What is where and why it is important

The paper by Devlin and Poldrack entitled ‘In praise of Tedious Anatomy’ deals with an increasingly important topic. Namely, how do we effectively communicate, with appropriate accuracy and precision, the ‘where’ of our measurements? They make cogent arguments for the use of anatomical maps to reference the location of functionally active regions of brain as measured with fMRI. We agree with this premise and would like to amplify further (with some additional suggestions) the rationale for equating functional measures with observations about structure. But before we do that, it might be useful to first generalize this issue, as one that pertains to 1) comparing data collected across multiple subjects, modalities, experiments and laboratories and 2) integrating this data as a comprehensive whole. Specifying the site of activation, in anatomic terms, is intended (in part) to provide the ability to compare and contrast different studies. The notion of an atlas is, among other things, to help with this localization. Unfortunately many anatomic terms are sometimes interpreted variably and the boundaries of anatomic regions are sometimes in dispute. Given the mostly descriptive history of anatomy, its application, in a traditional sense, to modern volumetric MRI surveys of the brain sometimes produces more problems than it solves. Atlases such as the (Talairach and Tournoux, 1988) are woefully inadequate as an anatomic reference but did encourage the use and further development of spatial normalization schemes to reduce size and shape variability of brains. Other atlases such as (Ono et al., 1990) and (Duvernoy, 1991, Schleicher et al., 2005) provide far more complete and detailed delineations but either do not provide any principles or algorithms for spatial normalization or Cartesian coordinate systems. And finally, the question of how a single brain based atlas can represent a population is rarely argued anymore.