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

Help for SPM Archives


SPM Archives

SPM Archives


SPM@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

SPM Home

SPM Home

SPM  July 2011

SPM July 2011

Options

Subscribe or Unsubscribe

Subscribe or Unsubscribe

Log In

Log In

Get Password

Get Password

Subject:

Re: how to build a {F} effect of interest in flexible factorial design

From:

"MCLAREN, Donald" <[log in to unmask]>

Reply-To:

MCLAREN, Donald

Date:

Thu, 14 Jul 2011 09:51:48 -0400

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (96 lines)

Here is an updated link:
http://www.martinos.org/~mclaren/ftp/presentations/

Best Regards, Donald McLaren
=================
D.G. McLaren, Ph.D.
Postdoctoral Research Fellow, GRECC, Bedford VA
Research Fellow, Department of Neurology, Massachusetts General Hospital and
Harvard Medical School
Office: (773) 406-2464
=====================
This e-mail contains CONFIDENTIAL INFORMATION which may contain PROTECTED
HEALTHCARE INFORMATION and may also be LEGALLY PRIVILEGED and which is
intended only for the use of the individual or entity named above. If the
reader of the e-mail is not the intended recipient or the employee or agent
responsible for delivering it to the intended recipient, you are hereby
notified that you are in possession of confidential and privileged
information. Any unauthorized use, disclosure, copying or the taking of any
action in reliance on the contents of this information is strictly
prohibited and may be unlawful. If you have received this e-mail
unintentionally, please immediately notify the sender via telephone at (773)
406-2464 or email.




On Tue, Jul 12, 2011 at 2:40 PM, MCLAREN, Donald
<[log in to unmask]> wrote:
> The main effect of subject doesn't exist, I'm assuming that you mean
> the main effect of group. The main effect of group is invalid in both
> the full and flexible factorial models (for more details see
> http://www.martinos.org/~mclaren/ftp/Utilities_DGM/OHBM2011_v3.pdf).
>
> Your question about a similar to eye() in the full factorial is a
> between-subject effect, do any of the group-condition combinations
> differ from 0. This can not be done in the current models as the error
> terms are wrong. You'd need to run a full/flex model for each
> condition and use the eye() in that model.
>
> If you want the main effect of group overall, you need to average the
> conditions and then use either the full or flexible factorial with
> just a group factor.
>
> To form the interaction terms in the current model. You first need to
> define them:
> (g1c1-g1c2) - (g2c1-g2c2)
> (g1c2-g1c3) - (g2c2-g2c3)
> (g1c3-g1c4) - (g2c3-g2c4)
> (g2c1-g2c2) - (g3c1-g3c2)
> (g2c2-g2c3) - (g3c2-g3c3)
> (g2c3-g2c4) - (g3c3-g3c4)
>
> Now, each row of the F-contrast will represent one of these. So you
> will have 6 rows in your interaction F. It should be straight forward
> to make it from the above details. The subject, group, and condition
> factors will have 0s for their columns.
>
> Best Regards, Donald McLaren
> =================
> D.G. McLaren, Ph.D.
> Postdoctoral Research Fellow, GRECC, Bedford VA
> Research Fellow, Department of Neurology, Massachusetts General Hospital and
> Harvard Medical School
> Office: (773) 406-2464
> =====================
> This e-mail contains CONFIDENTIAL INFORMATION which may contain PROTECTED
> HEALTHCARE INFORMATION and may also be LEGALLY PRIVILEGED and which is
> intended only for the use of the individual or entity named above. If the
> reader of the e-mail is not the intended recipient or the employee or agent
> responsible for delivering it to the intended recipient, you are hereby
> notified that you are in possession of confidential and privileged
> information. Any unauthorized use, disclosure, copying or the taking of any
> action in reliance on the contents of this information is strictly
> prohibited and may be unlawful. If you have received this e-mail
> unintentionally, please immediately notify the sender via telephone at (773)
> 406-2464 or email.
>
>
>
>
> On Mon, Jul 11, 2011 at 12:02 PM, Stefania Benetti
> <[log in to unmask]> wrote:
>> Dear SPMers and experts,
>>
>> I am running a fMRI analysis  with 4 conditions and 3 groups (g1=22,g2=17,g3=25). I am using a flexible factorial design with main effect of subject and interaction of groupXcondition.
>>
>> Along with the canonical contrasts, I now need to create a F contrast that reveals voxel showing some form of response that can be induced by the conditions, like the one that would be specified by using eye(12) in a full factorial design with the same conditions and groups.
>>
>> Is there a way to build this contrast in a flexible factorial design?
>>
>> Any help would be appreciated!
>>
>> Stefania
>>
>

Top of Message | Previous Page | Permalink

JiscMail Tools


RSS Feeds and Sharing


Advanced Options


Archives

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
2000
1999
1998


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

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