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Unformatted text preview: ething that the brain is doing that is
important for survival. So why is it active when not doing anything at all, but then less active when doing something important? So what is it's function & how is it necessary for our survival? The Default Mode Network of the Brain!
Cognitive Control and the Human Prefrontal Cortex!
“The Architecture of Cognitive Control in
the Human Prefrontal Cortex”!
Koechlin, Ody, & Kouneiher!
Science 2003! focused attention;!
goal-directed behavior! 12:00 The brain regions that were involved in
cognitive control were the lateral PFC regions,
and ACC. A lot of activity of the brain regions
that involved in these sort of tasks tend to be
on the lateral surface, both the dorsal-lateral,
and ventral-lateral cortex, and the ACC. The
DMN is not these-- rather this is the opposite
of it. The Default Mode Network of the Brain! The DMN areas that are involved are the
dMPFC, vMPFC, PCC (wraps around corpus
callosum), IPL, and the hippocampus in the
MTL. These are the 4 regions that make up
this network. medial prefrontal cortex (dMPFC & vMPFC)!
posterior cingulate cortex (PCC)!
inferior parietal lobule (IPL)!
hippocampus & medial temporal lobe (HF+)! Buckner, Andrews-Hanna, & Schacter (2008) The Year in Cognitive Neuroscience ! The Default Mode Network of the Brain!
Functional Connectivity Analysis! The activity within these regions appear to be
synchronized with each other. !
A number of ways to see evidence of the DMN. 1) compare & constract active and passive 2) Scan someone
while not doing anything via PET (fMRI is hard bc need a constrast in order to get a good BOLD signal) 3)
constrast sensitivity (put someone in the scanner w/ no instructions and scan their brain for 5 min. Will get
variable in that BOLD signal, and could think of that as random variation. However it turns out that across this
network of regions, that when you look at two different voxels -- one from MPFC and PCC -- they both have
random variation which occurs in sync. What ever random activity they are going through, they are going through
Functional Connectivity Analysis = measure of how in sync the signals are. Somehow the two different regions
are sychronized and are acting together. The Default Mode Network of the Brain!
& The Progression of Alzheimer’s Disease ! The DMN is important for alot of
disease states as well. Several
disease states or disorders that
are related to atrophy w/i the
If you look at a normal aging
brain, you get activity in the PCC
and medial PFC, but in someone
w/ Alzheimer's Disease, see no
activity in the PCC, and reduce
activity in the mPFC.
If you try to map the building of
plaques in AD, and the
progression as the plaque
progress, you see the initial
buildup is in the DMN
(blue areas show less activity
when not doing a task.. and AD
has more activity when not doing
Also true for other disorders, like
for Schizo and Psychopaths.. no
difference in activation in the...
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This note was uploaded on 01/18/2014 for the course PSY 123 taught by Professor Staff during the Fall '11 term at UCSB.
- Fall '11