Psy 123_Lec 16 Social Cognition

So why is it active when not doing anything at all

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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;! cognitively engaged;! 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 it together. 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 DMN. 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 a task) 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.

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