LSD’s [increased blood flow and connectivity profile] on the visual cortex did not significantly correlate with the drug’s other characteristic effects on consciousness, however. Rather,
decreased connectivity between the parahippocampus and retrosplenial cortex (RSC) correlated strongly with ratings of “ego-dissolution” and “altered meaning,” implying the importance of this particular circuit for the maintenance of “self” or “ego” and its processing of “meaning.”
Significant relationships were found between ego-dissolution and decreased delta (mean cluster, r = −0.54; P < 0.05) and alpha power (mean cluster, r = −0.29; P < 0.05) and between simple hallucinations and decreased alpha power (mean cluster, r = −0.61; P < 0.05) (Fig. 4

. Plotting the power spectrum independently for each condition for the significant alpha cluster (Fig. 5C), i
t is evident that the distribution of power is decreased across a broad frequency range under LSD