Confusing cortical columns

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Abstract
The late developmental neurobiologist, and a member of the National Academy of Sciences, Victor Hamburger told me during one of our discussions about the distinction between boring data and exciting concepts, “one can spend an entire lifetime correcting a flawed paper published in reputable journal and still loose the battle if people like the basic idea” (V. Hamburger, personal communication). An example of the longevity of basically incorrect information is the phenomenon of “The basic uniformity in structure of the neocortex,” published in 1980 by Rockel, Hiorns, and Powell (1). This highly influential paper had obvious problems at almost every level: The authors selected an arbitrary 30-μm-wide, 25-μm-deep vertical cortical “column” between the pia and the bottom of the cortex, because the ruler in the graticule of the oil-immersion eyepiece on their microscope had a 30-μm marker and their histological sections were 25 μm thick; then, they estimated that the number of neurons within this “minicolumn” is 110 in all cytoarchitectonic areas examined, without any correction for the cell size; and finally, based on this dubious finding, they made a broad generalization that the magic number of 110 is constant in all mammalian species (rodents, carnivore, and primates, including human) in all cytoarchitectonic areas (except the primary visual cortex in primates). This finding led them to conclude that, “the intrinsic structure of the neocortex is basically more uniform than has been thought and that differences in cytoarchitecture and function reflects differences in connections.” Most neuroscientists recognized the problems with both the method used and the data obtained, but many found the simple concept of the uniformity of the cortex across various modalities as well as during evolution of neocortical expansion highly attractive. Although at least six research articles have directly refuted the accuracy of the data of Rockel et al. …