In their 2003 Trends in Neurosciences article, Hutsler & Galuske
refer to the well-known history of hemispheric asymmetry
research as too focused on large-scale morphological
differences, at the expense of microanatomical and connectivity
differences. An understanding of these more detailed structural
differences might translate into a more detailed understanding
of hemispheric differences in computation and function. Hutsler
& Galuske identify three levels of structural analysis in
cerebral cortex: the microcolumn, the macrocolumn, and the
functional column. Microcolumns contain vertically-aligned
pyramidal neurons, about 20-50 microns wide, and are sometimes
considered the “smallest processing unit in the cerebral
cortex.” Anatomical macrocolumns can be defined by similarities
in patterns of long-range afferent connectivity, and are usually
200-700 microns wide. Finally, functional macrocolumns are
similar in terms of their receptive field properties – the
stimuli to which neurons in a particular region fir