Learned together, extinguished apart: reducing fear to complex stimuli

Freezing to individual components when saliency was matched. (A) Rats were fear conditioned to a single cue (either the 70-dB tone or the blinking light) and then tested to that cue the following day. No significant differences were found in freezing to either the 70-dB tone or the blinking light (t₍₂₅₎ = 0.558, P = 0.582). (B) After compound fear conditioning, long-term memory tests to either the full compound, 70-dB tone alone, or blinking light alone indicated that the rats froze equivalently to the 70-dB tone as to the blinking light (P = 0.464) and that freezing to either of these cues alone was significantly less than freezing to the full compound (P < 0.001).