JiscMail Logo
Email discussion lists for the UK Education and Research communities

Help for FSL Archives


FSL Archives

FSL Archives


FSL@JISCMAIL.AC.UK


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

FSL Home

FSL Home

FSL  February 2008

FSL February 2008

Options

Subscribe or Unsubscribe

Subscribe or Unsubscribe

Log In

Log In

Get Password

Get Password

Subject:

AW: [FSL] AW: [FSL] Melodic output

From:

Andreas Bartsch <[log in to unmask]>

Reply-To:

FSL - FMRIB's Software Library <[log in to unmask]>

Date:

Thu, 14 Feb 2008 02:03:31 +0100

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (103 lines)

no


-----Ursprüngliche Nachricht-----
Von: FSL - FMRIB's Software Library im Auftrag von Michelle Voss
Gesendet: Do 14.02.2008 01:21
An: [log in to unmask]
Betreff: Re: [FSL] AW: [FSL] Melodic output
 
But if I want to flip both the sign of the timecourse and the spatial map, I
do not have to flip the subject loadings, right?

Michelle

On Feb 13, 2008 5:55 PM, Andreas Bartsch <
[log in to unmask]> wrote:

> Hi,
> in the full-tensor decomposition (TICA), you can decide which one you want
> to flip: if you change the sign of the timecourses (Tmodes) OR the spatial
> maps (Bmodes), you can also change the sign of the subject loadings (Smodes)
> AND keep the Bmodes OR the Tmodes, respectively.
> Cheers-
> Andreas
>
>
> -----Ursprüngliche Nachricht-----
> Von: FSL - FMRIB's Software Library im Auftrag von Michelle Voss
> Gesendet: Do 14.02.2008 00:39
> An: [log in to unmask]
> Betreff: Re: [FSL] Melodic output
>
> hello,
>
> just to double-check my intuition, since subject loadings are factor
> loadings, they do not need to be flipped here right? e.g.,  they represent
> the same thing for both the original and "flipped" maps and timecourses,
> which is how much each subject contributes to the component.
>
> thanks
> michelle
>
>
> On Feb 13, 2008 4:54 PM, Christian F. Beckmann <[log in to unmask]>
> wrote:
>
> > Hi
> >
> > red-yellow shows increasing positive regression coefficient with the
> > associated time course while dark blue-light blue shows increasing
> > negative regression coefficient wrt the time course.
> > If your time course is the inverse of your canonical design then blue
> > values who still show negative regression against the time course)
> > will in fact have positively regression coefficient wrt the original
> > design. That is, you can freely 'flip' the time course but then also
> > need to 'flip' the spatial map to make sure that once you multiply
> > these two together you get the same result (basically 1*1 = -1 * -1)
> > In TICA the associated time course basically is the avergae temporal
> > response across all the voxels (weighted y the vaue in the spatial
> > map) and also averaged across the population according to the subject/
> > session mode vector. Yes, you can trial average this time course and
> > get a representation of the overall avergae (across space and
> > population) average HRF shape.
> > best
> > christian
> >
> >
> >
> > On 13 Feb 2008, at 19:57, Vishwadeep Ahluwalia wrote:
> >
> > > Hi,
> > > I need help interpreting the IC maps. I'm confused about the color
> > > coding
> > > scheme.
> > > assuming my stimulus paradigm is such: 0001100011000
> > > Instance 1: i get a component with time series 0001100011000. How do i
> > > interpret the red and blue voxels?
> > > Instance 2: i get a component with time series 1110011100111. How do i
> > > interpret the red and blue voxels?
> > >
> > > As a separate question;
> > > Using TICA on 10 datasets, i got the task related component. Is it
> > > true that
> > > the time series for this component represents the time course of every
> > > activated voxel in the respective spatial map? if so, can i trial
> > > average
> > > this time course and validly estimate the shape of the BOLD response
> > > in
> > > those voxels?
> > > These ten datasets belong to one paradigm. Can i do a similar
> > > analysis on
> > > data from another paradigm(with different stimulus timings) and
> > > compare the
> > > effect sizes between the two paradigms? or would i have to run one
> > > single
> > > analysis for both?
> > >
> > > Thanks!
> > >
> > > -Vish
> >
>

Top of Message | Previous Page | Permalink

JiscMail Tools


RSS Feeds and Sharing


Advanced Options


Archives

March 2024
February 2024
January 2024
December 2023
November 2023
October 2023
September 2023
August 2023
July 2023
June 2023
May 2023
April 2023
March 2023
February 2023
January 2023
December 2022
November 2022
October 2022
September 2022
August 2022
July 2022
June 2022
May 2022
April 2022
March 2022
February 2022
January 2022
December 2021
November 2021
October 2021
September 2021
August 2021
July 2021
June 2021
May 2021
April 2021
March 2021
February 2021
January 2021
December 2020
November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
2006
2005
2004
2003
2002
2001


JiscMail is a Jisc service.

View our service policies at https://www.jiscmail.ac.uk/policyandsecurity/ and Jisc's privacy policy at https://www.jisc.ac.uk/website/privacy-notice

For help and support help@jisc.ac.uk

Secured by F-Secure Anti-Virus CataList Email List Search Powered by the LISTSERV Email List Manager