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. Author manuscript; available in PMC: 2009 Sep 14.
Published in final edited form as: Learn Behav. 2009 Aug;37(3):254–268. doi: 10.3758/LB.37.3.254

Table 2. Design summary of Experiment 2.

Group Conditioning Extinction Test Pred ECH Pred Biol Significance
NoExt 5 AX → US (8) Short Ctx (20 min) X cr cr
NoExt 125 AX → US (8) Short Ctx (20 min) X CR CR
ExtA+C 5 AX → US (8) A- (200) in long ctx (8 h) X CR CR
ExtA+C 125 AX → US (8) A- (200) in long ctx (8 h) X CR CR
ExtC 5 AX → US (8) Long Ctx (8 h) X cr cr
ExtC 125 AX → US (8) Long Ctx (8 h) X cr CR

Note: NoExt = No extinction treatment, ExtA+C = Extinction of A and the context, ExtC = Extinction of the context, 5 and 125 = 5-s and 125-s CS duration, A (tone) = overshadowing stimulus, X (clicks) = target cue, US = footshock. Numbers in parentheses refer to the number of each trial type or duration of context exposure. Pred ECH = predictions of the extended comparator hypothesis (Denniston et al., 2001). Pred Biol Significance = predictions based on the principle of biological significance (Miller & Matute, 1996). CR and cr denote strong and weak stimulus control, respectively.