6
votes
Are there any studies (fMRI scans, etc) showing why some people (supposedly) are more open to hypnotism?
Overall, while there are developing cognitive neuroscience theories of how hypnotic states are produced, there does not appear to be any known cognitive neuroscience basis for individual differences ...
- 6,982
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 ...
- 4,377
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
5
votes
How to get anatomical masks?
I'm a TMS, but not an fMRI, researcher but I have experience using anatomical masks. I can guide you through the steps to make an anatomical mask, but unfortunately I don't have any code to offer you.
...
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 ...
- 1,093
4
votes
Accepted
Neurophysiological indications of focus and motivation
Focus and motives are very different cognitive processes. Essentially focus would be attention, while motivation is a complex neurocognitive process, such as hunger or thirst, which drives attentional ...
- 1,175
4
votes
Accepted
Reference request for creator of heuristic for processing fMRI data (T.Nichols)
I know very little about fmri, but as @strongbad points out, surely it is Professor Thomas Nichols at Warwick.
I'm not sure what the authoritative reference is, but Luo and Nichols (2003) might be ...
- 30.7k
3
votes
Accepted
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 ...
- 20.4k
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
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
Accepted
Slices and aquisition of fMRI
I will focus on question #1:
Analysis of MRI scans is typically done using voxels (Fig. 1). Voxels have a volume defined by three dimensions (length, width and depth).
Voxel analysis. Source: ...
- 20.4k
3
votes
Why "fractional" anisotropy?
Like lea's comment indicated, FA is called "fractional" anisotropy simply because it's the degree of anisotropic diffusion, i.e., a ratio (Soares, Marques, Alves and Sousa, 2013).
Fractional ...
- 6,982
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
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
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 ...
- 6,994
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
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 ...
- 628
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 ...
- 8,813
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
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 ...
- 1,175
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 ...
- 20.4k
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 ...
- 20.4k
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 ...
- 20.4k
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 ...
- 20.4k
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