No significant activation was observed when contrasting
laugh with the null stimulus, nor was there any significant
activation when contrasting laugh minus yawn. Table 1 and
Fig. 1 depict the significant activations associated with the
yawn minus laugh contrast. This contrast revealed significant
(FDR-corrected P b 0.01) activation in bilateral
posterior cingulate (BA 31) and precuneus (BA 23), and
bilateral thalamus and parahippocampal gyrus (BA 30),
which supports the hypothesis that viewing yawns may
evoke self-referent information. Activation in the posterior
cingulate/precuneus region has been associated with selfreferent
processing and retrieval of autobiographical memories.
Activation in the thalamus and parahippocampal gyrus
may be related to general sensory aspects of face perception.