer in 1890, Dejerine in 1892, and Liepmann in 1920, and eventually by Geschwind in 1965 and others through the late twentieth century. Over that intervening time, brain maps changed from illustrations of points on the cerebral cortex where movements and sensations were elicited to illustrations of areas (centers) associated with recognizable functions to illustrations of connections between those areas that account for complex symptoms occurring in clinical patients. By the end of this period, advancements in physics, mathematics, and cognitive science resulted in inventions that allowed brain maps of cortical locations derived from cognitive manipulations rather than from the usual electrical or ablative manipulations. "Mental" dependent variables became "cognitive" independent variables.