Mental chronometry in the study of individual and group differences

The papers in this issue are excellent examples of the many uses of measuring reaction time in the exploration of nervous system pathologies. In our commentary we consider mental chronometry as a field that seeks to measure the time course of mental operations in the human nervous system. We draw upon diverse methods such as neuroimaging, electrical recording and reaction time to illustrate the use of chronometry in conjunction with anatomy and genetics to approach both normal individual differences and pathologies. The goal is to examine general and specific changes in neural networks that underlie both variations in normal function and changes due to pathology. Although much remains to be done along these lines, it is now possible to see how the various chronometric contributions outlined in this special issue can converge to provide a basis for improved understanding of the genetic and experiential basis of cognitive and emotional processes.