p548fig15.17 The timing paradox asks how inhibition of an orienting response (-) can be spread throughout the ISI, yet accurately timed responding can be excited (+) at the end of the ISI.<BR>||  Timing paradox.  [CS light, US shock] vs t.  ISI = InterStimulus Interval = expected delay of reinforcer.  Want timing to be accurate.  Want to inhibit exploratory behaviour throught ISI.