[Roland]: There's a lot that we don't know about the nature of those experiences.
There's a little bit known about the immediate effects of psilocybin.
Certainly, we know that psilocybin binds serotonin 2A.
We know different areas of brains that are activated and deactivated.
We know something about the default mode network.
[Rhonda]: I wanted to ask you about that.
It's very interesting.
[Roland]: Yeah.
And so work from the UK and additional work now is showing that at least acutely, psilocybin
appears to decrease activity within the default mode network.
[Rhonda]: So from my understanding, because I don't know much about this and this is all
from neuroimaging studies you're talking about which I'm sourced in.
The default mode network, is that something that's active like when you're ruminating
on something, like when you're thinking about something that you...?
So rumination which is associated with depression, and ruminating on the future or the past or...
[Roland]: Exactly.
[Rhonda]: That's it, right?
[Roland]: Yeah, that's it.
And so activity in the default mode network is actually increased in depression, and here,
a couple of the hubs are prefrontal cortex and posterior cingulate.
And the connectivity and activity in those regions are decreased.
Now, the interesting thing about the default mode network is it is associated with rumination.
It's sometimes thought to be responsible for what's called self-referential processing
as...
[Rhonda]: What's that?
[Roland]: Ideas that relate to a sense of self, and that's kind of what rumination is.
Woe is me...yeah.
So that's increased in depression, and interestingly, activity in the default mode network is decreased
in long-term meditators.
[Rhonda]: Oh, that's interesting.
[Roland]: Yes, yeah.
And that fits, if you think about it, with this whole story about goals of meditation
being to bring you into the present moment, to drop the ego, to surrender a sense of self,
if you will.
So the curious thing now is that psilocybin looks very much like meditation in that regard.
So that decreases in the default mode network, and that kind of fits with this story we can
tell in terms of the phenomenology that one thing that people are encouraged to do when
they have this experience is surrender a sense of egoic holding.
That is kind of get out of the way of the experience and just be present in the present
moment, and that's the thing that I...one of the qualities of that experience where
you get out of past and future and your present and you're present in a way that it untangles
you from this hell sense of self and constraining.
But these, of course, are all kind of words we don't have their descriptive ways
of putting a framework around psychological processes, but they fall short of kind of
the empirical hard science that we would like to have.
So it's kind of frustrating.
We're dealing a lot in metaphor at this point in terms of descriptive framework for how
these experiences might affect people.