Effects of sequential extinction (or ret+ext) of each component of the compound on LTM. (A) Extinction or ret+ext of the light component followed 3 h later by extinction or ret+ext of the tone component reduced freezing to the T, the L, or the full T+L compound during sequential LTM tests compared to no ext groups, but did not result in significantly different amounts of freezing between ret+ext and ext-only groups. (B) Ret+ext of the tone component followed 3 h later by ret+ext of the light component resulted in significantly reduced freezing compared to both the ext-only and no ext groups during sequential LTM tests performed 24 h after extinction for the T+L and tone components and compared to the no ext group for the T+L, tone, and light components. Error bars represent ± SEM.
