Naming convention of the DMN lateral regions

Hi,

There are two well-known lateral posterior-temporal regions (red and yellow arrows). The posterior one (red arrow) is mostly at the area of Angular gyrus, however it also encompasses some portions of the posterior superior temporal gyrus and posterior middle temporal gyrus. The anterior one (yellow one) encompasses mostly anterior superior temporal gyrus and inferior temporal gyrus . In my paper I need to name somehow this posterior STG/MTG cluster and this anterior STG/ITG region. How you suggest I avoid the confusion for the paper reader, given that previous literature sometimes name the anterior region MTG or STG.

Thanks a lot,

Vadim

 

 

 

 

I would name the regions as angular gyrus and anterior MTG, which aptly describes the largest regions affected.  The posterior region in the dominant hemisphere looks like Wernicke's area, sometimes described as posterior MTG in studies of semantics / comprehension.  (The anterior region is also sometimes activated in semantic studies.)

Thank you, Doug. Then I will probably name them pSTG and aSTG.

You are right regarding the pSTG  - it was indeed selective to language processing.

BTW, do you also see the pSTG as part of DMN activation? In my case the seed was in the PCC. People usually refer to this large posterior lateral blob as angylar gyrys / IPS, so I wondered whether it's a usual practice to get also the pSTG there.

 

Hi Vadim,

Best to use an anatomical reference that best describes that region (peak coordinates are commonly used for this). The angular gyrus is the more typical lateral parietal portion of the DMN (depending on methods used- notably on seed placement in seed-based methods). Here are the results from a PCC seed from task-free data in 892 older cognitively normal subjects. The lateral parietal region seen here is best characterized by the angular gyrus (I suspect yours is as well).  Anatomical landmarks for lobes, brodmann areas, etc can be helpful and depending on the platforms you are using there are packages to help you label the anatomic sites of interest.

Best,

Dave Jones

Thank you Dave.

Sure, large portion of the posterior lateral blob is the AG is in my data as well. pSTG is in addition.

BTW, I get relativley weak activations in the ventral ACC (compared to BA 10, for example). With 892 subjects the power should be higher, I guess...

I don’t find any ACC using the PCC seed based analysis I showed either…. So these analyses would be in agreement despite any power differences.  However, move the seed, change the dimensionality of an ICA analysis, or have a population with greater ACC involvement in MPFC and PCC based brain configurations and you will find ACC involvement with “DMN regions.”

Best,

Dave 

That being said, with increased power I can more confidently lower the threshold and then I do see the vACC and medial temporal lobe contributions. 

 

thnaks, this is useful for me to know




For the anatomical naming convention, I just have additional
suggestion. Sometime the naming varies a lot from study to study. I’d like to
suggest provide more information, e.g., anatomical name (with the reference
tools would be better), BA, and peak coordinates.

 

Yufeng

 

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Commented by David Jones (find37)

I don’t find any ACC using the PCC seed based analysis I
showed either…. So these analyses would be in agreement despite any power
differences.  However, move the seed, change the dimensionality of an ICA
analysis, or have a population with greater ACC involvement in MPFC and PCC
based brain configurations and you will find ACC involvement with “DMN
regions.”

src="/sites/default/files/images/mPFC.jpg">

Best,

Dave 



Online version of this post: href="http://rfmri.org/comment/2988#comment-2988">http://rfmri.org/comment/2988#comment-2988

 

thank you 

I plan to provide anyway coordinates list of my ROIs




I would agree with the later comments that it is best to refer to the region by the anatomical reference, including all the areas in a table that specifies maxima coordinates, etc.

 

How much angular vs. posterior middle (& superior) temporal gyrus is activated by language depends on the particular task, individual(s), and study.  Part of the DMN is more active during demanding language conditions, e.g., requiring conversion of information between visual & auditory modalities – which seems to contradict the idea that the DMN is most active when we are doing nothing. 

 

Personally, I think the DMN is involved in associative activity, so that by default we make associations between whatever stimuli and/or thoughts that occur simultaneously in time – there is decreased activity when we are doing a task so that irrelevant information does not interfere or create dysfunctional associations.  This hypothesis explains why demanding tasks [which nearly always require associations] are associated with more activity in the DMN than less demanding tasks, although not as much overall as at rest.  Furthermore, it explains the symptoms with neurological conditions such as Alzheimer’s that are associated with lower DMN activity – reduced ability to form new (associative) memories and loss of other abilities that require associative references (such as spatial navigation and math).

 

Doug Burman

                                                                                                                                                                                                                                                        


 






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