Fig. (2) UCS expectancy and unconditioned SCR. a) Learning-related
differences in UCS expectancy. UCS expectancy on Early
and Late test trials was higher during CS+UCS and CS−UCS trials
vs. UCS alone trials. b) Learning-related changes in unconditioned
SCR expression were also observed. During Early test trials
unconditioned SCRs were diminished on CS+UCS and CS−UCS
trials compared to UCS alone trials. No differences were observed
between CS+UCS and CS−UCS trials. During Late test trials no
differences were observed between CS+UCS, CS−UCS, or UCS
alone trials.