-9-
GFor example:
åSubject 1 - Signal in hippocampus goes from 1000 (baseline) to 1050     (stimulus condition) 
åDifference = 50 IRF units
å
åSubject 2 - Signal in hippocampus goes from 500 (baseline) to 525     (stimulus condition) 
åDifference = 25 IRF units
å
GConclusion:
åSubject 1 shows twice as much activation in response to the stimulus condition than does Subject 2 --- WRONG!!
å
åIf ANOVA were run on these difference scores, the change in baseline from subject to subject would add variance to the analysis
åWe must control for these differences in baseline across subjects by somehow normalizing the baseline so that a reliable comparison between subjects can be made