Reply-To: | | [log in to unmask][log in to unmask]> wrote:
> Many thanks Donald, > > Sorry but I may not got it right as I tried to plot but failed. > > Would be possible please if you can provide a small code or an example of > this plot? > > Regards, > > Aser > > On 2 Oct 2015, at 14:19, "MCLAREN, Donald" <[log in to unmask]> > wrote: > > To get a sense of this relationship, make a plot of Y=a*x+b*x^2. As you > will see, you have a linear and quadratic component. > > Best Regards, > Donald McLaren, PhD > > > On Fri, Oct 2, 2015 at 4:40 AM, fMRI <[log in to unmask]> wrote: > >> Many thanks Donald, >> >> Ok this makes sense now to me. However how about having the same voxel >> being significant in the linear term as well as the quadratic one even when >> looking at them individually (ie performinga t test at the linear regressor >> only and another one at the quadratic regressors only). This also even when >> the regressors are orthogonal ? >> >> Kind regards >> >> Aser >> >> On 30 Sep 2015, at 18:45, "MCLAREN, Donald" <[log in to unmask]> >> wrote: >> >> If I follow you have the PPI term, you have the the linear PM PPI term, >> and you have a quadratic PM PPI term. You found that only the quadratic PM >> PPI was non-zero. This is certainly possible. It means that the >> connectivity doesn't change with the task at the mean PM value, but >> increases as the PM value gets lower or higher. This would be a U-shaped >> effect of connectivity. If you look at y=x^2, then you can think of y being >> connectivity and and X being your PM. >> >> Best Regards, >> Donald McLaren, PhD >> >> >> On Wed, Sep 30, 2015 at 1:36 PM, Aser A <[log in to unmask]> wrote: >> >>> Hi Donald, >>> >>> I have another question related to the PM result. I sometime get >>> activations in the PPI of the PM but these activations are not significant >>> in the 0 order or the main effect result. Is this possible or usual ? How >>> this is can be explained ? >>> >>> Thanks >>> >>> Aser >>> >>> On Mon, Sep 28, 2015 at 11:19 AM, Aser A <[log in to unmask]> wrote: >>> >>>> Many thanks Donald, >>>> >>>> I have to admit that I did not quite get the method of the plot. But >>>> many thanks for the other comments >>>> >>>> On Fri, Sep 25, 2015 at 1:37 AM, MCLAREN, Donald < >>>> [log in to unmask]> wrote: >>>> >>>>> See below. >>>>> >>>>> Best Regards, >>>>> Donald McLaren, PhD >>>>> >>>>> >>>>> On Thu, Sep 24, 2015 at 4:28 PM, Aser A <[log in to unmask]> wrote: >>>>> >>>>>> Many thanks Donald. I saw in the article you mentioned a diagram that >>>>>> I did not understood it well. The one that shows the 25 % 50 or 75% >>>>>> connectivity in circles. >>>>>> >>>>>> From this I have these questions : >>>>>> >>>>>> - What does not mean and how it can be created ? >>>>>> >>>>> >>>>> I would suggest thbߦo |