We have data from 200 college students using Freesurfer 4.5 Mac 10.6.8. We looked at both surface area and volume asymmetries. For surface area for Triangularis, there is a small leftward asymmetry averaged over the whole sample. 113 participants have leftward asymmetry and 85 have rightward asymmetries. For volume (for Triangularis), there is no significant asymmetry across the whole sample. 101 showed leftward asymmetry while 96 showed rightward asymmetry. This isn't surprising because parsT asymmetry is unreliable; sometimes you see it and sometimes you don't.
For pars Opercularis, the results are more robust. For surface area, there is a highly significant leftward asymmetry averaged over the whole sample; 158 participants have leftward asymmetries while 42 have rightward. For volume, parsO shows a significant leftward asymmetry across the whole sample. 145 leftward, 55 rightward. If the latest version of Freesurfer is showing predominately rightward asymmetries for pars triangularis, that doesn't seem right, but we wouldn't expect very strong leftward asymmetries either. Adam Felton and Christine Chiarello On Mon, Jun 25, 2012 at 5:55 AM, Bruce Fischl <[email protected]>wrote: > sure. Thanks for pointing out the BA44 issue. We'll put together a fix in > the next couple of weeks > Bruce > > On Mon, 25 Jun 2012, Gabor Perlaki wrote: > > Dear Bruce, >> >> I've checked the pars triangularis. It was right-lateralized in 79 >> subjects >> and left-lateralized in only 19 subjects. >> >> Thanks, Gabor >> >> 2012/6/23 Bruce Fischl <[email protected]> >> the structures don't need a threshold. Do you know that pars >> triangularis is left lateralized? For the BAs will get you a >> solution >> >> On Sat, 23 Jun 2012, Gabor Perlaki wrote: >> >> Dear Bruce, >> >> We don't used any thresholding by ourselves, we just >> took BA44 volumes out >> of the text-file in the stats directory. >> Should we use thresholded values instead of the >> volumes reported by the text >> files in the stats directory? >> Could we use the volumes reported by the aparc.stats >> and aseg.stats files >> for any statistical analyses, or do we need >> threshold that structures as >> well? >> >> >> Thanks, >> Gabor >> >> 2012/6/23 Bruce Fischl <[email protected]> >> Hi Gabor >> >> are you thresholding the BA4 label? In 5.2 we >> will distribute >> some tools to automatically threshold the >> labels so that the >> predicted area has the average area of the >> input labels. The >> right BA44 had more spatial spread than the >> left, so you might >> be including a lot of low probability vertices. >> >> cheers >> Bruce >> >> On Sat, 23 Jun 2012, Gabor Perlaki wrote: >> >> Dear Bruce, >> >> In the paper "Left-right asymmetry in >> volume and >> number of neurons in adult >> Broca's area." by Katrin Amunts, 10 >> subjects (5 men >> and 5 women) were >> studied, and the volume of BA44 was >> greater in the >> left hemisphere than in >> the right in all ten cases. So, it is >> very strange >> that the volume of BA44 >> was greater in the right hemisphere in >> all of the 80 >> subjects analyzed by >> Eniko. >> >> Thanks, >> Gabor >> >> >> >> >> The information in this e-mail is intended only for >> the person to whom >> it is >> addressed. If you believe this e-mail was sent to >> you in error and the >> e-mail >> contains patient information, please contact the >> Partners Compliance >> HelpLine at >> >> http://www.partners.org/**complianceline<http://www.partners.org/complianceline>. >> If the >> e-mail was sent to you >> in error >> but does not contain patient information, please >> contact the sender >> and properly >> dispose of the e-mail. >> >> >> >> >> >> >> > _______________________________________________ > Freesurfer mailing list > [email protected] > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > The information in this e-mail is intended only for the person to whom it > is > addressed. If you believe this e-mail was sent to you in error and the > e-mail > contains patient information, please contact the Partners Compliance > HelpLine at > http://www.partners.org/complianceline . If the e-mail was sent to you in > error > but does not contain patient information, please contact the sender and > properly > dispose of the e-mail. > >
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