follow-up (posthoc) analyses from an LMER model

Hi everyone,
I'm wondering how to do follow-ups for an LMER model (e.g., Y ~ A * B
+ (1|Subject) + (1|Item) )

If you fit a model using the function aov(), naturally without the
random effects terms, you can use the TukeyHDS() function to do
multiple comparisons or the pairwise.t.test() function. Unfortunately,
these two functions can't be used to do posthocs analyses from an LMER
model (at least to the extent of my knowledge).

Thanks for your time!

Antoine

Antoine Tremblay
Department of Neuroscience
Georgetown University
Washington DC