Range Correction Applied to Heart Rate and to GSR Data.

The utility of the range correction, in which each individual autonomic level or response measure is expressed in terms of estimates of that S's maximum and minimum level or response amplitude, was evaluated in terms of the apparent reduction in error variance indicated by larger or more significant treatment effects. The data analyzed were from an experiment in which 48 Ss received 12 painful shocks in each of four conditions of shock predictability. A reduction in error variance resulted from correcting, for individual differences in tonic range, measures of tonic SC (a replication of previous findings) and measures of tonic HR (a new finding). A reduction in error variance also resulted from dividing each SCR to shock by that S's largest SCR, i.e., by correcting phasic SCR measures for individual differences in range of SCR. No marked improvement resulted from a similar correction of phasic HRR data. [ABSTRACT FROM AUTHOR]