The history of cerebral localization is the focus of the most recent issue of the Journal of the History of Neurosciences. An outgrowth of a World Federation of Neurology Research Group on the History of the Neurosciences Fall 2005 symposium, the issue explores the history of cerebral localization from antiquity up to the twentieth century.
Articles in this issue include:
“Cerebral Localization in Antiquity” by F. Clifford Rose
“Cerebral Localization in the Eighteenth Century – An Overview” by Axel Karenberg, Institute for the History of Medicine and Medical Ethics, University of Cologne, Cologne, Germany
“Cerebral Localization in the Nineteenth Century — The Birth of a Science and its Modern Consequences” by David A. Steinberg, Fiddletown Institute, Fiddletown, CA
“The Role of Focal Epilepsy in the Development of Jacksonian Localization” by M. J. Eadie, Department of Medicine, University of Queensland, Brisbane, Australia
“Localization of Language Function in the Twentieth Century” by George K. York III, Fiddletown Institute, Fiddletown, CA
Also in this issue of the Journal of the History of Neurosciences, is an article previously blogged about at AHP: “Face to Face with Phineas Gage” by Photographic Collectors Jack and Beverly Wilgus. The article features the first known photograph of railway accident survivor Phineas Gage.
The cytoarchitectonic subdivisions of both the thalamus and the neocortex are topographically defined in terms of the variables of phylogenetic age and input specificity. The cortical and thalamic parcellations of Brodmann, von Economo and Hassler are each quantitatively correlated to a specific Cartesian coordinate value designating discrete levels for both age and input basic parameters. The variable of phylogenetic age is represented in the cortex by the five circumferential growth rings demonstrated by Sanides, plus an additional growth ring detected intermediate to the fifth and sixth age levels and designated as “prekoniocortex.” The paleocortex and the archaecortex are the two primordial neocortical precursors that form the mammalian neocortex. In contrast to the arrangement in the planar cortex, six phylogenetically distinct “growth shells” are detected in the three-dimensional thalamus and are designated after the corresponding schematic levels of Rolf Hassler’s paradigm of hexapartition of unit-thalamic inputs. The subthalamus and the epithalamus analogously represent the primordial diencephalic precursors of the mammalian dorsal thalamus, Both the neocortex and the dorsal thalamus evolved in response to the necessity for a more comprehensive blending of inputs from differing neuraxial levels. Unlike the age variable, the parameter of input specificity is most readily apparent in the dorsal thalamus; which is the site of termination for each major forebrain input. Accordingly, the fourteen individual units of the parameter of input specificity are designated after each of the specific input classifications projecting discretely to circumscribed thalamic sectors, An identical complement of input parameter levels also occurs in the cortex by way of thalamic relay across the internal capsule. Furthermore, each thalamic nucleus of specific parameter coordinates directs its main projection to cells of the cortex displaying identical coordinate values, establishing forebrain interconnectivity as an additional function of the dual parameter paradigm. more at forebrain.org