Optseq2 does not have the ability to change the identity of the stimuli during the run.
doug Gaber, Tilman wrote: > Thank you for your quick response. Initially I had the same idea. > Unfortunately, this easy solution does not work. All trials are successor of > the previous and predecessor of the following trial. Therefore we can't just > randomly distribute pairs of trials. The whole chain of trials has to be in > proper order. ([A-B-A-A-B-B-B-A-...] = [AB BA AA AB BB BA ...]) > My thinking was to somehow add these restrictions to the initial part of > optseq2 algorithm and fix for null event interuptions afterwards... > > Tilman > > > --------------------------------------------------------------------------------- > Tilman J. Gaber, Dipl.Psych. > Translational Neuroscience in Psychiatry and Neurology > Dpt. of Child and Adolescent Psychiatry and Psychotherapy > RWTH Aachen University > Neuenhofer Weg 21 > 52074 Aachen > Germany > > PHONE: +49-(0)241-80.85347 > FAX: +49-(0)241-80.3335070 > Email: tga...@ukaachen.de > ________________________________________ > Von: Douglas N Greve [gr...@nmr.mgh.harvard.edu] > Gesendet: Freitag, 26. Februar 2010 18:56 > An: Gaber, Tilman > Cc: freesurfer@nmr.mgh.harvard.edu > Betreff: Re: [Freesurfer] Optseq2 - Incorporate sequential order of trials as > a factor > > You can specify that there are 4 trial types (AA, AB, BA, BB), and give > the duration twice that of the individual. > > doug > > Gaber, Tilman wrote: > >> Dear mailinglist recipients, >> >> I am currently planning an optimized experiment using optseq2 and a 2x2 >> factors behavioral response task (Simon-task). >> The task consists of a pseudo-randomized series of two kinds of trials >> (congruent and incongruent). >> In addition there is a sequential factor, i.e. it is of interest whether a >> trial follows a trial of the same or the opposite kind. In other words there >> are (2x2) four different conditions where trials relate to precedent trials >> (AA,AB,BB,BA). >> Would it be possible to incorporate this sequential factor into the optseq2? >> I am aware that null events will fall between trials and thus interrupt >> trial sequences. Trials following null events would therefore be treated >> separately (i.e. for data analysis). In order to obtain an equal number of >> trials per condition, this would require increasing the number of trials >> depending on the number and order of null events. >> Currently I am able to produce a randomized order of equally balanced trials >> regarding trial type and sequential order (AA,AB,BB,BA). >> Any thoughts or suggestions are more than welcome! >> >> Best, >> Tilman >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> >> >> > > -- > Douglas N. Greve, Ph.D. > MGH-NMR Center > gr...@nmr.mgh.harvard.edu > Phone Number: 617-724-2358 > Fax: 617-726-7422 > > Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting > FileDrop: www.nmr.mgh.harvard.edu/facility/filedrop/index.html > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: www.nmr.mgh.harvard.edu/facility/filedrop/index.html _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu 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.
