Appendix Six
Research
Update
David Center
In the section on
the brain and meditation, I discussed what in neuroscience is called
the "default mode network." In that section, I relabeled
the default network as the "relaxed attention network" (RAN)
and the alternate state as the "focused attention network"
(FAN). Below are excerpts from that section that review my hypothesis
about the function of the "default network" or "relaxed
attention network (RAN)."
"When
RAN is engaged, what you get appears similar to free association or
random presentation. In this state, thoughts, memories, images and
feelings stream into awareness often with little or no apparent
structure. As long as these stimuli stream, you remain in RAN.
However, if you focus on one or more of these stimuli and begin to
engage with it, FAN comes back into operation. Thus, FAN can be
focused on either an external or an internal task. To illustrate the
process of going from RAN to an internal version of FAN, think of
standing in front of a conveyor belt and watching suitcases streaming
by. This is analogous to RAN-generated thoughts and images streaming
through awareness. If you grab one of these suitcases off of the
conveyor belt and begin unpacking it, this is analogous to focusing
on one thought or image and following a chain of associations
elicited by your attention to it. You are now back in FAN. This,
however, is usually a less engaged level of FAN than the level, for
example, required for solving quadratic equations or teaching someone
to read. This suggests that there are degrees of FAN and RAN, meaning
that they are not "digital" states that are either on or
off.
"My
introspective observation is that RAN is largely responsible for
the creation of a fictive-self, self-narrative or ego and especially
for maintaining and reinforcing it [emphasis added]. One way of
thinking about the ego is as a psychological construct that functions
as the subject or "doer" assigned responsibility for our
activities. This fictive-self begins forming early in the
developmental period and generally becomes stronger as a child ages
into an adult. It seems to me, again from introspective observation,
that most of the activity generated by RAN is to bring into awareness
thoughts, images and memories associated with our experiences. These
become the "bricks" from which we build, repair and
reinforce our fictive-self."
Now,
a recent study discussed in the New Scientist has provided
evidence that supports my hypothesis:
"The
team gave 20 volunteers infusions on two days, once containing 75
micrograms of LSD, the other [day] a placebo. Then volunteers lay in a
scanner and had their brains imaged with three different techniques,
which together built up a comprehensive picture of neural activity,
both with the drug and without.
Carhart-Harris et al.
MRI scans showed that LSD
caused brain activity to become less coordinated in regions that make
up what is called the default mode network. The size of the effect
was correlated with participants’ ratings of their own ego
dissolution, suggesting that this network underlies a stable sense
of self [my emphasis]."
Another imaging type,
magnetoencephalography (MEG), showed that the rhythm of alpha
brainwaves weakened under LSD, an effect that was also correlated
with ego dissolution. Alpha rhythms are stronger in humans than other
animals, and Carhart-Harris thinks it could be a signature of
high-level human consciousness.
https://www.newscientist.com/article/2083851-first-lsd-brain-imaging-study-offers-insights-into-consciousness/?cmpid=NLC|NSNS|2016-1404-newGLOBAL&utm_medium=NLC&utm_source=NSNS
http://www.pnas.org/content/early/2016/04/05/1518377113
Note:
There is evidence that a reduction in alpha wave activity and a
significant increase in gamma wave activity occurs in the brains of
highly experienced meditators. Further, there are also some
observations that suggest the possibility that high levels of gamma
activity might be associated with suppression of the "default
mode network" or RAN. See "Gamma Waves and Advanced
Meditators" (see Appendix 2).