Table 1.

Experimental design

Phase 1: preexposurePhase 2: unpairedPhase 3: CS1 pairedPhase 4: cross-modalPhase 5: CS1/CS2 paired
ToneTone−CS1+CS2+CS1+
LightLight−CS2+
+
  • Design summary: Tone, 500 ms, 2 kHz CS; Light, 500 ms, 1.25 W CS; +, a 25 ms US was presented; −, no US. CS1 and CS2 were the tone and light CSs (counterbalanced).