5
votes
Can we identify specific emotions on the basis of fMRI scans?
From meta-analyses that include musical emotion inductions, there is not much evidence that we can reliably distinguish between emotions in the brain, independent of the emotion induction procedure or ...
- 4,388
5
votes
Accepted
What do NaNs represent in an SPM β-map?
Apparently, this can happen when your ROI is near the edge of the brain as reported here. The thread is pretty old though so this might have been fixed by today and there is another reason in your ...
- 517
5
votes
Accepted
How to analyze event-related fMRI data with missing fMRI trigger in logfile?
I can see one case in which you still might analyze the data.
This only works under three conditions:
your paradigm has no variable durations of either stimulus presentations or breaks or others (or ...
- 517
4
votes
Accepted
Can memory access be detected via fMRI?
In theory, yes, because there are now many theories, supported by evidence, which map different memory processes onto different regions and patterns of activity in the brain.
In practice, there are ...
- 1,113
3
votes
where can i find preprocessed fmri data set for alzheimer's disease
See https://www.reddit.com/r/neuro/comments/5y4pta/does_anyone_know_where_i_can_find_a_repository_of/ for a similar question.
Websites that were posted there include http://www.humanconnectome.org/...
- 1,855
3
votes
Accepted
In fMRI analyses, what is the t-test actually comparing?
The coefficient is the measure of how strongly the given factor predicts the dependent variable, or in other words how much of the variance in the dependent variable can be explained by that factor. ...
- 146
3
votes
Activation of brain reasoning areas during dreaming
I cannot answer from fMRI's, but this theory conflicts with other anecdotal evidence from medicine.
In sensory deprivation, or under psychotomimetic substances, you can be awake and unimpaired ...
- 139
3
votes
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How was fMRI performed before EPI became available?
Short answer
Older image collection techniques like GRASS and FLASH are slower than EPI, but still fast enough to operate within the time span of the neurovascular delay.
Background
The speed of ...
- 20.5k
3
votes
Accepted
Why is my SPM batch job printing a warning repeatedly?
Below is a corrected version of the script. SPM seems to be quite finicky about the structure of the data passed to ...
- 1,493
3
votes
Accepted
Does only the time-series data of fMRI matter or does spatial distribution of the signal values also matter?
Usually, but not always, fMRI timeseries are used to compute functional connectivity by calculating Pearson correlations among voxels or ROIs.
The equation for the Pearson correlation can be written ...
- 7,221
2
votes
Generate fMRI from neurotransmitter consumption
It is not clear what neurotransmitter you are interested in, but one model that relates the PET ligand affinity to the cerebral blood volume (CBV) from fMRI looks like this:
Source:
Neurovascular ...
- 618
2
votes
Accepted
Generate fMRI from neurotransmitter consumption
The simplest equation for getting a BOLD signal from neurotransmitter that I could find was in "Tracing Problem Solving in Real Time: fMRI Analysis
of the Subject-paced Tower of Hanoi", which itself ...
- 8,833
2
votes
Open access 7T resting-state fMRI dataset
The Nighres project has released some 7T MRI datasets and tools to run them. You can read the paper on the tools here, and download the datasets from NITRC here.
2
votes
fMRI images: In-plane resolution, slice thickness
The information you seek is contained in the header of the image file. Matlab has open source tools for reading the header information. e.g., http://www.mathworks.com/matlabcentral/fileexchange/29344-...
- 171
2
votes
MRI images upside-down in FSLVIEW
Simply fslreorient2std will orient the images as you would expect.
From https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/Orientation%20Explained:
fslreorient2std - this ...
- 121
2
votes
Open fMRI data?
There was recently an issue about repositories for neuroimaging data. I just copied the table listing all of them from this paper. (Feel free to add links, I will do so when I have more time.)
Title, ...
2
votes
Can we identify specific emotions on the basis of fMRI scans?
Short answer
Pleasant and unpleasant music activate other areas of the cortex, potentially allowing for differentiation of music-related emotions based on fMRI scans alone.
Background
An fMRI study ...
- 20.5k
2
votes
How can I visualize DTI tractography streamlines generated from FSL's probtrackX in 3D?
I must say I am not an expert, but the following sources look helpful:
Gao et al. (2013) write
The voxel value in the resulting dataset represents the number of
streamline samples passing ...
- 20.5k
2
votes
"st" global variable in SPM8
it seems that it is a struct variable that is central to how images are visualized in spm. I found a description in the spm source code in this github repository (I linked to the exact line where it ...
- 517
2
votes
What does fMRI data look like after pre-processing?
The MRI signal is a small electrical current induced in the receiver coil by the precession of magnetization during resonance, i.e., a manifestation of Faraday's Law of Induction, wherein a changing ...
- 20.5k
2
votes
EEG in fMRI: High frequency "deltas" in EEG after gradient artifact removal
These seem to be simply gradient artifact remnants- Brain products analyzer didn't fully clean them.
Looking over the spectrogram of another EEG before the gradient artifact removal- it seems as if ...
- 31
2
votes
Accepted
What does 'Mean Diffusivity' tell me about the connectivity of cortical areas?
Short answer
The mean diffusivity (MD) in diffusion tensor imaging is a sensitive, yet a rather non-specific measure. Changes in MD tell you that water movement is altered, yet why and how will have ...
- 20.5k
2
votes
Difference between reverse inference and decoding (e.g. MVPA) in fMRI
Note. I initially scan read the question, I have rewritten my answer as a consequence, and due to the comments given.
As highlighted by others here Multi-voxel pattern analysis (MVPA) is an ...
- 1,196
2
votes
Accepted
Excluding psychometry and interview methods, is there any physical or molecular method that can confirm mild autism?
No.
The key term that will help you look for research about this is the word "biomarker".
There are certainly correlations with autism and some of the measurement techniques, but they aren't ...
- 7,221
2
votes
Accepted
Temporally truncate BOLD data
It looks like fslroi is the tool I'm looking for. To temporally truncate a scan the usage would be ...
- 141
2
votes
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View fMRI results with AAL3 atlas
I think to use the MRIcorn is the easiest way,
You can put the AAL3v1.nii.gz and AAL3v1.nii.txt into the mricron-templates folder.
by the way which software you use to do fMRI meta-analysis?
best,
...
- 36
2
votes
Accepted
BOLD->functional connectivity->spectral graph theory (e.g. Atasoy 2016) vs BOLD->Fourier Analysis
Interestingly enough, I myself have been reading papers like these for some weeks. Although I think your question does not have a correct answer (since it is a little bit open) I can try to give my ...
- 76
2
votes
Both using a strong magnetic field, why does TMS affect the brain but not MRI?
Relevant for the reaction of a physical system to an excitation is most of all the frequency spectrum of the signal. Most signals have a center frequency and a bandwidth, i.e. you can specify ...
- 121
1
vote
Accepted
How to fix a nii or rec file with partial volume
I found the solution using the python package nibabel.
The code is rather simple. If filename is your nii, or rec file use:
...
- 121
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