[Figure 3 here]
Figure 3. ERPs at electrode Pz. Shaded area represents P300
peak amplitudes for Happy (top), Angry (bottom left) and Neutral (bottom
right) Faces with ERPs shown for PLC (blue), MA (red) and MDMA (green)
sessions. Neither MDMA nor MA affected the peak amplitude of P300 ERPs.
There was also no effect of Emotion on the P300 response.
MMN – Novelty processing. (Figure 4). MDMA did not
affect MMN amplitude compared to PLC (no interaction between Drug and
Emotion (F(3,129)= 0.91, p>.05 ,
ηp2=0.02) and no main effect of Drug
(F(1,43)= 0.48, p>.05 ,
ηp2=0.01)). MA also did not affect the
MMN peak amplitude (no significant interaction (F(3,129)= 0.51,p>.05 , ηp2=0.01)
and no main effect of Drug (F(1,43)= 0.90, p>.05 ,
ηp2=0.02)). The type of face shown,
however, did affect peak amplitude in PLC and MDMA sessions (F(3,129)=
39.00, p<.001 ,
ηp2=0.48) with Human faces resulting
in a significantly greater MMN than Cartoon faces (all
ps<.001). This was expected because MMN signals
novel/infrequent stimuli. Similarly, in the analysis of MA vs PLC face
type significantly affected MMN amplitude whereas drug type did not
(F(3,129)= 37.14, p<.001 ,
ηp2=0.46) again with Human faces
resulting in a significantly greater MMN than the Cartoon face (all
ps<.001) (Figure 4).