While age effects in reaction time (RT) tasks across the lifespan are well established for level of performance, analogous findings have started appearing also for indicators of intra-individual variability (IIV). Children are not only slower, but also display more variability than younger adults in RT. Yet, little is known about potential…

Discusses normative developmental changes in cardiovascular and electrodermal activity and describes the dynamic balance between branches of the autonomic nervous system. Issues for further developmental study are identified, and problems and limitations in the psychophysiological study of children are explored. (Author/RH)