Nicole

From Psych 221 Image Systems Engineering
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Background

Broad Context

- These data were collected as part of a larger study of transfer and the effectiveness of formula learning. - Materials: Polygon problem (IMAGES, etc.)


Example polygon problem stimuli.

Trial Paradigm

- In each trial, participants saw the stimulus, computed the answer and responded using the trackball. - The study timing was self-paced as in (ZEFFIRO REFERNCE) with jittering the ISI between each trial Schematic of each trial. Note self-paced task and jittered ISI.

Study Design

- Subjects received training before the scanner and then completed 3 trial blocks

Overall study design.


-- In the present investigation, we're only looking at 7 participants in condition 2 and only considering the 2 formula blocks (not the choice block and not considering the transfer questions outside of the scanner).


The present investigation: Subject Motion

(Example of subject motion graph(s).)


A Potential Solution: Interpolation Using Motion Correction Algorithms

Methods

Subjects

Seven healthy volunteers participated in this study. Their mean age was 23.8 years old and four participants were male. These data were collected as part of a larger sample of 16 healthy volunteers (mean age 23.2 years old).

MR acquisition

Data were obtained on a 3T GE scanner at Stanford's Center for Cognitive and Neurobiological Imaging (CNI)

MR Analysis

The MR data was analyzed using SPM software tools. (PUT LINK TO SPM HERE!) Specifically, ART repair was used (LINK)


Pre-processing

All data were slice-time corrected, motion corrected, and repeated scans were averaged together to create a single average scan for each subject.

Preprocessing pipeline with addition of ART repair step.

MNI space

MNI is an abbreviation for Montreal Neurological Institute.

After a pRF model was solved for each subject, the model was trasnformed into MNI template space. This was done by first aligning the high resolution t1-weighted anatomical scan from each subject to an MNI template. Since the pRF model was coregistered to the t1-anatomical scan, the same alignment matrix could then be applied to the pRF model.
Once each pRF model was aligned to MNI space, 4 model parameters - x, y, sigma, and r^2 - were averaged across each of the 6 subjects in each voxel.


Level 1 Analysis

Group Level Analyses

No Motion Correction

Some text. Some analysis. Some figures.

Using Motion Correction

Some text. Some analysis. Some figures.

Dropping A Subject With Too Much Motion

Some text. Some analysis. Some figures. Maybe some equations.


Equations

If you want to use equations, you can use the same formats that are use on wikipedia.
See wikimedia help on formulas for help.
This example of equation use is copied and pasted from wikipedia's article on the DFT.

The sequence of N complex numbers x0, ..., xN−1 is transformed into the sequence of N complex numbers X0, ..., XN−1 by the DFT according to the formula:

Xk=n=0N1xne2πiNknk=0,,N1

where i is the imaginary unit and e2πiN is a primitive N'th root of unity. (This expression can also be written in terms of a DFT matrix; when scaled appropriately it becomes a unitary matrix and the Xk can thus be viewed as coefficients of x in an orthonormal basis.)

The transform is sometimes denoted by the symbol , as in 𝐗={𝐱} or (𝐱) or 𝐱.

The inverse discrete Fourier transform (IDFT) is given by

xn=1Nk=0N1Xke2πiNknn=0,,N1.


Conclusions

Here is where you say what your results mean.

References - Resources and related work

References

Software

Art Repair

For more information about the SPM plugin ArtRepair, see: Art Repair