Fig. 1.

Experimental overview for fear conditioning and test sessions. A = Rats were conditioned on Day 1 in Context A or B in either a delay, trace, or unpaired paradigm. They received a 10-min Context Recall on Day 2 where they were returned to their Day 1 context for 10 min. On Day 3, rats were placed into a novel context and presented with the auditory cue during a Cue Recall session. B = Two contexts were used to distinguish the behavioral reactions to the context and auditory cue. Context A was a darkened conditioning chamber (houselight off) with a lavender scent, whereas Context B was a lit chamber (houselight on) with a starred background wallpaper and sawdust. C = Delay, trace, and unpaired conditioning schematic. In delay conditioning, the auditory CS co-terminates with the US. In trace conditioning however, the US is presented 30 s after the termination of the CS. In unpaired conditioning, the CS and US were explicitly unpaired.