 Over the last three decades, new evidence for localizations of cognitive functions has come increasingly from a new source, the development and refinement of neuroimaging techniques. However, the logical form of localization-of-function arguments appears not to have changed from those employing lesion studies, as analyzed by Von Eckardt Klein. Instead, these new neuroimaging technologies resolve some of the methodological problems that plagued lesion studies. For example, researchers do not need to wait until the patient dies, and in the meantime probably acquires additional brain damage, to find the lesion sites. Two functional imaging techniques have been prominent in philosophical discussions: positron emission tomography, or PET, and functional magnetic resonance imaging, or fMRI. Although these measure different biological markers of functional activity, PET approved for human use now has spatial resolution down to the single mm range, while fMRI has resolution down to less than  1mm.[15]  As these techniques increased spatial and temporal resolution of functional markers, and continued to be used with sophisticated behavioral methodologies, arguments for localizing specific psychological functions to increasingly specific neural regions continued to grow. Stufflebeam and Bechtel provided an early and philosophically useful discussion of PET. Bechtel and Richardson (1993) provided a general framework for “localization and decomposition” arguments, which anticipated in many ways the coming “new mechanistic” perspective in philosophy of science and philosophy of neuroscience (see  sections 7 and 8 below).  Bechtel and Mundale (1999) further refined philosophical arguments for localization of function specific to neuroscience.